@article{zhang2024,
title = {Isothermal thermoluminescence dating of speleothem growth – A case study from Bleßberg cave 2,},
author = {Junjie Zhang and Jennifer Klose and Denis Scholz and Norbert Marwan and Sebastian F. M. Breitenbach and Lutz Katzschmann and Dennis Kraemer and Sumiko Tsukamoto},
doi = {10.1016/j.quageo.2024.101628},
year = {2024},
date = {2024-09-21},
urldate = {2024-09-21},
journal = {Quaternary Geochronology},
volume = {85},
pages = {101628},
abstract = {Speleothems are a key archive of past climatic and environmental changes. 230Th/U dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper 230Th/U dating, and samples older than 600 ka also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of 238U, 234U, 230Th and their decay constants. We use the 230Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the 230Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the 230Th/U-method and for samples that are unsuitable for U-series dating methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Speleothems are a key archive of past climatic and environmental changes. 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute. dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper 230Th/U dating, and samples older than 600 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr. also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of 238U, 234U, 230Th and their decay constants. We use the 230Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the 230Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the 230Th/U-method and for samples that are unsuitable for U-series dating methods.
@misc{zhang2023,
title = {Isothermal thermoluminescence (ITL) dating of a speleothem from Bleßberg Cave},
author = {J. Zhang and J. Klose and M. Sierralta and S. Tsukamoto and D. Scholz and N. Marwan and S. Breitenbach},
editor = {17th International Luminescence and Electron Spin Resonance Dating conference (LED2023), Copenhagen (Denmark)},
year = {2023},
date = {2023-06-29},
urldate = {2023-06-29},
abstract = {The calcite thermoluminescence (TL) signal (280 °C peak) saturates at much higher doses (saturation dose up to 5000 Gy) compared to quartz and feldspar, which shows great potential to extend the dating limit. However, spurious TL signal occurred at the high temperature range hindered its application. The conventional multiple-aliquot additive-dose (MAAD) protocol used for TL dating applies extrapolation for equivalent dose (De) estimation, which also has large error. Isothermal TL (ITL) dating with the single-aliquot regenerative-dose (SAR) protocol might be a promising way as it reduces the influence of the spurious TL signal, and it applies interpolation to obtain the De. However, this protocol has not been tested on samples with independent age control.
This study tests the ITL SAR dating protocol on a speleothem sample from Bleßberg cave, which has been accurately dated with 230Th/U (ca. 320–425 ka). ITL measurement at 235 °C for 200 °C can remove the 280 °C TL peak completely without TL contribution from higher temperature range. ITL De shows a plateau when the ITL temperature varies between 230 °C and 240 °C. Peak shifting and isothermal annealing tests indicate the 280 °C TL peak has a lifetime of tens of millions years at 10 °C, which is stable enough for the age range of this speleothem sample. The accurate alpha efficiency (α-value) and the U, Th distribution within the sample are measured to estimate the dose rate. The dose rate variation with time due to U-series disequilibrium is corrected for. The ITL ages are compared with the 230Th/U ages to evaluate the performance of the ITL dating protocol.},
note = {17th International Luminescence and Electron Spin Resonance Dating conference (LED2023), Copenhagen (Denmark)},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
The calcite thermoluminescence (TL) signal (280 °C peak) saturates at much higher doses (saturation dose up to 5000 Gy) compared to quartz and feldspar, which shows great potential to extend the dating limit. However, spurious TL signal occurred at the high temperature range hindered its application. The conventional multiple-aliquot additive-dose (MAAD) protocol used for TL dating applies extrapolation for equivalent dose (De) estimation, which also has large error. Isothermal TL (ITL) dating with the single-aliquot regenerative-dose (SAR) protocol might be a promising way as it reduces the influence of the spurious TL signal, and it applies interpolation to obtain the De. However, this protocol has not been tested on samples with independent age control.
This study tests the ITL SAR dating protocol on a speleothem sample from Bleßberg cave, which has been accurately dated with 230Th/U (ca. 320–425 ka). ITL measurement at 235 °C for 200 °C can remove the 280 °C TL peak completely without TL contribution from higher temperature range. ITL De shows a plateau when the ITL temperature varies between 230 °C and 240 °C. Peak shifting and isothermal annealing tests indicate the 280 °C TL peak has a lifetime of tens of millions years at 10 °C, which is stable enough for the age range of this speleothem sample. The accurate alpha efficiency (α-value) and the U, Th distribution within the sample are measured to estimate the dose rate. The dose rate variation with time due to U-series disequilibrium is corrected for. The ITL ages are compared with the 230Th/U ages to evaluate the performance of the ITL dating protocol.
This study examines the method of isothermal thermoluminescence dating to determine the age of speleothems. Traditional methods for dating cave formations, such as U/ThU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute. dating, are challenging for very old samples. At LIAG, the stalagmite BB2-1 was used to investigate how thermoluminescence dating can be adjusted to provide accurate ages. Since light exposure on the stalagmite can affect the dating results, part of the material was removed using a special acid to minimize this effect. Additionally, it was tested how light might still influence the results. The age estimates were compared with U/Th ages measured at the University of Mainz, and they are in good agreement within the margin of error. This study thus demonstrates that thermoluminescence dating can provide reliable age estimates for particularly old speleothems.
Comparison of dating results of BB2-1 using U/Th dating and TL dating
@phdthesis{klose2023phd,
title = {Quantitative multi-proxy climate reconstruction for MIS 3 in Central Europe based on precisely dated speleothems from Bleßberg Cave, Germany},
author = {Jennifer Klose},
editor = {Johannes Gutenberg University Mainz},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/Klose_Thesis_Jennifer-Klose.pdf},
doi = {10.25358/openscience-10558},
year = {2024},
date = {2024-05-01},
urldate = {2024-05-01},
abstract = {Speläotheme zeichnen sich als sensitive Klimaarchive aus und haben sich in letzten
Jahrzehnten als solche etabliert. Sie haben das Potential wertvolle Informationen über das
Paläoklima kontinuierlich aufzuzeichnen und können mit den Uran-
Ungleichgewichtsmethoden präzise datiert werden. Das Berechnen von unabhängigen
Altersmodellen kombiniert mit Analysen verschiedener Klimaproxys, wie δ18O und δ13C,
Spurenelementen oder Tropfwassereinschlüssen ermöglicht es, hochaufgelöste
Paläoklimarekonstruktionen zu erstellen.
Dansgaard-Oeschger (DO)-Ereignisse sind kurzfristige Klimaschwankungen über
einige hunderte oder wenige tausende Jahre, welche vor allem während der marinen
Isotopenstufe 3 (MIS 3, ca. 60 - 30 ka BP) auftraten. Obwohl erste Beweise für die
Ereignisse in grönländischen Eisbohrkernen entdeckt wurden, sind sie mittlerweile global
nachweisbar. DO-Ereignisse zeichnen sich durch eine rasche Erwärmung, gefolgt von
gradueller Abkühlung aus, während das MIS 3 generell als eine kältere Periode definiert
ist. Daher wurde die Tatsache, dass bisher kaum zentraleuropäische Speläotheme aus dem
MIS 3 gefunden wurden, mit zu kaltem oder trockenem Klima begründet. Im Rahmen
dieser Arbeit wurden drei MIS 3 Speläotheme aus der Bleßberg Höhle in Deutschland
detailliert untersucht. Durch die Kombination von lösungs-basierter und in-situ
Laserablation 230Th/U-Datierung konnte das komplexe Wachstum der Proben präzise
aufgeschlüsselt werden.
Es konnten mehrere Wachstumsepisoden im MIS 3 identifiziert werden, welche primär
zeitgleich zu DO-Ereignissen in Grönland auftraten. Die Wachstumsphasen wurde daher
als eigenständiger Proxy für günstige Klimabedingungen für Speläothemwachstum
etabliert, d.h. Perioden mit ausreichender Boden- und Vegetationsbedeckung über der
Höhle und der Möglichkeit das Tropfwasser in die Höhle gelangt. Darüber hinaus wurde
eine multi-Proxy Analyse durchgeführt mit dem Ziel möglichst vielfältige Informationen
über das MIS 3 in Mitteleuropa zu erhalten. Ein langfristiger Trend zeigt die generelle
Verschlechterung des Klimas mit Fortschreiten des MIS 3 auf. Eine besonders warme und
kontinuierliche Wachstumsphase trat zeitgleich mit DO14 auf. Außerdem wurden zwei
kurzzeitige Kälteereignisse innerhalb des DO14 aufgezeichnet, welches die hohe
Sensitivität der Speläotheme aus der Bleßberg Höhle verdeutlicht.
Weitere kurzzeitige Klimaereignisse wurden während des spätglazialen Teils der
Speläothem-Proben (ca. 14,5 - 1,7 ka BP) aufgezeichnet und ein hochauflösender multi-
Proxy-Datensatz, der das Holozän (11,7 ka BP - rezent) bis 0,6 ka BP abdeckt, wurde
erstellt.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
SpeläothemeSpeläothemSekundäre Mineralablagerungen in Höhlen, wie Sinter, Stalagmiten, Stalaktiten, usw. zeichnen sich als sensitive Klimaarchive aus und haben sich in letzten
Jahrzehnten als solche etabliert. Sie haben das Potential wertvolle Informationen über das
Paläoklima kontinuierlich aufzuzeichnen und können mit den Uran-
Ungleichgewichtsmethoden präzise datiert werden. Das Berechnen von unabhängigen AltersmodellenAltersmodellNach der Datierung eines Stalagmiten werden allen anderen Messungen (z. B. Isotopenverhältnisse), die ursprünglich entlang einer Längen-Achse durchgeführt wurden, ein Alter zugeordnet. kombiniert mit Analysen verschiedener Klimaproxys, wie δ18O und δ13C,
Spurenelementen oder Tropfwassereinschlüssen ermöglicht es, hochaufgelöste
Paläoklimarekonstruktionen zu erstellen.
Dansgaard-Oeschger (DO)-Ereignisse sind kurzfristige Klimaschwankungen über
einige hunderte oder wenige tausende Jahre, welche vor allem während der marinen
Isotopenstufe 3 (MIS 3MIS 3"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. "MIS 3" bedeutet dabei eine kurzzeitige Warmphase (beginnend vor 57 Tausend Jahren) während der letzten Eiszeit., ca. 60 - 30 ka BPka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.) auftraten. Obwohl erste Beweise für die
Ereignisse in grönländischen Eisbohrkernen entdeckt wurden, sind sie mittlerweile global
nachweisbar. DO-Ereignisse zeichnen sich durch eine rasche Erwärmung, gefolgt von
gradueller Abkühlung aus, während das MIS 3 generell als eine kältere Periode definiert
ist. Daher wurde die Tatsache, dass bisher kaum zentraleuropäische Speläotheme aus dem
MIS 3 gefunden wurden, mit zu kaltem oder trockenem Klima begründet. Im Rahmen
dieser Arbeit wurden drei MIS 3 Speläotheme aus der Bleßberg Höhle in Deutschland
detailliert untersucht. Durch die Kombination von lösungs-basierter und in-situ
Laserablation 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute.-DatierungDatierungUm einem Stalagmiten oder gar einer einzelnen Wachstumslage im Stalagmiten ein Alter zuordnen zu können, muß eine Datierung durchgeführt werden. Dies erfolgt in der Regel radiometrisch, d. h. über die Messung von Zerfallsprodukten (siehe auch U/Th-Datierung). konnte das komplexe Wachstum der Proben präzise
aufgeschlüsselt werden.
Es konnten mehrere Wachstumsepisoden im MIS 3 identifiziert werden, welche primär
zeitgleich zu DO-Ereignissen in Grönland auftraten. Die Wachstumsphasen wurde daher
als eigenständiger ProxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. für günstige Klimabedingungen für Speläothemwachstum
etabliert, d.h. Perioden mit ausreichender Boden- und Vegetationsbedeckung über der
Höhle und der Möglichkeit das Tropfwasser in die Höhle gelangt. Darüber hinaus wurde
eine multi-ProxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. Analyse durchgeführt mit dem Ziel möglichst vielfältige Informationen
über das MIS 3 in Mitteleuropa zu erhalten. Ein langfristiger Trend zeigt die generelle
Verschlechterung des Klimas mit Fortschreiten des MIS 3 auf. Eine besonders warme und
kontinuierliche Wachstumsphase trat zeitgleich mit DO14 auf. Außerdem wurden zwei
kurzzeitige Kälteereignisse innerhalb des DO14 aufgezeichnet, welches die hohe
Sensitivität der Speläotheme aus der Bleßberg Höhle verdeutlicht.
Weitere kurzzeitige Klimaereignisse wurden während des spätglazialen Teils der SpeläothemSpeläothemSekundäre Mineralablagerungen in Höhlen, wie Sinter, Stalagmiten, Stalaktiten, usw.-Proben (ca. 14,5 - 1,7 ka BP) aufgezeichnet und ein hochauflösender multi-
Proxy-Datensatz, der das HolozänHolozänDer jüngste Abschnitt der geologischen Zeitgeschichte, etwa die letzten 11.700 Jahre. (11,7 ka BP - rezent) bis 0,6 ka BP abdeckt, wurde
erstellt.
@proceedings{klose2023poster,
title = {Timing of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and D. Scholz and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan},
editor = {Summer School on Speleothem Sciences 2023, Sao Paulo},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/klose_SummerschoolSaoPaulo2023.pdf},
year = {2023},
date = {2023-08-07},
urldate = {2023-08-07},
abstract = {The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.},
howpublished = {Poster},
note = {Summer School on Speleothem Sciences 2023, Sao Paulo},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
The last glacial period and especially Marine IsotopeIsotopChemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. stage 3 (MIS 3, ca. 57 - 27 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.
