Climate Change in the Northern and Western Black Sea Region Based on U-Th isochron Dated Stalagmites from the Crimean Peninsula and Eastern Romania
I propose to use stalagmites from karst caves in Ukraine (Crimean Peninsula) and Eastern Romania (Dobrogea Mountains) for precise and accurately dated palaeoclimatic reconstruction in the Black Sea region since MIS 3. The main objective is to obtain a reliable chronology of climate change on the basis of detailed U-Th dating, using an isochron approach to accurately correct for detrital 230Th contamination. This technique will be made available for other projects of the Collaborative Research Center (CRC). The scientific focus is on the reconstruction of rapid climate change across globally recognised events with stable C and O isotope ratios and trace elements. These proxies usually reflect temperature, moisture supply and carbon cycling in the soil. Potential causality between environmental change and human evolution and the spread of agriculture will be investigated in close collaboration with projects B1 and F1.
Several times in the history of human kind, the northern and western Black sea region played an important, very particular role in the dynamics and migrations of ancient populations. The F4 project will address the potential role of climate change in these observations by using speleothems as palaeoclimatic archives. In the last five years, speleothems have become an important source for palaeoclimatic reconstruction. Their best benefit lies in the highly accurate and precise chronology achievable by U-Th dating, particularly when using an isochron approach to correct for detrital 230Th contamination. Speleothems also allow the analysis for some of the most successfully applied palaeoclimatic proxies, the stable isotopes of C and O. These provide information about moisture supply, moisture source, soil activity and plant cover. Within this project, speleothems will be used for the reconstruction of the Late Pleistocene to Holocene climate record since the marine isotope stage 3 (MIS 3) in the northern and western Black Sea region. This region turned out to be one of the key areas regarding possible interrelations between population dynamics, human mobility and climate change (see also project B1). During MIS 3, the crucial time for the population change between Neanderthals and modern humans, it hosted (in Crimea and adjacent areas) one of the backwaters of late Neanderthal survival, possibly as late as 30,000 ka. During the last glacial maximum, the northern and western Black Sea area saw growing hunter-gatherer populations, at the very time when central Europe was widely abandoned. Later, during the early Holocene, it became one of the transmission pathways (through Romania) of European neolithisation (see also project F1).
Consequently, in project F4, the use of speleothems (stalagmites) from two karst regions in Crimea (Tchatyr Dag) and Eastern Romania (Dobrogea Mountains) for precise and accurate palaeoclimatic reconstruction for the Black Sea region since MIS 3 is proposed. The chronology will be based on detailed U-Th dating, using an isochron approach to accurately correct for detrital 230Th contamination. This technique will be available for other CRC projects. Stable C and O isotope ratios, together with trace element analysis, will be analysed. They usually reflect temperature, moisture supply and soil activity. On the basis of these proxies, potential causality between environmental change and the evolution of Modern Man will be investigated.
All scientific work of this proposal will be conducted by a PhD candidate under the supervision of the PI. The project comprises two field campaigns into the Dobrogea Mountains and the Tchatyr Dag during the first year. Stalagmites will be retrieved according to the outcome of an initial reconnaissance study prior to the CRC (first half of 2009), where small samples will be drilled from stalagmites in-situ for subsequent U-Th age screening. Stable C and O isotopes and trace elements will be utilised as climatic proxies. Scientific work during the first year will focus on the material from Dobrogea and in the second year on Tschatyr Dag. A second field campaign into Romania is scheduled during the project’s second year. By early in the third year, the PhD candidate is anticipated to conclude all analytical work. The remainder of the third year will be spent on discussion within the CRC, synthesis of results with respect to climate impact on cultural evolution and publication of results.