Quaternary Paleoclimatic Record from Tropical South America: Lake Titicaca

摘要ATM-9616972贝克，保罗·A·杜克大学ATM-9708257邓巴，罗伯特·B·威廉·马什·赖斯大学ATM-9708256弗里茨，谢里琳·利哈伊大学ATM-9708258塞尔策，杰弗里·锡拉丘兹大学标题：南美洲第四纪古气候记录：喀喀湖热带南美洲长期而连续的古气候记录需要回答几个长期而重要的问题。该奖项通过在秘鲁和玻利维亚北部高原的喀喀湖深盆地取芯，支持恢复这样的记录。通过对一系列短小活塞式岩心的初步分析，证明该湖沉积适合于气候重建。以前的研究表明，全新世和更新世湖泊水位出现了大幅波动，这意味着有效水分(可能还有温度)发生了剧烈波动。一系列长岩心的定位将得到中分辨率、更深穿透的地震反射剖面的帮助。随后将对岩心进行年代学(AMS放射性碳)、沉积学、物理性质、地球化学、有机碳和纤维素的稳定同位素分析；有机和无机磷、生物硅的测定；以及古生物群(介形虫和硅藻物种组成)的分析，这一记录将使我们能够详细研究高纬度气候的热带强迫的时间和机制，以及高原和亚马逊盆地的气候之间的联系。

Abstract ATM-9616972 Baker, Paul A. Duke University ATM-9708257 Dunbar, Robert B. William Marsh Rice University ATM-9708256 Fritz, Sherilyn C. LeHigh University ATM-9708258 Seltzer, Geoffrey Syracuse University Title: Quaternary Paleoclimate Record from South America: Lake Titicaca A long and continuous paleoclimate record from tropical South America is needed to answer several persistent and important questions. This award supports the recovery of such a record by coring the deep basin of Lake Titicaca on the northern Altiplano of Peru and Bolivia. Through the preliminary analysis of a series of short, mini-piston cores, it is demonstrated that the sediments of the lake are suitable for climatic reconstruction. Previous studies revealed large-amplitude fluctuations of lake level in the Holocene and Pleistocene, implying that effective moisture (and probably temperature) has dramatically fluctuated. Siting of a series of long cores will be aided by medium-resolution, deeper penetration seismic reflection profiling. The cores will be subsequently analyzed for chronology (AMS radiocarbon), sedimentology, physical properties, geochemistry, stable isotopic analysis of organic carbon and cellulose; determination of organic and inorganic phosphorous, and biogenic silica; and paleobiota (ostracode and diatom species compositions), This record will allow us to examine in detail the timing and mechanisms of tropical forcing of high-latitude climate, as well as the linkage between the climate of the Altiplano and the Amazon basin.