Klose, J.; Scholz, D.; Weber, M.; Vonhof, H.; Plessen, B.; Breitenbach, S.; Marwan, N.
Timing and progression of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany Proceedings
@proceedings{klose2023,
title = {Timing and progression of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and D. Scholz and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan},
editor = {XXI INQUA Conference, Rome (Italy)},
year = {2023},
date = {2023-07-19},
urldate = {2023-07-19},
abstract = {Speleothems can be dated with unprecedented precision using U-series disequilibrium methods and provide numerous climate proxies, such as stable oxygen (δ18O) and carbon isotopes (δ13C) or trace elements, resulting in long, sometimes continuous climate proxy records. Therefore, speleothems have great potential for reconstruction of past climate variability during Marine Isotope Stage (MIS) 3 and precise determination of the timing and duration of Dansgaard-Oeschger (D/O) events. While first discovered in Greenland ice cores, various speleothem records around the globe provided clear evidence for the supra-regional character of the D/O events. However, MIS 3 speleothem records from Central Europe are very limited. Here we present three spleothem (flowstone) MIS 3 records from Bleßberg Cave, Germany.
All flowstones show episodic growth with distinctive, partially very thin (<2 mm) growth phases, interrupted by visible hiatuses consisting of detrital material. Precise and accurate 230Th/U dating of the individual growth phases is challenging due to potential detrital contamination from these layers. Combining different sampling and analytical techniques, we were able to date even the thinnest growth layers with very high precision, i.e., 2σ-age uncertainties of at most a few hundred years.
The timing of the growth phases aligns with several D/O events, which have not been recorded in other Central European speleothems yet. The δ18O and δ13C records of all three flowstones are highly correlated which suggests a dominant process influencing both isotope systems. Comparison with the Sr and Mg records provides evidence for a strong influence of Prior Calcite Precipitation (PCP) in the aquifer above and inside the cave on the stable isotope and trace element signals. In addition, all proxy records are interpreted as evidence for past changes in precipitation and vegetation density and document a clear trend from more humid climate during early MIS 3 (ca. 57 – 50 ka) to less humid conditions during mid and late MIS 3 (ca. 45 – 30 ka).
Our multi-proxy approach thus allows us not only to precisely determine the timing, duration, and progression of several D/O events, but also to deepen our general understanding of climate variability during MIS 3 in Central Europe.},
howpublished = {Poster},
note = {XXI INQUA Conference, Rome (Italy)},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Speleothems can be dated with unprecedented precision using U-series disequilibrium methods and provide numerous climate proxiesProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet., such as stable oxygen (δ18O) and carbon isotopes (δ13C) or trace elements, resulting in long, sometimes continuous climate proxy records. Therefore, speleothems have great potential for reconstruction of past climate variability during Marine Isotope Stage (MISMIS"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. Die MIS werden rückwärts nummeriert (also größere Zahl = älter) und ungerade Zahlen stehen für Warmzeiten, gerade für Kaltzeiten.) 3 and precise determination of the timing and duration of Dansgaard-Oeschger (D/O) events. While first discovered in Greenland ice cores, various speleothem records around the globe provided clear evidence for the supra-regional character of the D/O events. However, MIS 3 speleothem records from Central Europe are very limited. Here we present three spleothem (flowstone) MIS 3 records from Bleßberg Cave, Germany.
All flowstones show episodic growth with distinctive, partially very thin (<2 mm) growth phases, interrupted by visible hiatuses consisting of detrital material. Precise and accurate 230Th/U dating of the individual growth phases is challenging due to potential detrital contamination from these layers. Combining different sampling and analytical techniques, we were able to date even the thinnest growth layers with very high precision, i.e., 2σ-age uncertainties of at most a few hundred years.
The timing of the growth phases aligns with several D/O events, which have not been recorded in other Central European speleothems yet. The δ18O and δ13C records of all three flowstones are highly correlated which suggests a dominant process influencing both isotope systems. Comparison with the Sr and Mg records provides evidence for a strong influence of Prior Calcite Precipitation (PCP) in the aquifer above and inside the cave on the stable isotope and trace element signals. In addition, all proxy records are interpreted as evidence for past changes in precipitation and vegetation density and document a clear trend from more humid climate during early MIS 3 (ca. 57 – 50 ka) to less humid conditions during mid and late MIS 3 (ca. 45 – 30 ka).
Our multi-proxy approach thus allows us not only to precisely determine the timing, duration, and progression of several D/O events, but also to deepen our general understanding of climate variability during MIS 3 in Central Europe.
@proceedings{klose2022,
title = {Timing of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan and D. Scholz},
editor = {KR9 in Innsbruck, 2022},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/klose_KR9-Innsbruck2022.pdf},
year = {2022},
date = {2022-07-19},
urldate = {2022-07-19},
abstract = {The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.},
howpublished = {Poster},
note = {KR9 Konferenz in Innsbruck},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.
@proceedings{klose2021,
title = {Determination of phases of warm climate during MIS 3 in Central Europe based on precisely dated speleothems from Bleßberg Cave, Germany},
author = {Jennifer Klose and Denis Scholz and Sebastian F. M. Breitenbach and Birgit Plessen and Hubert Vonhof},
editor = {GeoKarlsruhe 2021: Sustainable Earth – From processes to resources},
year = {2021},
date = {2021-09-22},
urldate = {2021-09-22},
abstract = {Speleothems provide a great opportunity for paleoclimate reconstruction because they occur almost worldwide and can be dated very precisely using the U-series disequilibrium method. The most commonly used climate proxies are stable isotope values (δ18O and δ13C) and trace elements. However, these are influenced by a variety of surface and in-cave processes, which results in a non-trivial interpretation of the speleothem proxy signals.
The last glacial period and in particular the Marine Isotope Stage (MIS) 3 is, compared to the recent warm phase, the Holocene, characterised by larger climate oscillations. These are detectable in δ18O records from Greenland ice cores and also climate archives in Europe, such as pollen or tree ring records. Unfortunately, little direct proxy evidence is available from central Europe, and the climatic and environmental conditions during MIS 3 remain largely enigmatic. Speleothem records from central Europe during MIS 3 are limited due to cold climate conditions and mainly restricted to the warmer southern or alpine regions.
Here we present the first results of two flowstones from Bleßberg Cave in Germany. Preliminary 230Th/U-ages make these flowstones the most northern continental growth of speleothems during MIS 3 in central Europe. Thus, these samples provide the unique opportunity to reconstruct climate variability during parts of the last glacial period. With the combination of several different proxies, such as stable isotopes, trace elements and the results from cave monitoring, we will be able to obtain detailed insights into environmental conditions in central Europe during MIS 3 and the Late Glacial.},
howpublished = {Poster},
note = {GeoKarlsruhe 2021: Sustainable Earth – From processes to resources, Karlsruhe},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Speleothems provide a great opportunity for paleoclimate reconstruction because they occur almost worldwide and can be dated very precisely using the U-series disequilibrium method. The most commonly used climate proxies are stable isotope values (δ18O and δ13C) and trace elements. However, these are influenced by a variety of surface and in-cave processes, which results in a non-trivial interpretation of the speleothem proxy signals.
The last glacial period and in particular the Marine Isotope Stage (MIS) 3 is, compared to the recent warm phase, the Holocene, characterised by larger climate oscillations. These are detectable in δ18O records from Greenland ice cores and also climate archives in Europe, such as pollen or tree ring records. Unfortunately, little direct proxy evidence is available from central Europe, and the climatic and environmental conditions during MIS 3 remain largely enigmatic. Speleothem records from central Europe during MIS 3 are limited due to cold climate conditions and mainly restricted to the warmer southern or alpine regions.
Here we present the first results of two flowstones from Bleßberg Cave in Germany. Preliminary 230Th/U-ages make these flowstones the most northern continental growth of speleothems during MIS 3 in central Europe. Thus, these samples provide the unique opportunity to reconstruct climate variability during parts of the last glacial period. With the combination of several different proxies, such as stable isotopes, trace elements and the results from cave monitoring, we will be able to obtain detailed insights into environmental conditions in central Europe during MIS 3 and the Late Glacial.
Growth phases of Bleßberg speleothems in comparison to other climate data:
(a) Antarctic Bottom Water (AABW) reconstruction based on Pa/Th data from core CDH19 from the Bermuda Rise (dark turquoise line).
(b) Red Sea sea level reconstruction (dark blue line).
(c) North Atlantic sea ice cover reconstruction, based on PbIP25 (an isoprenoid lipid) from the southeastern Norwegian Sea (light turquoise line with triangles).
(d) Summer sea surface temperatures (SST) based on alkenone measurements from core MD01-2444 at the Iberian Margin (37°N, black line).
(e, f, and g): Vegetation reconstructions based on pollen data from grasses (green), spruce (dark green), and hornbeam (yellow-green) from different Eifel Maar cores (AU3, AU4, HM4).
(h) Ice rafted debris (IRD) from core MD01-2040 at the Iberian Margin (40°N, light orange).
(i) Combined relative frequency of growth of all three Bleßberg speleothem samples with more than 30% positive slopes in the age model (red). The leads and lags between the onset of DO events in Greenland and the onset of speleothem growth in Bleßberg Cave are indicated. DO events (grey) and Heinrich events (blue) are marked by colored bars.
This scientific study analyzes the speleothem growth phases in the Bleßberg Cave based on the sinter samples BB-9, BB-10, and BB-15 to investigate climatic changes during Marine Isotope Stage 3 (MIS 3), approximately 60,000 to 30,000 years ago. The speleothem growth phases coincide with warm and humid climate periods that mark so-called Dansgaard-Oeschger events (DO events). These events were characterized by rapid warming during the last ice age.
A total of nine growth phases were identified, eight of which correlate with DO events such as 16, 14–11 (60.14 – 48.55 ka BP) and 8–6 (38.12 – 32.82 ka BP). These phases occurred during periods of strong Atlantic Ocean currents, warm sea surface temperatures, and reduced sea ice coverage. The most notable growth phase occurred during DO14 (53.4 – 50.4 ka BP), the longest and warmest event of MIS 3. During this time, dense vegetation consisting of Picea and Carpinus trees dominated, indicating particularly favorable climate conditions in Central Europe.
The analysis of carbon isotopes (δ13C), oxygen isotopes (δ18O), and calcium isotopes (δ44/42Ca) plays an important role. The δ13C values show a trend towards higher values over the course of MIS 3, indicating drier conditions and a less developed soil and vegetation cover. Calcium isotopes also confirm the trend towards a drier climate, as calcium tends to precipitate before speleothem formation, which happens more frequently under dry conditions. The study of vegetation shows that it changed from non-woody plants to woody vegetation, particularly between 53,000 and 51,000 years ago. Later, it shifted back to non-woody plants, reflecting drier conditions. The oxygen isotopes also indicate a trend towards colder conditions in the later stages of MIS 3.
During DO14 (approximately 53,500 to 50,500 years ago), there was a warm, humid climate with well-developed soils and dense vegetation, which enabled continuous speleothem growth. At the end of this phase, two cold events occurred, leading to a decline in vegetation and drier, colder conditions.
Overall, the speleothem data from Bleßberg Cave provide important insights into the climate during MIS 3 and highlight that alternating periods of moisture and dryness influenced the growth of the speleothems.
@article{zhang2024,
title = {Isothermal thermoluminescence dating of speleothem growth – A case study from Bleßberg cave 2,},
author = {Junjie Zhang and Jennifer Klose and Denis Scholz and Norbert Marwan and Sebastian F. M. Breitenbach and Lutz Katzschmann and Dennis Kraemer and Sumiko Tsukamoto},
doi = {10.1016/j.quageo.2024.101628},
year = {2024},
date = {2024-09-21},
urldate = {2024-09-21},
journal = {Quaternary Geochronology},
volume = {85},
pages = {101628},
abstract = {Speleothems are a key archive of past climatic and environmental changes. 230Th/U dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper 230Th/U dating, and samples older than 600 ka also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of 238U, 234U, 230Th and their decay constants. We use the 230Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the 230Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the 230Th/U-method and for samples that are unsuitable for U-series dating methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Speleothems are a key archive of past climatic and environmental changes. 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute. dating is the most commonly used method to determine speleothem ages. However, incorporation of non-radiogenic thorium may hamper 230Th/U dating, and samples older than 600 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr. also remain out-of-reach. Calcite exhibits a thermoluminescence (TL) signal at 280 °C with a high characteristic saturation dose, and provides significant potential to date carbonate samples over several million years. Hitherto, the application of TL dating for calcite has mainly been hindered by two factors: 1) a spurious TL signal occurring in the high temperature range, and 2) non-uniform dose rate due to U-series disequilibrium. Here we test an isothermal TL (ITL) dating method on a speleothem sample from Bleßberg cave 2, Germany. We show that the ITL signal measured at 240 °C can completely remove the 280 °C TL peak with a negligible TL contribution from the higher temperature range, thus reducing the influence from the spurious signal. The time-dependent dose rate variation can be simulated using the initial radioactivity of 238U, 234U, 230Th and their decay constants. We use the 230Th/U dating method to provide precise and accurate radiometric ages documenting that the speleothem grew between 425.5 ± 5.4 and 320.5 ± 9.7 ka. The ITL ages (421 ± 23 to 311 ± 23 ka) of four subsamples from the speleothem are consistent with the 230Th/U ages at isochronous sampling positions, showing the general reliability of the ITL dating method. ITL dating provides a pathway to construct chronologies for palaeoclimate reconstructions for speleothems beyond the range of the 230Th/U-method and for samples that are unsuitable for U-series dating methods.
