Magnetic Susceptibility Variations in Cave Sediments from the Moravian Karst, Czech Republic: A Record of Environmental Change

点击翻译按钮获取中文摘要

97-05718 Diehl Variations in mineral magnetic properties of iron from marine, lake, and wind blown (loess) deposits have been shown to reflect changes in Earth's orbit, climate, and human activity. Cave sediments have gone almost unnoticed in these environmental magnetic studies and, in many instances, these sediments contain a rich history of early man. The Czech Geological Survey and Michigan Technological University have been studying the cave deposits of the Moravian Karst over the last several years to reconstruct the Pleistocene/Holocene paleoclimate record in which these sediments were deposited. This proposed research concentrates on discovering the nature of environmental and/or anthropogenic processes that may be causing variations in magnetic susceptibility and other mileral magnetic parameters in two sequences of cave sediments. The first sequence is from the floodwater deposits of Spiralka Cave where the magnetic susceptibility variations recorded in the upper part of this section appear to track the 10-year averaged winter temperature anomalies determined from direct temperature measurements (over the last 200 years) at the Prague-Klementinum Observatory. The second sequence consists of loess deposits from the entrance facies of Kulna Cave, a well-studied archeological site. Preliminary work indicates magnetic susceptibility highs are perhaps controlled by increased erosion of a pedogenic source material during cold intervals rather than by in-situ pedogenic enhancement during warm intervals. This work also has important implications for tying the cave stratigraphy of Central Europe (and its record of man) to changes in the global ice volume as Kulna Cave is the type locality for cave deposits in Central Europe. ***