Quaternary Paleoclimate Record from Tropical South America: Lake Titicaca

杜克大学Dunbar， Robert B. William Marsh Rice大学Fritz， Sherilyn C. LeHigh大学Seltzer， Geoffrey Syracuse大学题目：来自南美洲的的的喀喀湖的第四纪古气候记录需要一个来自南美洲热带的长而连续的古气候记录来回答几个持久而重要的问题。该奖项通过对秘鲁和玻利维亚北部高原的的的喀喀湖深盆地进行取样，支持恢复这一记录。通过对一系列短柱状小柱状岩心的初步分析，表明该湖的沉积物适合于气候重建。先前的研究揭示了全新世和更新世湖泊水位的大幅波动，这意味着有效湿度（可能还有温度）已经剧烈波动。中分辨率、深穿透地震反射剖面将有助于一系列长岩心的定位。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；有机磷、无机磷和生物硅的测定；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.