@phdthesis{klose2023phd,
title = {Quantitative multi-proxy climate reconstruction for MIS 3 in Central Europe based on precisely dated speleothems from Bleßberg Cave, Germany},
author = {Jennifer Klose},
editor = {Johannes Gutenberg University Mainz},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/Klose_Thesis_Jennifer-Klose.pdf},
doi = {10.25358/openscience-10558},
year = {2024},
date = {2024-05-01},
urldate = {2024-05-01},
abstract = {Speläotheme zeichnen sich als sensitive Klimaarchive aus und haben sich in letzten
Jahrzehnten als solche etabliert. Sie haben das Potential wertvolle Informationen über das
Paläoklima kontinuierlich aufzuzeichnen und können mit den Uran-
Ungleichgewichtsmethoden präzise datiert werden. Das Berechnen von unabhängigen
Altersmodellen kombiniert mit Analysen verschiedener Klimaproxys, wie δ18O und δ13C,
Spurenelementen oder Tropfwassereinschlüssen ermöglicht es, hochaufgelöste
Paläoklimarekonstruktionen zu erstellen.
Dansgaard-Oeschger (DO)-Ereignisse sind kurzfristige Klimaschwankungen über
einige hunderte oder wenige tausende Jahre, welche vor allem während der marinen
Isotopenstufe 3 (MIS 3, ca. 60 - 30 ka BP) auftraten. Obwohl erste Beweise für die
Ereignisse in grönländischen Eisbohrkernen entdeckt wurden, sind sie mittlerweile global
nachweisbar. DO-Ereignisse zeichnen sich durch eine rasche Erwärmung, gefolgt von
gradueller Abkühlung aus, während das MIS 3 generell als eine kältere Periode definiert
ist. Daher wurde die Tatsache, dass bisher kaum zentraleuropäische Speläotheme aus dem
MIS 3 gefunden wurden, mit zu kaltem oder trockenem Klima begründet. Im Rahmen
dieser Arbeit wurden drei MIS 3 Speläotheme aus der Bleßberg Höhle in Deutschland
detailliert untersucht. Durch die Kombination von lösungs-basierter und in-situ
Laserablation 230Th/U-Datierung konnte das komplexe Wachstum der Proben präzise
aufgeschlüsselt werden.
Es konnten mehrere Wachstumsepisoden im MIS 3 identifiziert werden, welche primär
zeitgleich zu DO-Ereignissen in Grönland auftraten. Die Wachstumsphasen wurde daher
als eigenständiger Proxy für günstige Klimabedingungen für Speläothemwachstum
etabliert, d.h. Perioden mit ausreichender Boden- und Vegetationsbedeckung über der
Höhle und der Möglichkeit das Tropfwasser in die Höhle gelangt. Darüber hinaus wurde
eine multi-Proxy Analyse durchgeführt mit dem Ziel möglichst vielfältige Informationen
über das MIS 3 in Mitteleuropa zu erhalten. Ein langfristiger Trend zeigt die generelle
Verschlechterung des Klimas mit Fortschreiten des MIS 3 auf. Eine besonders warme und
kontinuierliche Wachstumsphase trat zeitgleich mit DO14 auf. Außerdem wurden zwei
kurzzeitige Kälteereignisse innerhalb des DO14 aufgezeichnet, welches die hohe
Sensitivität der Speläotheme aus der Bleßberg Höhle verdeutlicht.
Weitere kurzzeitige Klimaereignisse wurden während des spätglazialen Teils der
Speläothem-Proben (ca. 14,5 - 1,7 ka BP) aufgezeichnet und ein hochauflösender multi-
Proxy-Datensatz, der das Holozän (11,7 ka BP - rezent) bis 0,6 ka BP abdeckt, wurde
erstellt.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
SpeläothemeSpeläothemSekundäre Mineralablagerungen in Höhlen, wie Sinter, Stalagmiten, Stalaktiten, usw. zeichnen sich als sensitive Klimaarchive aus und haben sich in letzten
Jahrzehnten als solche etabliert. Sie haben das Potential wertvolle Informationen über das
Paläoklima kontinuierlich aufzuzeichnen und können mit den Uran-
Ungleichgewichtsmethoden präzise datiert werden. Das Berechnen von unabhängigen AltersmodellenAltersmodellNach der Datierung eines Stalagmiten werden allen anderen Messungen (z. B. Isotopenverhältnisse), die ursprünglich entlang einer Längen-Achse durchgeführt wurden, ein Alter zugeordnet. kombiniert mit Analysen verschiedener Klimaproxys, wie δ18O und δ13C,
Spurenelementen oder Tropfwassereinschlüssen ermöglicht es, hochaufgelöste
Paläoklimarekonstruktionen zu erstellen.
Dansgaard-Oeschger (DO)-Ereignisse sind kurzfristige Klimaschwankungen über
einige hunderte oder wenige tausende Jahre, welche vor allem während der marinen
Isotopenstufe 3 (MIS 3MIS 3"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. "MIS 3" bedeutet dabei eine kurzzeitige Warmphase (beginnend vor 57 Tausend Jahren) während der letzten Eiszeit., ca. 60 - 30 ka BPka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.) auftraten. Obwohl erste Beweise für die
Ereignisse in grönländischen Eisbohrkernen entdeckt wurden, sind sie mittlerweile global
nachweisbar. DO-Ereignisse zeichnen sich durch eine rasche Erwärmung, gefolgt von
gradueller Abkühlung aus, während das MIS 3 generell als eine kältere Periode definiert
ist. Daher wurde die Tatsache, dass bisher kaum zentraleuropäische Speläotheme aus dem
MIS 3 gefunden wurden, mit zu kaltem oder trockenem Klima begründet. Im Rahmen
dieser Arbeit wurden drei MIS 3 Speläotheme aus der Bleßberg Höhle in Deutschland
detailliert untersucht. Durch die Kombination von lösungs-basierter und in-situ
Laserablation 230Th/U-DatierungDatierungUm einem Stalagmiten oder gar einer einzelnen Wachstumslage im Stalagmiten ein Alter zuordnen zu können, muß eine Datierung durchgeführt werden. Dies erfolgt in der Regel radiometrisch, d. h. über die Messung von Zerfallsprodukten (siehe auch U/Th-Datierung). konnte das komplexe Wachstum der Proben präzise
aufgeschlüsselt werden.
Es konnten mehrere Wachstumsepisoden im MIS 3 identifiziert werden, welche primär
zeitgleich zu DO-Ereignissen in Grönland auftraten. Die Wachstumsphasen wurde daher
als eigenständiger ProxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. für günstige Klimabedingungen für Speläothemwachstum
etabliert, d.h. Perioden mit ausreichender Boden- und Vegetationsbedeckung über der
Höhle und der Möglichkeit das Tropfwasser in die Höhle gelangt. Darüber hinaus wurde
eine multi-ProxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. Analyse durchgeführt mit dem Ziel möglichst vielfältige Informationen
über das MIS 3 in Mitteleuropa zu erhalten. Ein langfristiger Trend zeigt die generelle
Verschlechterung des Klimas mit Fortschreiten des MIS 3 auf. Eine besonders warme und
kontinuierliche Wachstumsphase trat zeitgleich mit DO14 auf. Außerdem wurden zwei
kurzzeitige Kälteereignisse innerhalb des DO14 aufgezeichnet, welches die hohe
Sensitivität der Speläotheme aus der Bleßberg Höhle verdeutlicht.
Weitere kurzzeitige Klimaereignisse wurden während des spätglazialen Teils der SpeläothemSpeläothemSekundäre Mineralablagerungen in Höhlen, wie Sinter, Stalagmiten, Stalaktiten, usw.-Proben (ca. 14,5 - 1,7 ka BP) aufgezeichnet und ein hochauflösender multi-
Proxy-Datensatz, der das HolozänHolozänDer jüngste Abschnitt der geologischen Zeitgeschichte, etwa die letzten 11.700 Jahre. (11,7 ka BP - rezent) bis 0,6 ka BP abdeckt, wurde
erstellt.
@misc{zhang2023,
title = {Isothermal thermoluminescence (ITL) dating of a speleothem from Bleßberg Cave},
author = {J. Zhang and J. Klose and M. Sierralta and S. Tsukamoto and D. Scholz and N. Marwan and S. Breitenbach},
editor = {17th International Luminescence and Electron Spin Resonance Dating conference (LED2023), Copenhagen (Denmark)},
year = {2023},
date = {2023-06-29},
urldate = {2023-06-29},
abstract = {The calcite thermoluminescence (TL) signal (280 °C peak) saturates at much higher doses (saturation dose up to 5000 Gy) compared to quartz and feldspar, which shows great potential to extend the dating limit. However, spurious TL signal occurred at the high temperature range hindered its application. The conventional multiple-aliquot additive-dose (MAAD) protocol used for TL dating applies extrapolation for equivalent dose (De) estimation, which also has large error. Isothermal TL (ITL) dating with the single-aliquot regenerative-dose (SAR) protocol might be a promising way as it reduces the influence of the spurious TL signal, and it applies interpolation to obtain the De. However, this protocol has not been tested on samples with independent age control.
This study tests the ITL SAR dating protocol on a speleothem sample from Bleßberg cave, which has been accurately dated with 230Th/U (ca. 320–425 ka). ITL measurement at 235 °C for 200 °C can remove the 280 °C TL peak completely without TL contribution from higher temperature range. ITL De shows a plateau when the ITL temperature varies between 230 °C and 240 °C. Peak shifting and isothermal annealing tests indicate the 280 °C TL peak has a lifetime of tens of millions years at 10 °C, which is stable enough for the age range of this speleothem sample. The accurate alpha efficiency (α-value) and the U, Th distribution within the sample are measured to estimate the dose rate. The dose rate variation with time due to U-series disequilibrium is corrected for. The ITL ages are compared with the 230Th/U ages to evaluate the performance of the ITL dating protocol.},
note = {17th International Luminescence and Electron Spin Resonance Dating conference (LED2023), Copenhagen (Denmark)},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
The calcite thermoluminescence (TL) signal (280 °C peak) saturates at much higher doses (saturation dose up to 5000 Gy) compared to quartz and feldspar, which shows great potential to extend the dating limit. However, spurious TL signal occurred at the high temperature range hindered its application. The conventional multiple-aliquot additive-dose (MAAD) protocol used for TL dating applies extrapolation for equivalent dose (De) estimation, which also has large error. Isothermal TL (ITL) dating with the single-aliquot regenerative-dose (SAR) protocol might be a promising way as it reduces the influence of the spurious TL signal, and it applies interpolation to obtain the De. However, this protocol has not been tested on samples with independent age control.
This study tests the ITL SAR dating protocol on a speleothem sample from Bleßberg cave, which has been accurately dated with 230Th/U (ca. 320–425 ka). ITL measurement at 235 °C for 200 °C can remove the 280 °C TL peak completely without TL contribution from higher temperature range. ITL De shows a plateau when the ITL temperature varies between 230 °C and 240 °C. Peak shifting and isothermal annealing tests indicate the 280 °C TL peak has a lifetime of tens of millions years at 10 °C, which is stable enough for the age range of this speleothem sample. The accurate alpha efficiency (α-value) and the U, Th distribution within the sample are measured to estimate the dose rate. The dose rate variation with time due to U-series disequilibrium is corrected for. The ITL ages are compared with the 230Th/U ages to evaluate the performance of the ITL dating protocol.
@bachelorthesis{kuehne2023,
title = {Spurenelementanalyse eines Speläothems der Marinen Isotopenstadien 9 und 11 aus der Blessberghöhle},
author = {Sofia Kühne},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/Bachelorarbeit_Sofia_Kuehne_2753456.pdf},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
school = {Johannes-Gutenberg-Universität Mainz},
abstract = {Die vorliegende Arbeit befasst sich mit einem Speläothem aus der Blessberghöhle in Thüringen. Diese Probe hatte jeweils eine Wachstumsphase während des Marinen Isotopenstadiums 11 und während des Marinen Isotopenstadiums 9. Dazwischen scheint es zu einem Wachstumsstopp gekommen zu sein. Die Probe wurde bereits datiert und auf Sauerstoff- und Kohlenstoffisotope untersucht, wobei im Rahmen dieser Arbeit zusätzlich die Spurenelemente gemessen wurden. Durch die Interpretation dieser Daten lassen sich Schlüsse über das Klima ziehen. Allerdings ist die genaue Analyse der Daten komplex, weshalb der Vergleich mit globalen Klimatrends von großer Bedeutung ist.
Für das MIS 11 deuten die Daten auf eine sich verändernde Umwelt in Richtung trockeneres und vegetationsärmeres Klima hin, das aufgrund der abflachenden globalen Temperatur zu dieser Zeit erklärt werden kann. Es lässt sich anhand von einer schnelleren Wachstumsrate auf erhöhten Niederschlag während des Wachstums schließen, im Gegensatz zum MIS 9. Im Bezug auf das MIS 9 sind keine eindeutigen Schlussfolgerungen möglich, doch das stabile Verhalten der Werte lässt darauf schließen, dass das Klima während des Höhepunkts des MIS 9-Wachstums (9e) nur geringe Veränderungen aufwies. Diese sind nicht eindeutig zu interpretieren, da unterschiedliche Argumente für oder gegen Vegetationswachstum und Niederschlagsmengen vorliegen.
