Quaternary Paleoclimatic Record From Tropical South America: Drilling the Salar de Uyuni, Bolivia

ATM-9820165 Fritz，SherilynUniversity of Nebraska-Lincoln标题：南美洲热带第四纪古气候记录：钻探乌尤尼岩心该奖项支持一个钻探乌尤尼岩心的项目，以恢复一个300米长的岩心，代表了大约0.5年的历史。将使用多代理方法对岩心进行分析，以重建高原的气候(有效湿度和温度)时间序列。测年方法有14C法、Ar/Ar法和U/Th法。对沉积学、流体包裹体岩相学、稳定同位素和元素地球化学以及古生物群(硅藻)的详细研究将构成气候重建的基础。将讨论以下主要问题：(1)南美洲热带地区晚更新世气候变化的性质是什么？(2)南美洲热带冰期是湿的还是干的？(3)陆地热带气候变化是否与米兰科维奇强迫一致，它们与高纬度变化是否同步？是什么气候机制(如大气水汽浓度的变化)导致了这些变化？(4)热带亚轨道尺度气候变化的主要频率是什么？陆地热带的这些变化与高纬度的变化是同步的吗？是什么气候机制导致了这些古气候特征？

AbstractATM-9820165Fritz, SherilynUniversity of Nebraska-LincolnTitle: Quaternary Paleoclimatic Record from Tropical South America: Drilling the Salar de UyuniThis award supports a project to drill the Salar de Uyuni in order to recover a 300-meter long core, representing a history of about 0.5Myr. The core will be analyzed using a multi-proxy approach to reconstruct a climatological (effective moisture and temperature) time series of the Altiplano. Dating will be done by 14C, Ar/Ar, and U/Th methods. Detailed studies of the sedimentology, fluid inclusion petrography, stable isotopic and elemental geochemistry, and paleobiota (diatoms) will form the basis for the climatological reconstruction. The following majors questions will be addressed: (1) What was the nature of late Pleistocene climate variability in tropical South America ? (2) Was tropical South America wet or dry during glacial stages? (3) Are terrestrial tropical climate changes consistent with Milankovitch forcing and are they synchronous with high latitude changes? What climatic mechanisms (e.g. changes in the concentration of atmospheric water vapor) are responsible for these changes? (4) What are the dominant frequencies of suborbital-scale climatic changes in the tropics and are these variations in the terrestrial tropics synchronous with those at higher latitudes? What climatic mechanisms are responsible for these paleoclimatic characteristics?