Collaborative Research: (GRGC) High Resolution Glacial Geologic and Palynologic Records of the Last Deglaciation in the Tropical Andes

合作研究：（GRGC）热带安第斯山脉末次冰消期的高分辨率冰川地质和孢粉学记录

• 批准号: 9422423
• 负责人: Kenneth Young
• 金额: $ 5.27万
• 依托单位: University of Maryland Baltimore County
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-01 至 1998-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9422423&HistoricalAwards=false
• 关键词: Collaborative; Research; GRGC; Resolution; Glacial

9422423 Young The primary objective of the proposed project is to obtain continuous, high-resolution, AMS 14C datable proxy records of glaciation and vegetation change from lacustrine sediment cores that span the last deglaciation and Holocene from four regions in the tropical Andes where evidence for abrupt climatic reversals during the last glacial-to-interglacial transition have already been documented. The PIs seek to improve not only the chronology of late-glacial climatic oscillations in the tropical Andes but also to improve the basis for interpreting the sedimentologic and palynologic records. Specifically, the PIs propose: i) to couple glacial geology and glacial-lacustrine sedimentology to provide estimates for the timing , rate, and magnitude of changes in glacier equilibrium -line altitudes during the last deglaciation, ii) to couple modern vegetation studies with palynological analyses of sediment cores from the western Amazon Basin to estimate the timing of and paleoclimatic factors responsible for the abrupt changes in vegetation that marked the last glacial-to-interglacial transition in this region, iii) to collaborate with Ecuadorian geologists to date and characterize geochemically conspicuous tephra units that were deposited during the last deglaciation so that these important isochrons may be used to correlate precisely among proxy records of paleoclimate preserved in sediment and ice cores from different sites in the tropical Andes, and iv) to provide closer age constraints for specific moraines, which, based on both preliminary and published radiocarbon ages, were deposited at about the same time as the YD and H1 Events.

9422423 Young 拟议项目的主要目标是从热带安第斯山脉四个地区跨越最后一次冰消期和全新世的湖泊沉积岩芯中获取连续、高分辨率、AMS 14C 可数据化的冰川作用和植被变化代理记录，这些地区已经记录了末次冰期到间冰期过渡期间气候突变的证据。 PI不仅致力于改善热带安第斯山脉晚冰期气候振荡的年代学，而且还改善解释沉积学和孢粉学记录的基础。 具体而言，PI建议：i）将冰川地质学和冰川湖沉积学结合起来，以估计末次冰消期冰川平衡线高度变化的时间、速率和幅度，ii）将现代植被研究与亚马逊盆地西部沉积物岩芯的孢粉学分析结合起来，以估计导致植被突然变化的时间和古气候因素 标志着该地区最后一次冰期到间冰期的转变，iii) 与厄瓜多尔地质学家合作，对上次冰消期期间沉积的地球化学上显着的碎石单元进行测定和表征，以便这些重要的等时线可用于精确关联热带安第斯山脉不同地点沉积物和冰芯中保存的古气候代理记录，以及 iv) 为特定冰碛提供了更接近的年龄限制，根据初步和公布的放射性碳年龄，这些冰碛大约与 YD 和 H1 事件同时沉积。