Es ist jedoch zu berücksichtigen, dass die Interpretation der vorliegenden Daten Unsicherheiten birgt. Zusätzliche Informationen wie ein Vergleich zu Proben aus der Höhle, die zur gleichen Zeit wuchsen, sowie mehr Wissen über lokale Faktoren, die die Höhlenbedingungen beeinflusst haben und weitere Altersdatierungen könnten zu einer akkurateren Deutung führen. Daher wären weitere Forschungsarbeiten erforderlich, um die aufgestellten Vermutungen zu verifizieren und um ein umfassenderes Bild der vergangenen Gegebenheiten zu erhalten.},
keywords = {},
pubstate = {published},
tppubtype = {bachelorthesis}
}
Die vorliegende Arbeit befasst sich mit einem Speläothem aus der Blessberghöhle in Thüringen. Diese Probe hatte jeweils eine Wachstumsphase während des Marinen Isotopenstadiums 11 und während des Marinen Isotopenstadiums 9. Dazwischen scheint es zu einem Wachstumsstopp gekommen zu sein. Die Probe wurde bereits datiert und auf Sauerstoff- und Kohlenstoffisotope untersucht, wobei im Rahmen dieser Arbeit zusätzlich die SpurenelementeSpurenelementEin Spurenelement ist ein chemisches Element genannt, das nur in geringer Konzentration in einer Probe vorhanden ist. Tropfsteine bestehen fast ausschließlich aus Kalziumkarbonat, also aus den Elementen Kalzium, Kohlenstoff und Sauerstoff. Andere Elemente kommen nur in sehr geringen Konzentrationen vor, sind aber vorhanden. Deren Konzentration hängt oft von den während der Entstehung des Tropfsteins herrschenden Umweltbedingungen ab. gemessen wurden. Durch die Interpretation dieser Daten lassen sich Schlüsse über das Klima ziehen. Allerdings ist die genaue Analyse der Daten komplexKomplexe SystemeKomplexe Systeme bestehen aus sehr vielen Komponenten, die auch miteinander wechselwirken, zeigen unvorhersagbares Verhalten und können trotzdem charakteristische Muster hervorrufen (weshalb sie sich deutlich von rein zufälligen Systemen unterscheiden)., weshalb der Vergleich mit globalen Klimatrends von großer Bedeutung ist.
Für das MISMIS"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. Die MIS werden rückwärts nummeriert (also größere Zahl = älter) und ungerade Zahlen stehen für Warmzeiten, gerade für Kaltzeiten. 11 deuten die Daten auf eine sich verändernde Umwelt in Richtung trockeneres und vegetationsärmeres Klima hin, das aufgrund der abflachenden globalen Temperatur zu dieser Zeit erklärt werden kann. Es lässt sich anhand von einer schnelleren Wachstumsrate auf erhöhten Niederschlag während des Wachstums schließen, im Gegensatz zum MIS 9. Im Bezug auf das MIS 9 sind keine eindeutigen Schlussfolgerungen möglich, doch das stabile Verhalten der Werte lässt darauf schließen, dass das Klima während des Höhepunkts des MIS 9-Wachstums (9e) nur geringe Veränderungen aufwies. Diese sind nicht eindeutig zu interpretieren, da unterschiedliche Argumente für oder gegen Vegetationswachstum und Niederschlagsmengen vorliegen.
Es ist jedoch zu berücksichtigen, dass die Interpretation der vorliegenden Daten Unsicherheiten birgt. Zusätzliche Informationen wie ein Vergleich zu Proben aus der Höhle, die zur gleichen Zeit wuchsen, sowie mehr Wissen über lokale Faktoren, die die Höhlenbedingungen beeinflusst haben und weitere Altersdatierungen könnten zu einer akkurateren Deutung führen. Daher wären weitere Forschungsarbeiten erforderlich, um die aufgestellten Vermutungen zu verifizieren und um ein umfassenderes Bild der vergangenen Gegebenheiten zu erhalten.
@bachelorthesis{geier2022,
title = {^{230}Th/U – Datierung eines Speläothems der Marinen Isotopenstadien 9 und 11 aus der Bleßberghöhle in Thüringen},
author = {Florian Geier},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/Bachelorarbeit-Florian-Geier-2744515.pdf},
year = {2022},
date = {2022-06-01},
urldate = {2022-06-01},
school = {Johannes-Gutenberg-Universität Mainz},
abstract = {Im Zuge des gegenwärtigen Klimawandels gewinnen Rekonstruktionen des vergangenen Klimas zunehmend an Bedeutung, da durch sie klimatische Entwicklungen besser verstanden werden können. Speläotheme bilden ein terrestrisches Archiv, welche mittels der 230Th/U-Datierung absolut und sehr präzise datiert werden können. Die datierten Wachstumsphasen von Speläothemen liefern unmittelbar Rückschlüsse auf vergangene klimatische Gegebenheiten, da ihr Wachstum von der Tropfwasser- und damit der Niederschlagswasserverfügbarkeit abhängen. Aus diesen Wachstumsphasen lassen sich wärmere und feuchtere Zeiträume abgrenzen (Interglaziale). Der Stalagmit BB2‘1 aus der Bleßberghöhle im südlichen Thüringen wurde mit dieser Methode datiert. Sein Wachstum fand in den Interglazialen Marines Isoptenstadium (MIS) 11e-c und MIS 9e statt. Besonders im MIS 11e wurde viel Wachstum des BB2‘1 verzeichnet. Im Vergleich mit anderen Klimaarchiven können die klimatischen Bedingungen um die Bleßberghöhle in einen globalen Kontext gesetzt werden. Es zeigt sich, dass das Klima um die Bleßberghöhle an globale, klimatische Veränderungen gekoppelt war und sehr früh auf diese reagierte.},
keywords = {},
pubstate = {published},
tppubtype = {bachelorthesis}
}
Im Zuge des gegenwärtigen Klimawandels gewinnen Rekonstruktionen des vergangenen Klimas zunehmend an Bedeutung, da durch sie klimatische Entwicklungen besser verstanden werden können. Speläotheme bilden ein terrestrisches Archiv, welche mittels der 230Th/U-Datierung absolut und sehr präzise datiert werden können. Die datierten Wachstumsphasen von Speläothemen liefern unmittelbar Rückschlüsse auf vergangene klimatische Gegebenheiten, da ihr Wachstum von der Tropfwasser- und damit der Niederschlagswasserverfügbarkeit abhängen. Aus diesen Wachstumsphasen lassen sich wärmere und feuchtere Zeiträume abgrenzen (Interglaziale). Der Stalagmit BB2‘1 aus der Bleßberghöhle im südlichen Thüringen wurde mit dieser Methode datiert. Sein Wachstum fand in den Interglazialen Marines Isoptenstadium (MIS) 11e-c und MIS 9e statt. Besonders im MIS 11e wurde viel Wachstum des BB2‘1 verzeichnet. Im Vergleich mit anderen Klimaarchiven können die klimatischen Bedingungen um die Bleßberghöhle in einen globalen Kontext gesetzt werden. Es zeigt sich, dass das Klima um die Bleßberghöhle an globale, klimatische Veränderungen gekoppelt war und sehr früh auf diese reagierte.
@inproceedings{sierralta2015,
title = {Insights in Bleßberg cave: Speleothem chronology and geochemical research},
author = {Melanie Sierralta and Lutz Katzschmann and Wilhelm Nikonow and Dieter Rammlmair},
year = {2015},
date = {2015-03-23},
booktitle = {75. Jahrestagung der Deutsche Geophysikalische Gesellschaft in Hannover},
abstract = {During construction works on the railway network between Ebensfeld and Erfurt a karst cave was found in the Bleßberg tunnel. The so called „Bleßberg Cave“ developed in limestone of the Lower Muschelkalk. The investigations by the Geological Survey of Thuringia (TLUG), the mining agency of Thuringia, and the incorporated society of cave explorer in Thuringia revealed impressing objects (stalagmites, stalactites, sinter, excentriques, cave lake, cave creek), which were partly sampled; furthermore the extent of the cave was measured. The more than 1000 m long cave had no natural entrance. Based on interdisciplinary studies on the sampled material information about the development and age of the cave will be obtained. Speleothem represent an impressive and unique archive for climate and palaeoenvironmental changes. The growth of stalagmites can be linked to warm climate phases of past. In these warm stages, the growth of stalagmites depends on the precipitation and the water supply; thus palaeoenvironmental conditions are preserved. The aim of this study is to decode the environmental condi- tions using high resolution techniques. Selected stalagmites and sinters were radiometrically dated by 230Th/U and analysed for their stable isotopic compositions. Furthermore, micro-energy dispersive X-ray fluorescence analyses were performed to evaluate trace element dis- tribution and identify growth phases of the speleothem. Most elements revealed the layered texture of the specimen while distribution of Al recorded the fractures. Some visibly identified hiatuses could be associated with changes in chemistry (Si, Fe). The determined 230Th/U ages on several speleothem samples range between 6 ka and 360 ka. In combination with high res- olution stable isotope investigation they provide insights into climatic changes from MIS 11 to the Holocene.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
During construction works on the railway network between Ebensfeld and Erfurt a karst cave was found in the Bleßberg tunnel. The so called „Bleßberg Cave“ developed in limestone of the Lower Muschelkalk. The investigations by the Geological Survey of Thuringia (TLUG), the mining agency of Thuringia, and the incorporated society of cave explorer in Thuringia revealed impressing objects (stalagmites, stalactites, sinter, excentriques, cave lake, cave creek), which were partly sampled; furthermore the extent of the cave was measured. The more than 1000 m long cave had no natural entrance. Based on interdisciplinary studies on the sampled material information about the development and age of the cave will be obtained. Speleothem represent an impressive and unique archive for climate and palaeoenvironmental changes. The growth of stalagmites can be linked to warm climate phases of past. In these warm stages, the growth of stalagmites depends on the precipitation and the water supply; thus palaeoenvironmental conditions are preserved. The aim of this study is to decode the environmental condi- tions using high resolution techniques. Selected stalagmites and sinters were radiometrically dated by 230Th/U and analysed for their stable isotopic compositions. Furthermore, micro-energy dispersive X-ray fluorescence analyses were performed to evaluate trace element dis- tribution and identify growth phases of the speleothem. Most elements revealed the layered texture of the specimen while distribution of Al recorded the fractures. Some visibly identified hiatuses could be associated with changes in chemistry (Si, Fe). The determined 230Th/U ages on several speleothem samples range between 6 ka and 360 ka. In combination with high res- olution stable isotopeIsotopChemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. investigation they provide insights into climatic changes from MIS 11 to the Holocene.
Some initial investigations on BB2-1 from the Blessberg Cave 2 were already performed at the LIAG in 2014/15, such as age dating, initial trace element and oxygen isotope analyses. Thus the approximate age of the stalagmite was known: 360 to 301 ka BP.
In 2022, as part of a bachelor thesis at the University of Mainz, the stalagmite BB2-1 was systematically dated and the new ages evaluated. For this purpose, 14 dating samples were taken and dated in the Isotope Geochemical Palaeoclimatology working group at the University of Mainz by means of U/ThU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute. dating on a more modern system than at LIAG. Possible detritical content were taken into account and the ages corrected accordingly. The ages are, therefore, significantly more accurate than those already known.
The oldest age was found at the base of the stalagmite, as expected. It is 425.46 ± 5.43 ka BP. The youngest age, at the top of the stalagmite, is 320.49 ± 9.58 ka BP. The ages in between do not change uniformly. In the lower 4/5 of the stalagmite, all ages are older than 400 ka BP. Only in the upper fifth of the stalagmite the ages are significantly younger and range between 341.31 and 320.49 ka BP.
Stalagmite BB2/1 with drill sites (red) of the individual samples with the measured and corrected ages.
This allows us to define the growth phases of the stalagmite: The lower, larger part grew in isotope stage 11, the upper, younger part in isotope stage 9. Both stages are warm periods. The stalgamite did not grow in the cold periods before, in between, and after. It is interesting that growth only occurred in the beginning phases of these warm periods, which are warmer than the following phases within the isotope stage in question (growth in MIS 11e to 11c as well as in MIS 9e). After that, no more stalagmite growth took place, not even in more recent warm periods, which suggests a change in the hydrological conditions.
@article{Kaufmann2020,
title = {Modelling long-term and short-term evolution of karst in vicinity of tunnels},
author = {Georg Kaufmann and Douchko Romanov},
doi = {10.1016/j.jhydrol.2019.124282},
year = {2020},
date = {2020-02-01},
journal = {Journal of Hydrology},
volume = {581},
pages = {124282},
abstract = {Tunnel construction offers unique insights into the interior structure of rock massifs. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolostone, gypsum, and anhydrite are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures. We model the long-term development of karst features and the evolution of phreatic and epi-phreatic caves below the Schalkau Plateau in the Triassic limestone with a numerical karst evolution model. With hydrological boundary conditions derived from local meteorological data and karst springs, and a simplified model of the local lithology, our model predicts the increase in secondary permeability in the karst aquifer. Enlarged fracture zones develop at locations, where cave systems have been explored. Thus our long-term evolution model can successfully predict karst features in the Schalkau Plateau. Applying the karst evolution model on a short-term period, we assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the Bleßberg Cave and its longer-term stability. Our model results suggest that flow through the cave section beneath the tunnel, which has been filled with concrete and blocks, is blocked and that during flood events the impounded water will accelerate the development of by-passes around the artificial infill.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tunnel construction offers unique insights into the interior structure of rock massifs. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolostone, gypsum, and anhydrite are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures. We model the long-term development of karst features and the evolution of phreatic and epi-phreatic caves below the Schalkau Plateau in the Triassic limestone with a numerical karst evolution model. With hydrological boundary conditions derived from local meteorological data and karst springs, and a simplified model of the local lithology, our model predicts the increase in secondary permeability in the karst aquifer. Enlarged fracture zones develop at locations, where cave systems have been explored. Thus our long-term evolution model can successfully predict karst features in the Schalkau Plateau. Applying the karst evolution model on a short-term period, we assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the Bleßberg Cave and its longer-term stability. Our model results suggest that flow through the cave section beneath the tunnel, which has been filled with concrete and blocks, is blocked and that during flood events the impounded water will accelerate the development of by-passes around the artificial infill.
