Pb Isotopes in the Southern Ocean: A Study of Pb Systematics and Continental Weathering During the Eocene/Oligocene Transition

南大洋的铅同位素：始新世/渐新世过渡期间的铅系统学和大陆风化研究

• 批准号: 0926474
• 负责人: Ellen Martin
• 金额: $ 29.58万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926474&HistoricalAwards=false
• 关键词: Pb; Isotopes; Southern; Ocean; Study

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This award supports a research effort to construct deep water Pb isotopic records across the "Greenhouse-icehouse" (Eocene/Oligocene boundary) transition using six Ocean Drilling Program sites located in the Southern Ocean. The project goals are to expand understanding of: 1) seawater Pb systematics in this region, and 2) continental weathering processes during the evolution of the Antarctic cryosphere. In terms of systematics, records extracted from bulk sediments will allow study of the stratification of the water column with respect to Pb, providing information about the input and transfer of Pb to deep waters. In addition, the PI will evaluate whether Southern Ocean inputs are dominated by Pb advected into the basin with water masses from the Atlantic and Pacific, or by Pb derived internally from local weathering. A comparison between seawater and detrital Pb isotopes will also be used to evaluate the intensity of chemical versus mechanical weathering during growth of the Antarctic Ice Sheet, with a detailed evaluation across a weathering pulse identified by Nd isotopes. Provenance studies based on crossplots of seawater Pb isotopes will yield information about source regions and input sites. This award will also support graduate and undergraduate research experiences, outreach activities within the local community, and material for classroom discussions and exercises.

该奖项根据 2009 年《美国复苏和再投资法案》（公法 111-5）提供资助。该奖项支持利用六种方法构建跨越“温室-冰室”（始新世/渐新世边界）过渡的深水铅同位素记录的研究工作海洋钻探计划地点位于南大洋。该项目的目标是扩大对以下方面的了解：1）该地区的海水铅系统，2）南极冰冻圈演化过程中的大陆风化过程。 在系统学方面，从大量沉积物中提取的记录将有助于研究水体中铅的分层，提供有关铅向深水输入和转移的信息。 此外，PI 将评估南大洋的输入是否主要由来自大西洋和太平洋的水团平流进入盆地的 Pb 主导，还是由当地风化作用内部产生的 Pb 主导。海水和碎屑铅同位素之间的比较也将用于评估南极冰盖生长过程中化学风化与机械风化的强度，并对由 Nd 同位素识别的风化脉冲进行详细评估。 基于海水铅同位素交会图的来源研究将产生有关源区和输入地点的信息。 该奖项还将支持研究生和本科生的研究经验、当地社区内的外展活动以及课堂讨论和练习的材料。