Paläoklimatische Indikatoren und zyklostratigraphische Untersuchungen der Sedimente des tropischen Lake Towuti's anhand geophysikalischer Bohrlochmessdaten
Physik des Erdkörpers
Zusammenfassung der Projektergebnisse
Lake Towuti. We generated the first nearly complete age-depth model for the lacustrine facies of Lake Towuti and examined the potential of geophysical downhole logging for time estimation and lithological description. This study provides insights into the sedimentary history of the basin between radiometric ages derived from dating a tephra layer (797 ka) and 14C-ages (45 ka) in the cores. We derived an age-depth model that spans from late marine isotope stage MIS 23 to late MIS 6 (903 ± 11 ka to 131 ± 67 ka). Ohrid – Age-depth model from downhole data. In this study, we present an approach to construct age-depth models based on integrating downhole logging and seismic survey data when there are no samples available for dating. First, we interpret seismic data and correlate downhole logging data from three sites - DEEP, Pestani and Cerava - to the LR04 benthic stack. We crosscheck the resulting age-depth models using cyclostratigraphic methods. In the second step, we construct an artificial lithological log based on cluster analysis using the physical properties of the sediments and integrate it with the age-depth model. This allows an initial interpretation of the sedimentological history at Cerava and Pestani. Ohrid – Half-precession (HP). Next to a connection of HP cycles to interglacials, we see a more pronounced HP signal in the younger part of several proxy records. Although the HP signal is present in all of the investigated sites, we observe a more pronounced HP signal in the southeast compared to records from the north. The latter is consistent with the assumption that HP is an equatorial signal and can be transmitted northward via various pathways. The appearance of HP signals in mid- and high-latitude records can thus be an indicator for the intensity of the mechanisms driving these pathways. The African Monsoon probably plays a major role in this context, as its magnitude directly influences the climate systems of the Mediterranean and Southern Europe.
Projektbezogene Publikationen (Auswahl)
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(2016): The Towuti Drilling Project: paleoenvironments, biological evolution, and geomicrobiology of a tropical Pacific lake. - Scientific Drilling 21, 29-40
Russell, J.M., Bijaksana, S., Vogel, H., Melles, M., Kallmeyer, J., Ariztegui, D., Crowe, S., Fajar, S., Hafidz, A., Haffner, D., Hasberg, A., Ivory, S., Kelly, C., King, J., Kirana, K., Morlock, M., Noren A., O'grady, R., Ordonez, L., Stevenson, J., Von Rintelen, T., Vuillemin, A, Watkinson, I., Wattrus, N., Wicaksono, S., Wonik, T., Bauer, K., Deino, A., Friese, A., Henny, C., Imran, Marwoto, R., Ngkoimani, L.O., Nomosatryo, S., Safiuddin, L.O., Simister, R., Tamuntuan, G.
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(2019): Mediterranean winter rainfall in phase with African monsoon during past 1.36 million years. – Nature
Wagner, B., Vogel, H., Francke, A., Friedrich, T., Donders, T., Lacey, J., Leng, M., Regattieri, E., Sadori, L., Wilke, T., Zanchetta, G., Albrecht, C., Bertini, A., Combourieu-Nebout, N., Cvetkoska, A., Giaccio, B., Grazhdani, A., Hauffe, T., Holtvoeth, J., Joannin, S., Jovanovska, E. Just, J., Kouli, K., Kousis, I., Koutsodendris, A., Krastel, S., Leicher, N., Levkov, Z., Lindhorst, K., Masi, A., Melles, M., Mercuri, A.M., Nomade, S., Nowaczyk, N., Panagiotopoulos, K., Peyron, O., Reed, J.M., Sagnotti, L., Sinopoli, G., Stelbrink, B., Sulpizio, R., Timmermann, A., Tofilovska, S., Torri, P., Wagner-Cremer, F., Wonik, T. & Zhang, X.
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(2021): Cyclostratigraphy and paleoenvironmental inference from downhole logging of sediments in tropical Lake Towuti, Indonesia. - Journal of Paleolimnology, 65: 377–392
Ulfers, A., Hesse, K., Zeeden, C., Russell, J. M., Vogel, H., Bijaksana, S. & Wonik, T.
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(2022): Borehole logging and seismic data from Lake Ohrid (North Macedonia/Albania) as a basis for age-depth modelling over the last one million years. - Quaternary Science Reviews; 276: 107295
Ulfers, A., Zeeden, C., Wagner, B., Krastel, S., Buness, H. & Wonik, T.
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(2022): Half precession signals in Lake Ohrid (Balkan) and their spatio-temporal relations to climate records from the European realm. – Quarternary Science Reviews; 280: 107413
Ulfers, A., Zeeden, C., Voigt, S., Sardar Abadi, M. & Wonik, T.