@inproceedings{kaufmann2019egu,
title = {Karst and trains: The challenge of railway tunneling},
author = {Georg Kaufmann and Douchko Romanov},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2021/04/EGU2019-3554.pdf},
year = {2019},
date = {2019-04-08},
booktitle = {Geophysical Research Abstracts},
volume = {21},
pages = {EGU2019-3554},
abstract = {Tunnel construction offers unique insights into the interior structure of landscapes. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolomite, gypsum, and above all anhydrite, are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water and the hydration of anhydrite with the sub-sequent precipitation of gypsum during the drilling pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures.
We report on a high-speed railway tunnel in Germany along the line Berlin-Munich. The Blessberg-Tunnel, about 8,3 km long, mainly traverses Ordovician quarzites and shales, but along its southern end it crosses the Frankonian line, a major fault zone, with Triassic limestones on the southern part of the fault. Here, a substantial active water cave, the Blessberg Cave, has been encountered during tunnel construction.
We attempt to explain the karst features along the Frankonian line, the evolution of active water caves in the Triassic limestones south of the fault, and try to assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the cave and its longer-term stability.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Tunnel construction offers unique insights into the interior structure of landscapes. Soluble rocks encountered during tunnel construction, however, pose a substantial challenge. Especially classical karst rocks such as limestone, dolomite, gypsum, and above all anhydrite, are unpredictable during tunnel excavation. The enlarged voids created by the long-term dissolution of the soluble rocks in contact with water and the hydration of anhydrite with the sub-sequent precipitation of gypsum during the drilling pose risks because of possible uncontrollable water inflow and of instability of the encountered cave voids, which often requires expensive remediation measures.
We report on a high-speed railway tunnel in Germany along the line Berlin-Munich. The Blessberg-Tunnel, about 8,3 km long, mainly traverses Ordovician quarzites and shales, but along its southern end it crosses the Frankonian line, a major fault zone, with Triassic limestones on the southern part of the fault. Here, a substantial active water cave, the Blessberg Cave, has been encountered during tunnel construction.
We attempt to explain the karst features along the Frankonian line, the evolution of active water caves in the Triassic limestones south of the fault, and try to assess the effect of consolidation measures taken to stabilise the tunnel cross section in vicinity of the cave and its longer-term stability.
The strength and speed of karstification depends on various parameters, such as water balance or the existing rocks. A karstification model was used to model how karstification had developed in the area of the Schalkauer Platte and how it will develop in the future.
The model shows regional differences in the karstification potential. Especially in the areas where the model calculated increased karstification, there are, indeed, more caves, including the Blessberg cave. The modelling of future karst development, especially in the area of the cave part under the tunnel that was blocked during tunnel construction, showed a substantial increase in karstification in this area, i.e., a faster widening of fissures and crevices (in the time frame of 100 to 200 years).
@article{Keiner2013,
title = {Raman Spectroscopy—An Innovative and Versatile Tool To Follow the Respirational Activity and Carbonate Biomineralization of Important Cave Bacteria},
author = {Robert Keiner and Torsten Frosch and Stefan Hanf and Anna Rusznyak and Denise M Akob and Kirsten Küsel and Jürgen Popp},
doi = {10.1021/ac401699d},
year = {2013},
date = {2013-09-01},
urldate = {2013-09-01},
journal = {Analytical Chemistry},
volume = {85},
number = {18},
pages = {8708–8714},
abstract = {Raman gas spectrometry is introduced as a unique tool for the investigation of the respiratory activity that is indicative for growth of bacteria involved in biomineralization. Growth of these bacteria cannot be monitored using conventional turbidity-based optical density measurements due to concomitant mineral formation in the medium. The respiratory activity of carbonate-precipitating Arthrobacter sulfonivorans, isolated from the recently discovered Herrenberg Cave, was investigated during its lifecycle by means of innovative cavity-enhanced Raman gas analysis. This method allowed rapid and nonconsumptive online quantification of CO2 and O2 in situ in the headspace of the bacterial culture. Carbon dioxide production rates of A. sulfonivorans showed two maxima due to its pleomorphic growth lifecycle. In contrast, only one maximum was observed in control organism Pseudomonas fluorescens with a one-stage lifecycle. Further insight into the biomineralization process over time was provided by a combination of Raman macro- and microspectroscopy. With the help of this spatially resolved chemical imaging of the different types of calcium carbonate minerals, it was elucidated that the surface of the A. sulfonivorans bacterial cells served as nuclei for biomineralization of initially spherical vaterite precipitates. These vaterite biominerals continued growing as chemically stable rock-forming calcite crystals with rough edges. Thus, the utilization of innovative Raman multigas spectroscopy, combined with Raman mineral analysis, provided novel insights into microbial-mediated biomineralization and, therefore, provides a powerful methodology in the field of environmental sciences.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Raman gas spectrometry is introduced as a unique tool for the investigation of the respiratory activity that is indicative for growth of bacteria involved in biomineralization. Growth of these bacteria cannot be monitored using conventional turbidity-based optical density measurements due to concomitant mineral formation in the medium. The respiratory activity of carbonate-precipitating Arthrobacter sulfonivorans, isolated from the recently discovered Herrenberg Cave, was investigated during its lifecycle by means of innovative cavity-enhanced Raman gas analysis. This method allowed rapid and nonconsumptive online quantification of CO2 and O2 in situ in the headspace of the bacterial culture. Carbon dioxide production rates of A. sulfonivorans showed two maxima due to its pleomorphic growth lifecycle. In contrast, only one maximum was observed in control organism Pseudomonas fluorescens with a one-stage lifecycle. Further insight into the biomineralization process over time was provided by a combination of Raman macro- and microspectroscopy. With the help of this spatially resolved chemical imaging of the different types of calcium carbonate minerals, it was elucidated that the surface of the A. sulfonivorans bacterial cells served as nuclei for biomineralization of initially spherical vaterite precipitates. These vaterite biominerals continued growing as chemically stable rock-forming calcite crystals with rough edges. Thus, the utilization of innovative Raman multigas spectroscopy, combined with Raman mineral analysis, provided novel insights into microbial-mediated biomineralization and, therefore, provides a powerful methodology in the field of environmental sciences.
@article{Rusznyak2012,
title = {Calcite Biomineralization by Bacterial Isolates from the Recently Discovered Pristine Karstic Herrenberg Cave},
author = {Anna Rusznyák and Denise M Akob and Sándor Nietzsche and Karin Eusterhues and Kai Uwe Totsche and Thomas R Neu and Torsten Frosch and Jürgen Popp and Robert Keiner and Jörn Geletneky and Lutz Katzschmann and Ernst-Detlef Schulze and Kirsten Küsel},
doi = {10.1128/AEM.06568-11},
year = {2012},
date = {2012-02-01},
urldate = {2012-02-01},
journal = {Applied and Environmental Microbiology},
volume = {78},
number = {4},
pages = {1157–1167},
abstract = {Karstic caves represent one of the most important subterranean carbon storages on Earth and provide windows into the subsurface. The recent discovery of the Herrenberg Cave, Germany, gave us the opportunity to investigate the diversity and potential role of bacteria in carbonate mineral formation. Calcite was the only mineral observed by Raman spectroscopy to precipitate as stalactites from seepage water. Bacterial cells were found on the surface and interior of stalactites by confocal laser scanning microscopy. Proteobacteria dominated the microbial communities inhabiting stalactites, representing more than 70% of total 16S rRNA gene clones. Proteobacteria formed 22 to 34% of the detected communities in fluvial sediments, and a large fraction of these bacteria were also metabolically active. A total of 9 isolates, belonging to the genera Arthrobacter , Flavobacterium , Pseudomonas , Rhodococcus , Serratia , and Stenotrophomonas , grew on alkaline carbonate-precipitating medium. Two cultures with the most intense precipitate formation, Arthrobacter sulfonivorans and Rhodococcus globerulus , grew as aggregates, produced extracellular polymeric substances (EPS), and formed mixtures of calcite, vaterite, and monohydrocalcite. R. globerulus formed idiomorphous crystals with rhombohedral morphology, whereas A. sulfonivorans formed xenomorphous globular crystals, evidence for taxon-specific crystal morphologies. The results of this study highlighted the importance of combining various techniques in order to understand the geomicrobiology of karstic caves, but further studies are needed to determine whether the mineralogical biosignatures found in nutrient-rich media can also be found in oligotrophic caves.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Karstic caves represent one of the most important subterranean carbon storages on Earth and provide windows into the subsurface. The recent discovery of the Herrenberg Cave, Germany, gave us the opportunity to investigate the diversity and potential role of bacteria in carbonate mineral formation. Calcite was the only mineral observed by Raman spectroscopy to precipitate as stalactites from seepage water. Bacterial cells were found on the surface and interior of stalactites by confocal laser scanning microscopy. Proteobacteria dominated the microbial communities inhabiting stalactites, representing more than 70% of total 16S rRNA gene clones. Proteobacteria formed 22 to 34% of the detected communities in fluvialfluvialDurch fließendes Wasser verursacht; zum Beispiel: "Fluviale Sedimente" = durch fließendes Wasser abgelagertes Material. sediments, and a large fraction of these bacteria were also metabolically active. A total of 9 isolates, belonging to the genera Arthrobacter , Flavobacterium , Pseudomonas , Rhodococcus , Serratia , and Stenotrophomonas , grew on alkaline carbonate-precipitating medium. Two cultures with the most intense precipitate formation, Arthrobacter sulfonivorans and Rhodococcus globerulus , grew as aggregates, produced extracellular polymeric substances (EPS), and formed mixtures of calcite, vaterite, and monohydrocalcite. R. globerulus formed idiomorphous crystals with rhombohedral morphology, whereas A. sulfonivorans formed xenomorphous globular crystals, evidence for taxon-specific crystal morphologies. The results of this study highlighted the importance of combining various techniques in order to understand the geomicrobiology of karstic caves, but further studies are needed to determine whether the mineralogical biosignatures found in nutrient-rich media can also be found in oligotrophic caves.
Using stalactite material and fluvial sediments from the Blessberg cave, the diversity and activity of the occuring bacteria and their formation of carbonate minerals were investigated. For this purpose, various techniques such as phylogenetic analyses, bacterial cultivation, electron microscopy, X-ray spectroscopy, confocal laser scanning microscopy, and Raman spectroscopy were used.
Bacteria were found on the surface and inside the stalactites using confocal laser scanning microscopy. Phylogenetic analyses showed that Proteobacteria were most abundant in the bacterial communities on and inside the stalactites and also in the fluvial sediments, but also other groups such as Actinobacteria or FirmicutesFirmicutesEine artenreiche Gruppe innerhalb der Bakterien. Unterscheiden sich von den Actinobakterien unter anderem durch ihren niedrigeren Gehalt an Nukleinbasen in der Bakterien-DNS.. Many of the detected bacteria have not yet been cultivated.
A total of nine new bacterial cultures were isolated from the cave sediments, growing on alkaline carbonate-precipitating medium and belonging to the bacterial genera Arthrobacter, Flavobacterium, Pseudomonas, Rhodococcus, Serratia and Stenotrophomonas. Of these, the two with the most intense precipitate formation were selected for further research: Arthrobacter sulfonivorans SCM3 and Rhodococcus globerulus SCM4. Both produced extracellular polymeric substances (EPS) and grew as cell aggregates.
Scanning electron microscopy of cell aggregates and extracellular polymeric substance (EPS) of the isolates Arthrobacter sulfonivorans SCM3 (left) and Rhodococcus globerulus SCM4 (right) (Image: Elektronenmikroskopisches Zentrum Jena, Sándor Nietzsche and Anna Rusznyak).
The carbonate minerals formed were mixtures of calcite, vaterite, and monohydrocalcite. Arthrobacter sulfonivorans SCM3 formed xenomorphic spherical crystals, and Rhodococcus globerulus SCM4 idiomorphic crystals with rhombohedral morphology.
The biomineralisation process of Arthrobacter sulfonivorans SCM3 was further investigated using a combination of Raman macro- and microspectroscopy to obtain a spatially resolved chemical representation of the different types of calcium carbonate minerals. The cell surface of Arthrobacter sulfonivorans SCM3 served as a nucleus for the biomineralisation of vaterite precipitates. These were initially spherical and then continued to grow as chemically stable, rock-forming calcite crystals with rough edges.
Scanning electron microscopy of precipitates of the isolates Arthrobacter sulfonivorans SCM3 (left) and Rhodococcus globerulus SCM4 (right) (Image: Elektronenmikroskopisches Zentrum Jena, Sándor Nietzsche and Anna Rusznyak).
@incollection{breitenbach_bbh2022,
title = {Die Bleßberghöhle – ein Glücksfall für die Klimaforschung},
author = {Sebastian F. M. Breitenbach and Norbert Marwan},
editor = {Thüringer Höhlenverein, e. V.},
year = {2022},
date = {2022-02-22},
urldate = {2022-02-22},
booktitle = {Nächster Halt: Bleßberghöhle},
address = {Suhl},
abstract = {Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.
@inproceedings{breitenbach2016,
title = {A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany},
author = {Sebastian F. M. Breitenbach and Birgit Plessen and Sarah Wenz and Jens Leonhardt and Rik Tjallingii and Denis Scholz and Klaus-Peter Jochum and Norbert Marwan},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2021/05/Breitenbach_poster_EGU_2016.pdf},
year = {2016},
date = {2016-04-01},
booktitle = {Geophysical Research Abstracts},
volume = {18},
pages = {EGU2016-14213},
abstract = {Although Holocene climate dynamics were relatively stable compared to glacial conditions, climatic changes had significant impact on ecosystems and human society on various timescales (Mayewski et al. 2004, Donges et al. 2015, Tan et al. 2015). Precious few high-resolution records on Holocene temperature and precipitation conditions in Central Europe are available (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012).
