Using Mg-Paleothermometry to Deconvolute the Marine Oxygen Isotope Record

使用 Mg-古温计对海洋氧同位素记录进行解卷积

• 批准号: 9819254
• 负责人: David Lea
• 金额: --
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819254&HistoricalAwards=false
• 关键词: Using; Mg; Paleothermometry; Deconvolute; Marine

This project will explore the utility of Mg/Ca in foraminiferal calcite as a tracer of water temperature. If Mg/Ca has a consistent correlation with water temperature and is not subject to complications such as physiologic fractionation or post-depositional diagenesis, it can be used in conjunction with 18 O/16 O to estimate sea surface temperature and mean ocean composition as a function of ice volume, allowing the determination of two important variables in the geologic past. Paired analyses of Mg/Ca and 18 O/16 O will be done on various sample sets to test for effects of (1) species-specific fractionation, (2) growth-rate, and (3) dissolution. Studies will incorporate analyses in at least two cores from the tropical Pacific over glacial/interglacial time scales to test applicaiton of the method. 13 C/12 C data generated by the same analyses will be used to evaluate the record of past ocean alkalinity and partial pressure of CO 2, using calibrations previously established in the laboratory.

该项目将探索有孔虫方解石中Mg/Ca作为水温示踪剂的用途。如果Mg/Ca与水温具有一致的相关性，并且不受生理分馏或沉积后成岩作用等复杂因素的影响，则可以将其与18 O/16 O结合使用，以估计作为冰量函数的海面温度和平均海洋组成，从而确定地质历史中的两个重要变量。将对不同的样品组进行Mg/Ca和18 O/16 O的配对分析，以测试（1）物种特异性分馏，（2）生长速率和（3）溶解的影响。研究将包括至少两个来自热带太平洋的冰/间冰期时间尺度的岩心分析，以测试该方法的适用性。由相同分析产生的13 C/12 C数据将用于评估过去海洋碱度和二氧化碳分压的记录，使用先前在实验室建立的校准。