The Quaternary Record of Lake-Level Oscillation and Climate Change: Lake Issyk-Kul, Kyrgyzstan, Central Asia

摘要ATM-9632967 Rasmussen，Kenneth A. 作者声明：Ian G. 史密森学会名称：湖泊水位振荡和气候变化的第四纪记录：中亚吉尔吉斯斯坦伊塞克湖 位于前苏联吉尔吉斯斯坦共和国的伊塞克湖是世界上第五深的湖（668米）。 伊塞克湖位于海拔1600米的亚洲大陆，位于冬季西伯利亚高压和夏季西南印度低压之间，即使由于这些主要大气要素的位置或强度的气候变化而导致水分和/或温度状况发生微妙变化，也会影响湖泊水位的变化。盆地湖泊具有丰富的碳酸盐沉积物和丰富的大规模的自然历史，并正在进行湖平面的变化。 在过去的70年里，现代湖泊的水位下降了3米，有证据表明，在任何可能的人类干预之前，甚至还有更大的振荡。 初步的野外工作显示，古海岸线记录在无机和微生物成因的沿海硬地-这些提供了一个晚全新世湖平面位置的日期代理。 该奖项支持以下研究：（1）近岸碳酸盐岩和晚全新世海滩沉积，以及（2）深盆沉积和古湖沼记录。 通过现代类比，将确立残余微生物岩的古环境意义。 通过岩相学技术，水泥矿物学分析，以检测盐度变化，方解石水泥的初步稳定同位素分析，以评估其作为水文制度代理的效用，将建立生活和遗迹微生物岩的起源，生长和最近的环境历史。

Abstract ATM-9632967 Rasmussen, Kenneth A. Macintyre, Ian G. Smithsonian Institution Title: The Quaternary Record of Lake-Level Oscillation and Climate Change: Lake Issyk-Kul, Kyrgyzstan, Central Asia Lake Issyk-Kui in the former Soviet Republic of Kyrgyzstan is the fifth deepest lake in the world (668 meters). Issyk-Kul is located 1600m above sea level in the Asian landmass, and is positioned between the winter Siberian High and the summer Southwest Indian Low-even subtle changes in moisture and/or temperature regime due to climate shifts in the position or intensity of these major atmospheric elements should effect changes in lake-level Issyk-Kul is a closed-basin lake with abundant carbonate sediments and a rich natural history of large-scale, and ongoing lake-level change. Modern lake level has fallen 3 meters in the last 70 years and evidence suggests even larger oscillations long before any possible human intervention. Preliminary fieldwork revealed that paleo- shorelines are recorded in coastal hardgrounds of inorganic and microbialitic origin- these provide a dateable proxy for Late Holocene lake level positions. This award supports a investigation of: (1) nearshore carbonates and Late Holocene beach deposits, and (2) the deep-basin sedimentary and paleolimnological record. Paleoenivronmental significance of the relic microbialites will be established through modern analogues. Origin, growth, and recent environmental history of the living and relic microbialites will be established through petrographic techniques, mineralogic analysis of cements to detect salinity shifts, and preliminary stable isotopes analysis of calcite cements to assess their utility as proxies for hydrologic regime.