Here we present a speleothem-based reconstruction of past climate dynamics from Blessberg Cave, Thuringia, central Germany. Three calcitic stalagmites were recovered when the cave was discovered during tunneling operations in 2008. Samples BB-1, -2 and -3 were precisely dated by the 230Th/U-method, with errors between 10 and 160 years (2σ). The combined record covers large parts of the Holocene (10 – 0.4 ka BP). δ13C and δ18O were analysed at 100 μm resolution. To gain additional insights in infiltration conditions, Sr/Ca and S/Ca were measured on BB-1 and BB-3 using an Röntgenanalytik Eagle XXL μXRF scanner.
Differences to other central European records (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012) suggest complex interaction between multiple factors influencing speleothem δ18O in Blessberg Cave. Furthermore, no clear influence of the North Atlantic Oscillation on our proxies is found. However, a link across the N Atlantic realm is indicated by a centennial-scale correlation between Blessberg δ18O values and minerogenic input into lake SS1220 in Greenland over the last 5 ka (Olsen et al. 2012). In addition, recurrence analysis indicates an imprint of Atlantic Bond events on Blessberg δ18O values (Marwan et al. 2014), corroborating the suggested link with high northern latitudes. Larger runoff into the Greenland lake seems to be associated with lower δ18O, higher δ13C and S/Ca ratios, as well as lower Sr/Ca ratios in Blessberg Cave speleothems. This might be linked to lower local temperature and/or changes in precipitation seasonality. Opposing millennial scale trends with lowering S/Ca ratios and δ13C values but increasing Sr/Ca ratios calls for more than one controlling factor. Most likely, δ13C decreased through the Holocene due to afforestation, which in turn might have increased sulphate retention in the thickening soil cover (Frisia et al. 2005) and limited sulphur flux into the cave. Alternatively, marine sulfur flux could have diminished with winter wind intensities. However, additional data is required to clarify this hypothesis. A positive Sr/Ca trend through the Holocene might result from increasing prior calcite precipitation induced by a negative moisture balance in summer.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Although Holocene climate dynamics were relatively stable compared to glacial conditions, climatic changes had significant impact on ecosystems and human society on various timescales (Mayewski et al. 2004, Donges et al. 2015, Tan et al. 2015). Precious few high-resolution records on Holocene temperature and precipitation conditions in Central Europe are available (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012).
Here we present a speleothem-based reconstruction of past climate dynamics from Blessberg Cave, Thuringia, central Germany. Three calcitic stalagmites were recovered when the cave was discovered during tunneling operations in 2008. Samples BB-1, -2 and -3 were precisely dated by the 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute.-method, with errors between 10 and 160 years (2σ). The combined record covers large parts of the Holocene (10 – 0.4 ka BPka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.). δ13C and δ18O were analysed at 100 μm resolution. To gain additional insights in infiltration conditions, Sr/Ca and S/Ca were measured on BB-1 and BB-3 using an Röntgenanalytik Eagle XXL μXRF scanner.
Differences to other central European records (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012) suggest complex interaction between multiple factors influencing speleothem δ18O in Blessberg Cave. Furthermore, no clear influence of the North Atlantic Oscillation on our proxiesProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. is found. However, a link across the N Atlantic realm is indicated by a centennial-scale correlation between Blessberg δ18O values and minerogenic input into lake SS1220 in Greenland over the last 5 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr. (Olsen et al. 2012). In addition, recurrence analysis indicates an imprint of Atlantic Bond events on Blessberg δ18O values (Marwan et al. 2014), corroborating the suggested link with high northern latitudes. Larger runoff into the Greenland lake seems to be associated with lower δ18O, higher δ13C and S/Ca ratios, as well as lower Sr/Ca ratios in Blessberg Cave speleothems. This might be linked to lower local temperature and/or changes in precipitation seasonality. Opposing millennial scale trends with lowering S/Ca ratios and δ13C values but increasing Sr/Ca ratios calls for more than one controlling factor. Most likely, δ13C decreased through the Holocene due to afforestation, which in turn might have increased sulphate retention in the thickening soil cover (Frisia et al. 2005) and limited sulphur flux into the cave. Alternatively, marine sulfur flux could have diminished with winter wind intensities. However, additional data is required to clarify this hypothesis. A positive Sr/Ca trend through the Holocene might result from increasing prior calcite precipitation induced by a negative moisture balance in summer.
The first results of the geochemical analyses of the three stalagmites BB-1 to BB-3 already allow conclusions about the climatic changes of the last 14,000 years. A detailed interpretation can be found in the article Climate zone shift in Central Europe.
@misc{marwan2019lodz,
title = {Recurrence based entropies},
author = {Norbert Marwan and Kai Hauke Kraemer and Karolin Wiesner and Sebastian F. M. Breitenbach and Jens Leonhardt},
editor = {Fourth International Conference on Recent Advances in Nonlinear Mechanics, Łódz (Poland)},
year = {2019},
date = {2019-05-07},
abstract = {Many dynamical processes are considered to be of complex nature. To get a quantitative idea of the complexity, often the Shannon entropy of the value distribution of a measurement is used. Alternative entropy measures have been suggested using the recurrence plot (RP) approach. A RP is a matrix that represents the recurrences of states in the d-dimensional phase space. The RP can consist of small-scale structures, such as single points, diagonal and vertical lines, which characterize important dynamical properties of the system. Various entropy measures have been defined using different features of the RP or can be related to certain properties of the RP. Because of the different features that are used, some entropy measures represent different aspects of the analysed system and, thus, behave differently. This fact can lead to misunderstandings and difficulties in interpreting and understanding those measures. We discuss definitions, motivation and interpretation of some of those entropy measures, compare their differences and discuss some of the pitfalls when using them. },
note = {Fourth International Conference on Recent Advances in Nonlinear Mechanics, Łódz (Poland)},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Many dynamical processes are considered to be of complex nature. To get a quantitative idea of the complexity, often the Shannon entropy of the value distribution of a measurement is used. Alternative entropy measures have been suggested using the recurrence plot (RP) approach. A RP is a matrix that represents the recurrences of states in the d-dimensional phase space. The RP can consist of small-scale structures, such as single points, diagonal and vertical lines, which characterize important dynamical properties of the system. Various entropy measures have been defined using different features of the RP or can be related to certain properties of the RP. Because of the different features that are used, some entropy measures represent different aspects of the analysed system and, thus, behave differently. This fact can lead to misunderstandings and difficulties in interpreting and understanding those measures. We discuss definitions, motivation and interpretation of some of those entropy measures, compare their differences and discuss some of the pitfalls when using them.
@inproceedings{marwan2019,
title = {Recurrence based entropies},
author = {Norbert Marwan and Kai Hauke Kraemer and Karolin Wiesner and Sebastian F. M. Breitenbach and Jens Leonhardt},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2021/04/EGU2019-2817.pdf},
year = {2019},
date = {2019-04-08},
booktitle = {Geophysical Research Abstracts},
volume = {21},
pages = {EGU2019-2817},
abstract = {Dynamical processes in Earth sciences are often considered to be of complex nature. The term complexity is often used for processes that are either unpredictable (e.g. nonlinear dynamics), consist of many different components, or exhibit regime transitions (e.g. tipping points). To measure complexity, the Shannon entropy is often used.
Here we present various entropy measures that have been defined on the base of the recurrence plot. Because of the different features that are used, these entropy measures represent different aspects of the analysed system and, thus, behave differently. In the past, this fact has lead to difficulties in interpreting and understanding those measures. We summarize the definitions, the motivation and interpretation of these entropy measures, compare their differences and discuss some of the pitfalls when using them.
Finally, we illustrate their potential in an application on palaeoclimate time series. Using entropy measures, changes and transitions in the climate dynamics in the past can be identified and interpreted.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Dynamical processes in Earth sciences are often considered to be of complex nature. The term complexity is often used for processes that are either unpredictable (e.g. nonlinear dynamics), consist of many different components, or exhibit regime transitions (e.g. tipping points). To measure complexity, the Shannon entropy is often used.
Here we present various entropy measures that have been defined on the base of the recurrence plot. Because of the different features that are used, these entropy measures represent different aspects of the analysed system and, thus, behave differently. In the past, this fact has lead to difficulties in interpreting and understanding those measures. We summarize the definitions, the motivation and interpretation of these entropy measures, compare their differences and discuss some of the pitfalls when using them.
Finally, we illustrate their potential in an application on palaeoclimate time series. Using entropy measures, changes and transitions in the climate dynamics in the past can be identified and interpreted.
At PIK, among other things, new methods are being developed that, on the one hand, can be used to investigate new aspects in palaeoclimate data, but on the other hand can also cope with the difficulties usually associated with palaeoclimate analyses – such as gaps in data series, uncertainties in the dating, or irregularities in the data sampling. Although this is basic research, it is also immediately applied to interesting questions.
In this example, a method was developed to determine the regularity of certain recurring pattern in the data. The technical terms here are “recurrence” and “entropy” (a measure of disorder). Methods that look for recurring patterns are used in various disciplines, not only in the geosciences, but also in medicine, mechanical engineering, finance, and so on. Besides finding abrupt changes, they are also used for comparing different data sets or for classification (e.g. for machine learning).
The newly developed method was applied to the carbon isotopeIsotopChemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. data from BB-1 and BB-3 (for this purpose, the data from both stalagmites were combined into one long data series using a special procedure). Interestingly, there are regular differences during the influence of the maritime climate (Atlantic influence) and during the influence of the continental climate. During the Atlantic influence, the climate seems to have changed more regularly than during the dominant continental climate (this may be related to the regular change of cold events in the North Atlantic, so-called “Bond events”, or to the North Atlantic Oscillation). This could be used to extend our knowledge about the migration of the climate zone boundary, as known for the last 4,000 years (see Climate Zone Shift in central Europe), further into the past. Whenever the new measure indicates that there were more regular climate dynamics, the climate zone boundary was further east of the Bleßberg Cave.
@proceedings{klose2023poster,
title = {Timing of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and D. Scholz and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan},
editor = {Summer School on Speleothem Sciences 2023, Sao Paulo},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/klose_SummerschoolSaoPaulo2023.pdf},
year = {2023},
date = {2023-08-07},
urldate = {2023-08-07},
abstract = {The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.},
howpublished = {Poster},
note = {Summer School on Speleothem Sciences 2023, Sao Paulo},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
The last glacial period and especially Marine IsotopeIsotopChemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. stage 3 (MIS 3MIS 3"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. "MIS 3" bedeutet dabei eine kurzzeitige Warmphase (beginnend vor 57 Tausend Jahren) während der letzten Eiszeit., ca. 57 - 27 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute. dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.
Klose, J.; Scholz, D.; Weber, M.; Vonhof, H.; Plessen, B.; Breitenbach, S.; Marwan, N.
Timing and progression of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany Proceedings
@proceedings{klose2023,
title = {Timing and progression of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and D. Scholz and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan},
editor = {XXI INQUA Conference, Rome (Italy)},
year = {2023},
date = {2023-07-19},
urldate = {2023-07-19},
abstract = {Speleothems can be dated with unprecedented precision using U-series disequilibrium methods and provide numerous climate proxies, such as stable oxygen (δ18O) and carbon isotopes (δ13C) or trace elements, resulting in long, sometimes continuous climate proxy records. Therefore, speleothems have great potential for reconstruction of past climate variability during Marine Isotope Stage (MIS) 3 and precise determination of the timing and duration of Dansgaard-Oeschger (D/O) events. While first discovered in Greenland ice cores, various speleothem records around the globe provided clear evidence for the supra-regional character of the D/O events. However, MIS 3 speleothem records from Central Europe are very limited. Here we present three spleothem (flowstone) MIS 3 records from Bleßberg Cave, Germany.
All flowstones show episodic growth with distinctive, partially very thin (<2 mm) growth phases, interrupted by visible hiatuses consisting of detrital material. Precise and accurate 230Th/U dating of the individual growth phases is challenging due to potential detrital contamination from these layers. Combining different sampling and analytical techniques, we were able to date even the thinnest growth layers with very high precision, i.e., 2σ-age uncertainties of at most a few hundred years.
The timing of the growth phases aligns with several D/O events, which have not been recorded in other Central European speleothems yet. The δ18O and δ13C records of all three flowstones are highly correlated which suggests a dominant process influencing both isotope systems. Comparison with the Sr and Mg records provides evidence for a strong influence of Prior Calcite Precipitation (PCP) in the aquifer above and inside the cave on the stable isotope and trace element signals. In addition, all proxy records are interpreted as evidence for past changes in precipitation and vegetation density and document a clear trend from more humid climate during early MIS 3 (ca. 57 – 50 ka) to less humid conditions during mid and late MIS 3 (ca. 45 – 30 ka).
Our multi-proxy approach thus allows us not only to precisely determine the timing, duration, and progression of several D/O events, but also to deepen our general understanding of climate variability during MIS 3 in Central Europe.},
howpublished = {Poster},
note = {XXI INQUA Conference, Rome (Italy)},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Speleothems can be dated with unprecedented precision using U-series disequilibrium methods and provide numerous climate proxiesProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet., such as stable oxygen (δ18O) and carbon isotopes (δ13C) or trace elements, resulting in long, sometimes continuous climate proxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. records. Therefore, speleothems have great potential for reconstruction of past climate variability during Marine Isotope Stage (MISMIS"MIS" ist die Abkürzung für "marine isotope stage", übersetzt also "Isotopenstadium mariner Sedimente". Da sich beim Wechsel von Warm- zu Kaltzeiten (und umgekehrt) die Isotopenverhältnisse in den Kalkschalen kleiner Einzeller (Foraminiferen) auf dem Meeresboden ändern, werden diese zur Datierung herangezogen und lassen sich zur Eingruppierung verschiedener Klimazustände in der Vergangenheit nutzen. Die MIS werden rückwärts nummeriert (also größere Zahl = älter) und ungerade Zahlen stehen für Warmzeiten, gerade für Kaltzeiten.) 3 and precise determination of the timing and duration of Dansgaard-Oeschger (D/O) events. While first discovered in Greenland ice cores, various speleothem records around the globe provided clear evidence for the supra-regional character of the D/O events. However, MIS 3 speleothem records from Central Europe are very limited. Here we present three spleothem (flowstone) MIS 3 records from Bleßberg Cave, Germany.
All flowstones show episodic growth with distinctive, partially very thin (<2 mm) growth phases, interrupted by visible hiatuses consisting of detrital material. Precise and accurate 230Th/U dating of the individual growth phases is challenging due to potential detrital contamination from these layers. Combining different sampling and analytical techniques, we were able to date even the thinnest growth layers with very high precision, i.e., 2σ-age uncertainties of at most a few hundred years.
The timing of the growth phases aligns with several D/O events, which have not been recorded in other Central European speleothems yet. The δ18O and δ13C records of all three flowstones are highly correlated which suggests a dominant process influencing both isotope systems. Comparison with the Sr and Mg records provides evidence for a strong influence of Prior Calcite Precipitation (PCP) in the aquifer above and inside the cave on the stable isotope and trace element signals. In addition, all proxy records are interpreted as evidence for past changes in precipitation and vegetation density and document a clear trend from more humid climate during early MIS 3 (ca. 57 – 50 ka) to less humid conditions during mid and late MIS 3 (ca. 45 – 30 ka).
Our multi-proxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. approach thus allows us not only to precisely determine the timing, duration, and progression of several D/O events, but also to deepen our general understanding of climate variability during MIS 3 in Central Europe.
@proceedings{klose2022,
title = {Timing of Dansgaard-Oeschger events in Central Europe based on three precisely dated speleothems from Bleßberg Cave, Germany},
author = {J. Klose and M. Weber and H. Vonhof and B. Plessen and S. Breitenbach and N. Marwan and D. Scholz},
editor = {KR9 in Innsbruck, 2022},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2024/09/klose_KR9-Innsbruck2022.pdf},
year = {2022},
date = {2022-07-19},
urldate = {2022-07-19},
abstract = {The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.},
howpublished = {Poster},
note = {KR9 Konferenz in Innsbruck},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
The last glacial period and especially Marine Isotope stage 3 (MIS 3, ca. 57 - 27 ka) was characterized by various climate oscillations (i.e., rapid increases in temperature, followed by a gradual cooling, the Dansgaard-Oeschger (D/O) events), which were first discovered in Greenland ice cores. Although their causes are still not fully understood, clear evidence for their supra-regional character was found in various climate records around the globe. However, European speleothem samples, which grew during MIS 3, are limited and mainly restricted to alpine regions, where glacier meltwater enabled speleothem growth, and to south/south-western parts of Europe characterised by a generally warmer climate. This led to the opinion that it was too cold and/or too dry in central Europe for speleothem growth. Here we present three speleothem (flowstone) records from Bleßberg Cave, Germany, which grew during MIS 3.
All flowstones show episodical growth patterns with distinctive, thin growth phases. Potential contamination deriving form detrital material deposited during hiatuses between individual growth phases, open-system behaviour around the hiatuses and the limited thickness of the growth layers are the biggest challenges during sampling for 230Th/U dating. By combination of different sampling techniques (i.e., laser ablation and micro-milling) in addition to the common approach of handheld drilling and due to the relatively high 238U concentration of the samples (approx. 0.4 – 1 µg/g), we were able to date even the thinnest growth layers (< 2 mm) of the Bleßberg flowstones with a very high precision (i.e., with 2σ-age uncertainties of a few hundred years or even lower).
The timing of the growth phases of the Bleßberg flowstones correlates with several D/O events recorded in the Greenland ice cores. This proves that at least some phases of MIS 3 had favourable climate conditions for speleothem growth in Central Europe. In addition, the analysis of the stable oxygen and carbon isotopes (δ18O and δ13C) for all three flowstones revealed several D/O events, which have not been recorded in any other speleothem from central Europe so far. This will enhance our understanding of climate variability during MIS 3 and specific D/O events in central Europe.
@incollection{breitenbach_bbh2022,
title = {Die Bleßberghöhle – ein Glücksfall für die Klimaforschung},
author = {Sebastian F. M. Breitenbach and Norbert Marwan},
editor = {Thüringer Höhlenverein, e. V.},
year = {2022},
date = {2022-02-22},
urldate = {2022-02-22},
booktitle = {Nächster Halt: Bleßberghöhle},
address = {Suhl},
abstract = {Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.
@inproceedings{marwan2014,
title = {Recurrence properties as signatures for abrupt climate change},
author = {Norbert Marwan and Sebastian F. M. Breitenbach and Birgit Plessen and Denis Scholz and Jens Leonhardt
},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2021/04/EGU2014-8893.pdf},
year = {2014},
date = {2014-04-01},
booktitle = {Geophysical Research Abstracts},
volume = {16},
pages = {EGU2014-8893},
abstract = { The study of recurrence properties of dynamical systems has been shown to be very successful in characterising typical dynamical behaviour, finding regime transitions, or detecting couplings and synchronisations, even for short, noisy, and nonstationary data, as typical in Earth Sciences. Recurrence plots and their quantifications are powerful techniques for the investigation of recurrence and increasingly attract attention in recent years. We demonstrate the potential of the newly introduced extension of recurrence plot analysis by complex network measures for the detection of abrupt dynamical changes. This method is applied on a Holocene palaeoclimate data set from Central Europe derived from a stalagmite from Blessberg Cave, Thuringia, Germany. The stalagmite δ18O proxy record covers the middle to late Holocene (6000-400 years BP). Dating uncertainties are considered by an ensemble approach derived from the COPRA framework. Characteristic changes in the recurrence properties reflecting regular dynamics coincide well with the occurrence of the Bond events 1, 2, and 3. During Bond events the Central European climate variability appears more regular. The analysis presented here examplifies the potency of quantitative recurrence methods in detecting climatic events, which otherwise remain hidden in the raw proxy time series. },
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The study of recurrence properties of dynamical systems has been shown to be very successful in characterising typical dynamical behaviour, finding regime transitions, or detecting couplings and synchronisations, even for short, noisy, and nonstationary data, as typical in Earth Sciences. Recurrence plots and their quantifications are powerful techniques for the investigation of recurrence and increasingly attract attention in recent years. We demonstrate the potential of the newly introduced extension of recurrence plot analysis by complex network measures for the detection of abrupt dynamical changes. This method is applied on a Holocene palaeoclimate data set from Central Europe derived from a stalagmite from Blessberg Cave, Thuringia, Germany. The stalagmite δ18O proxy record covers the middle to late Holocene (6000-400 years BPka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr.). Dating uncertainties are considered by an ensemble approach derived from the COPRA framework. Characteristic changes in the recurrence properties reflecting regular dynamics coincide well with the occurrence of the Bond events 1, 2, and 3. During Bond events the Central European climate variability appears more regular. The analysis presented here examplifies the potency of quantitative recurrence methods in detecting climatic events, which otherwise remain hidden in the raw proxy time series.
Among other things, new methods are being developed at PIK that, on the one hand, investigate new aspects in palaeoclimate data, but also cope with the difficulties usually associated with palaeoclimate analyses – such as gaps in the data, age uncertainties, or irregularities in the data sampling. While this is basic research, it is also immediately applied to interesting research questions.
One focus is the development and application of methods that specifically investigate recurring patterns. These methods are very successful for finding abrupt changes, but also for comparing different data sets, e.g., to detect mutual influences.
In one of our first analyses of the three stalagmites BB-1 to BB-3, we had looked at the oxygen isotopes of BB-1 with recurrence based methods. Thereby we had explicitly considered dating uncertainties. Due to the dating uncertainties there are small shifts of the time series along the x-axis. Therefore, within the uncertainties, different realizations of the course of the measured oxygen isotopes are possible.
Oxygen isotopes of BB-1. Due to the dating uncertainties, there are several possibilities when changes in this climate archive happened. The stalagmite grew from about 6,000 years ago to about 400 years ago.
The recurrence patterns are examined with a special analysis tool, the so-called “recurrence plot”. This can be used to plot times when similar states have occurred. The patterns seen in such a recurrence plot have a deeper meaning and can be further analyzed and quantified to find changes in the dynamics of the underlying process.
Recurrence plot of one realization of the measured oxygen isotopes in BB-1.
The numerical analysis of recurrence plots yields various results that shed light on different aspects of climate dynamics. Two such results are briefly presented here: on the one hand, the complexity of climate variability (“transitivityTransitivityEin Maß aus der Netzwerktheorie, welches quantifiziert, wie stark sich Zustände zu kleinen Gruppen zusammenfinden.”) and, on the other hand, how well such a climate signal would be predictable (“determinismDeterminismEin Maß aus der Wiederkehr-Analyse, welches beschreibt, wie gut sich die Veränderung eines Systems vorhersagen läßt.”). Both results show a general tendency towards greater complexity and lower predictability for younger ages. However, they also show short-lived increases to better predictability for certain time points, namely about 4,200, 2,800, and 1,400 years ago. It was precisely at these times that short-lived and rapid glaciations occurred in the North Atlantic, the so-called “Bond events.” Moreover, there are variations in the complexity of the climate signal (“transitivity”), but these variations are within the range of uncertainty (confidence interval), so we cannot really interpret them.
Quantitative analysis of recurrence patterns in oxygen isotope measurements of BB-1.
@incollection{breitenbach_bbh2022,
title = {Die Bleßberghöhle – ein Glücksfall für die Klimaforschung},
author = {Sebastian F. M. Breitenbach and Norbert Marwan},
editor = {Thüringer Höhlenverein, e. V.},
year = {2022},
date = {2022-02-22},
urldate = {2022-02-22},
booktitle = {Nächster Halt: Bleßberghöhle},
address = {Suhl},
abstract = {Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
Höhlen stellen generell für die Wissenschaft ein wertvolles Archiv dar, aus dem vielfältige und interessante Erkenntnisse gewonnen werden können. So gehören sie inzwischen auch zu den bedeutendsten Klimaarchiven auf dem Festland (See- und Meeressedimente stellen andere wichtige Archive dar). Solange die Höhlensedimente und Sinter ungestört bleiben, können hydrologische und klimatische Bedingungen detailliert aufgezeichnet werden. Die Bleßberghöhle ist in diesem Zusammenhang ein ausgesprochener Glücksfall, da sie über viele Jahrtausende komplett verschlossen war und so vor äußeren Störungen bewahrt wurde. Sie ist in vielen Abschnitten mit verschiedensten Sinterformen geschmückt. Für die Rekonstruktion regionaler Klimaänderungen sind vor allem die Stalagmiten geeignet. Die wissenschaftliche Bearbeitung des aus der Bleßberghöhle gesammelten Materials ist ein langwieriger Prozess und noch lange nicht abgeschlossen. Zum gegenwärtigen Zeitpunkt können aber bereits erste interessante Aussagen gemacht werden, auf die wir hier nach einem kurzen allgemeinen Einblick in verschiedene Aspekte der Paläoklimaforschung eingehen wollen.
@article{breitenbach2019,
title = {Holocene interaction of maritime and continental climate in Central Europe: New speleothem evidence from Central Germany},
author = {Sebastian F. M. Breitenbach and Birgit Plessen and Sarah Waltgenbach and Rik Tjallingii and Jens Leonhardt and Klaus-Peter Jochum and Hanno Meyer and Bedartha Goswami and Norbert Marwan and Denis Scholz},
doi = {10.1016/j.gloplacha.2019.03.007},
year = {2019},
date = {2019-00-00},
journal = {Global and Planetary Change},
volume = {176},
pages = {144–161},
abstract = {Central European climate is strongly influenced by North Atlantic (Westerlies) and Siberian High circulation patterns, which govern precipitation and temperature dynamics and induce heterogeneous climatic conditions, with distinct boundaries between climate zones. These climate boundaries are not stationary and shift geographically, depending on long-term atmospheric conditions. So far, little is known about past shifts of these climate boundaries and the local to regional environmental response prior to the instrumental era.
High resolution multi-proxy data (stable oxygen and carbon isotope ratios, S/Ca and Sr/Ca) from two Holocene stalagmites from Bleßberg Cave (Thuringia) are used here to differentiate local and pan-regional environmental and climatic conditions Central Germany through the Holocene. Carbon isotope and S/Ca and Sr/Ca ratios inform us on local Holocene environmental changes in and around the cave, while δ18O (when combined with independent records) serves as proxy for (pan-)regional atmospheric conditions.
The stable carbon isotope record suggests repeated changes in vegetation density (open vs. dense forest), and increasing forest cover in the late Holocene. Concurrently, decreasing S/Ca values indicate more effective sulfur retention in better developed soils, with a stabilization in the mid-Holocene. This goes in hand with changes in effective summer infiltration, reflected in the Sr/Ca profile. Highest Sr/Ca values between 4 ka and 1 ka BP indicate intensified prior calcite precipitation resulting from reduced effective moisture supply.
The region of Bleßberg Cave is sensitive to shifts of the boundary between maritime (Cfb) and continental (Dfb) climate and ideally suited to reconstruct past meridional shifts of this divide. We combined the Bleßberg Cave δ18O time series with δ18O data from Bunker Cave (western Germany) and a North Atlantic Oscillation (NAO) record from lake SS1220 (SW Greenland) to reconstruct the mean position of the Cfb-Dfb climate boundary. We further estimate the dynamic interplay of the North Atlantic Oscillation and the Siberian High and their influence on Central European climate. Repeated shifts of the Cfb-Dfb boundary over the last 4000 years might explain previously observed discrepancies between proxy records from Europe. Detailed correlation analyses reveal multi-centennial scale alternations of maritime and continental climate and, concurrently, waning and waxing influences of Siberian High and NAO on Central Europe.},
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pubstate = {published},
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Central European climate is strongly influenced by North Atlantic (Westerlies) and Siberian High circulation patterns, which govern precipitation and temperature dynamics and induce heterogeneous climatic conditions, with distinct boundaries between climate zones. These climate boundaries are not stationary and shift geographically, depending on long-term atmospheric conditions. So far, little is known about past shifts of these climate boundaries and the local to regional environmental response prior to the instrumental era.
High resolution multi-proxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. data (stable oxygen and carbon isotopeIsotopChemische Elemente können aus verschieden aufgebauten Atomen gebildet sein. Die Anzahl Protonen im Atomkern ist zwar dabei gleich, aber die Anzahl der Neutronen kann variieren. Man spricht dann von Isotopen, deren Massen kleine, aber messbare Unterschiede aufweisen. Der Atomkern des Sauerstoffs besteht z. B. aus 8 Protonen und in der Regel aus 8 Neutronen. Es gibt aber auch Sauerstoff, dessen Kerne aus 8 Protonen und 9 oder 10 Neutronen bestehen (neben selteneren, instabilen Sauerstoffisotopen). Um das zu kennzeichnen, gibt man zusätzlich zum chemischen Symbol noch die Massenzahl (Summe aus Protonen und Neutronen) an, also 16O, 17O oder 18O. Die unterschiedlichen Isotope verhalten sich zwar chemisch identisch, physikalisch aber - aufgrund ihres unterschiedlichen Gewichtes - leicht unterschiedlich. Damit stellen sie äusserst wertvolle Marker dar, die uns wichtige Hinweise zur Änderung des Klimas, der Umgebungsvegetation, Bodenaktivität und vielem mehr geben. ratios, S/Ca and Sr/Ca) from two Holocene stalagmites from Bleßberg Cave (Thuringia) are used here to differentiate local and pan-regional environmental and climatic conditions Central Germany through the Holocene. Carbon isotope and S/Ca and Sr/Ca ratios inform us on local Holocene environmental changes in and around the cave, while δ18O (when combined with independent records) serves as proxyProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. for (pan-)regional atmospheric conditions.
The stable carbon isotope record suggests repeated changes in vegetation density (open vs. dense forest), and increasing forest cover in the late Holocene. Concurrently, decreasing S/Ca values indicate more effective sulfur retention in better developed soils, with a stabilization in the mid-Holocene. This goes in hand with changes in effective summer infiltration, reflected in the Sr/Ca profile. Highest Sr/Ca values between 4 kaka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr. and 1 ka BPka BPMit "ka BP" sind "Tausend Jahre vor 1950" gemeint. Das "BP" steht für "before present", was in der Paläoklima-Wissenschaft als 1950 festgelegt wurde. "11.000 ka BP" bedeuted also 11 Tausend Jahre vor 1950, oder unter Verwendung unseres gewohnten Kalenders: 9050 v. Chr. indicate intensified prior calcite precipitation resulting from reduced effective moisture supply.
The region of Bleßberg Cave is sensitive to shifts of the boundary between maritime (Cfb) and continental (Dfb) climate and ideally suited to reconstruct past meridional shifts of this divide. We combined the Bleßberg Cave δ18O time series with δ18O data from Bunker Cave (western Germany) and a North Atlantic Oscillation (NAO) record from lake SS1220 (SW Greenland) to reconstruct the mean position of the Cfb-Dfb climate boundary. We further estimate the dynamic interplay of the North Atlantic Oscillation and the Siberian High and their influence on Central European climate. Repeated shifts of the Cfb-Dfb boundary over the last 4000 years might explain previously observed discrepancies between proxy records from Europe. Detailed correlation analyses reveal multi-centennial scale alternations of maritime and continental climate and, concurrently, waning and waxing influences of Siberian High and NAO on Central Europe.
@inproceedings{breitenbach2016,
title = {A multi-proxy reconstruction of Holocene climate change from Blessberg Cave, Germany},
author = {Sebastian F. M. Breitenbach and Birgit Plessen and Sarah Wenz and Jens Leonhardt and Rik Tjallingii and Denis Scholz and Klaus-Peter Jochum and Norbert Marwan},
url = {https://bbh.pik-potsdam.de/wp-content/uploads/2021/05/Breitenbach_poster_EGU_2016.pdf},
year = {2016},
date = {2016-04-01},
booktitle = {Geophysical Research Abstracts},
volume = {18},
pages = {EGU2016-14213},
abstract = {Although Holocene climate dynamics were relatively stable compared to glacial conditions, climatic changes had significant impact on ecosystems and human society on various timescales (Mayewski et al. 2004, Donges et al. 2015, Tan et al. 2015). Precious few high-resolution records on Holocene temperature and precipitation conditions in Central Europe are available (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012).
Here we present a speleothem-based reconstruction of past climate dynamics from Blessberg Cave, Thuringia, central Germany. Three calcitic stalagmites were recovered when the cave was discovered during tunneling operations in 2008. Samples BB-1, -2 and -3 were precisely dated by the 230Th/U-method, with errors between 10 and 160 years (2σ). The combined record covers large parts of the Holocene (10 – 0.4 ka BP). δ13C and δ18O were analysed at 100 μm resolution. To gain additional insights in infiltration conditions, Sr/Ca and S/Ca were measured on BB-1 and BB-3 using an Röntgenanalytik Eagle XXL μXRF scanner.
Differences to other central European records (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012) suggest complex interaction between multiple factors influencing speleothem δ18O in Blessberg Cave. Furthermore, no clear influence of the North Atlantic Oscillation on our proxies is found. However, a link across the N Atlantic realm is indicated by a centennial-scale correlation between Blessberg δ18O values and minerogenic input into lake SS1220 in Greenland over the last 5 ka (Olsen et al. 2012). In addition, recurrence analysis indicates an imprint of Atlantic Bond events on Blessberg δ18O values (Marwan et al. 2014), corroborating the suggested link with high northern latitudes. Larger runoff into the Greenland lake seems to be associated with lower δ18O, higher δ13C and S/Ca ratios, as well as lower Sr/Ca ratios in Blessberg Cave speleothems. This might be linked to lower local temperature and/or changes in precipitation seasonality. Opposing millennial scale trends with lowering S/Ca ratios and δ13C values but increasing Sr/Ca ratios calls for more than one controlling factor. Most likely, δ13C decreased through the Holocene due to afforestation, which in turn might have increased sulphate retention in the thickening soil cover (Frisia et al. 2005) and limited sulphur flux into the cave. Alternatively, marine sulfur flux could have diminished with winter wind intensities. However, additional data is required to clarify this hypothesis. A positive Sr/Ca trend through the Holocene might result from increasing prior calcite precipitation induced by a negative moisture balance in summer.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Although Holocene climate dynamics were relatively stable compared to glacial conditions, climatic changes had significant impact on ecosystems and human society on various timescales (Mayewski et al. 2004, Donges et al. 2015, Tan et al. 2015). Precious few high-resolution records on Holocene temperature and precipitation conditions in Central Europe are available (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012).
Here we present a speleothem-based reconstruction of past climate dynamics from Blessberg Cave, Thuringia, central Germany. Three calcitic stalagmites were recovered when the cave was discovered during tunneling operations in 2008. Samples BB-1, -2 and -3 were precisely dated by the 230Th/UU/Th-DatierungDie U/Th-Datierung ist eine sehr präzise radiometrische Altersbestimmung auf Basis der Uran-Thorium-Zerfallsreihe. Das Uran zerfällt mit bekannten Halbwertszeiten (245.500 Jahre) zum Tochterelement Thorium. Stalagmiten bauen bei ihrem Wachstum (fast) nur das wasserlösliche Uran ein, während das schlecht bewegliche Thorium zum größten Teil im Boden und Epikarst über der Höhle verbleibt. Das kann man nutzen, um die Zeit zu berechnen, die seit der Ausfällung der untersuchten Karbonatprobe vergangen ist. Moderne massenspektrometrische Verfahren erlauben Altersbestimmungen mit der U/Th-Methode bis zu 700.000 Jahren vor Heute.-method, with errors between 10 and 160 years (2σ). The combined record covers large parts of the Holocene (10 – 0.4 ka BP). δ13C and δ18O were analysed at 100 μm resolution. To gain additional insights in infiltration conditions, Sr/Ca and S/Ca were measured on BB-1 and BB-3 using an Röntgenanalytik Eagle XXL μXRF scanner.
Differences to other central European records (e.g., von Grafenstein et al. 1999, Fohlmeister et al. 2012) suggest complex interaction between multiple factors influencing speleothem δ18O in Blessberg Cave. Furthermore, no clear influence of the North Atlantic Oscillation on our proxiesProxyUmwelt- und Klimainformationen aus der Vergangenheit sind nicht direkt verfügbar, weil niemand da war, der diese messen und aufzeichnen konnte. Daher ist man darauf angewiesen, diese Informationen indirekt aus anderen Informationen abzuleiten, wie z. B. Baumringe, das Verhältnis von Sauerstoffisotopen, Spurenelementen, Mächtigkeit von Sedimentschichten usw. Diese Art von Daten nennt man Proxies, was aus dem englischen stammt und „Stellvertreter“ bedeutet. is found. However, a link across the N Atlantic realm is indicated by a centennial-scale correlation between Blessberg δ18O values and minerogenic input into lake SS1220 in Greenland over the last 5 ka (Olsen et al. 2012). In addition, recurrence analysis indicates an imprint of Atlantic Bond events on Blessberg δ18O values (Marwan et al. 2014), corroborating the suggested link with high northern latitudes. Larger runoff into the Greenland lake seems to be associated with lower δ18O, higher δ13C and S/Ca ratios, as well as lower Sr/Ca ratios in Blessberg Cave speleothems. This might be linked to lower local temperature and/or changes in precipitation seasonality. Opposing millennial scale trends with lowering S/Ca ratios and δ13C values but increasing Sr/Ca ratios calls for more than one controlling factor. Most likely, δ13C decreased through the Holocene due to afforestation, which in turn might have increased sulphate retention in the thickening soil cover (Frisia et al. 2005) and limited sulphur flux into the cave. Alternatively, marine sulfur flux could have diminished with winter wind intensities. However, additional data is required to clarify this hypothesis. A positive Sr/Ca trend through the Holocene might result from increasing prior calcite precipitation induced by a negative moisture balance in summer.
The three stalagmites BB-1 to BB-3 were geochemically investigated by GFZ Potsdam, Ruhr-Uni Bochum, PIK Potsdam, Uni Mainz and Northumbria University.
The dating was done at the University of Mainz. Stalagmite BB-1 grew 5,600 to 600 years ago, BB-2 6,200 to 3,700 years ago, and BB-3 (although the shortest) 11,200 to 5,300 years ago. At GFZ, carbon and oxygen isotopes (δ13C and δ18O) were measured in over 1,000 samples in BB-1, and about 400 and 540 samples each in BB-2 and BB-3. In parallel, the distribution of various elements was measured by X-ray analysis. Age modelling and statistical analysis were carried out at Ruhr-Uni Bochum, PIK Potsdam and Northumbria University.
In the age models of stalagmites BB-1 and BB-3, abrupt changes from slow to fast growth are evident at about 5,900 BC and from fast to more slow growth at about 2,600 BC.
Age models of stalagmites BB-1 and BB-3. Changes in growth rates at around 6,200 BC and between 5,900 and 2,600 BC can clearly be seen, for which climatic changes are responsible.
The temporal changes in isotope ratios were compared with palaeoclimate data from the Bunker Cave in North Rhine-Westphalia and from Greenland.
Isotope ratios in stalagmites BB-1 and BB-3 (combined). The longer-term trends probably reflect a change in solar influence. The short-term climate cooling around 6,200 BC is clearly visible in the isotope ratios. The abrupt drop in δ18O values around 900 to 1,200 AD coincides with the Medieval Warm Period.
This comparison allows an estimation of the spatial distribution of the influence of the maritime, humid and warm Atlantic climate in Central Europe. The Blessberg cave is located at the border between the influence of the Atlantic climate and the continental, drier and colder climate from the east. From the alternation between stronger similarities and greater differences in the regional climate at the Blessberg Cave and the Bunker Cave it can be determined when the climate zone boundary was east or west of the Bleßberg Cave, i.e. when the Atlantic, wetter and warmer climate and when the colder and drier continental climate prevailed over the Bleßberg Cave. This analysis could be carried out back to about 4,000 years ago (i.e. about 2050 BC). Before this time, due to the lack of data from Greenland, it is not yet possible to make conclusions regarding the location of the climate zone boundary, but at least around this time the Bleßberg Cave was probably under the influence of the Atlantic climate. Around 1850 BC it then changed to a continental climate (in the late Aunjetitz culture, known from the Nebra sky disc). Between 950 and 850 BC, the Atlantic influence became more dominant again (towards the end of the Urnfield Culture).
Shift of the climate zone boundary (dashed) to the east with hypothetical course (dotted) at the time of the Urnfield Culture (BU – Bunker Cave, BBH – Blessberg Cave).
