Rare Earth Elements and Nd Isotopes in Hydrothermal Metalliferous Sediments: Pleistocene and Cenozoic Paleoceanography

热液含金属沉积物中的稀土元素和 Nd 同位素：更新世和新生代古海洋学

• 批准号: 0137350
• 负责人: Robert Sherrell
• 金额: $ 18.32万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0137350&HistoricalAwards=false
• 关键词: Rare; Earth; Elements; Nd; Isotopes

In this study, the PIs will test and develop a new paleoclimate proxy- Rare Earth Element (REE) abundances of carbonate sediments that contain metalliferous sediment originating from hydrothermal plumes. In combination, the PIs will use Nd isotope values (?Nd) as a proxy to help unravel differences in weathering rates and sources from variations in seawater REE abundances due to other causes. The short residence times of the REE (1-4 Ka) mean that potentially, these proxies could provide high resolution data. Preliminary data show that metalliferous sediment records bottom water REE patterns and that the REE patterns are virtually identical for the Atlantic and Pacific. The entire REE pattern is reflected in differences in Nd/Er. Preliminary data for a core for the last 135 Ka indicate that Nd/Er and ???O are well correlated, showing good potential for the proxy. Additional preliminary data for a longer period (last 28Ma) show interesting patterns and large changes in ?Nd and Nd/Er for this period, again arguing that these combined proxies have potential to identify changing weathering inputs to the ocean. In order to further evaluate this proxy, the PIs will analyze hydrothermal plume material from additional hydrothermal vents in the northern and southern EPR, carry out lab experiments of REE uptake in vitro, calibrate the Nd/Er proxy using Holocene core tops from SEPR cores, evaluate possible diagenetic effects on the preservation of the proxy signals using cores with known and diverse diagenetic histories, and explore the behavior of both proxies on Ma to 10 Ka time scales for large climatic variations in the Oligocene and Miocene.

在这项研究中，PIS将测试和开发新的古气候较稀土元素（REE）丰富的碳酸盐沉积物，其中包含来自水热羽流的金属沉积物。结合使用，PI将使用ND同位素值（？nd）作为代理，以帮助揭示风化速率的差异和由于其他原因而导致的海水REE丰度变化的来源。 REE的短停留时间（1-4 ka）意味着，这些代理可能会提供高分辨率数据。初步数据表明，金属沉积物记录了底部水REE模式，而REE模式对于大西洋和太平洋来说实际上是相同的。整个REE模式反映在ND/ER的差异中。最后135 ka的核心的初步数据表明ND/ER和??? O良好相关，显示出良好的代理潜力。在此期间，更长的时间（最后28mA）的其他初步数据显示了有趣的模式和大量变化，并再次争辩说，这些组合的代理有潜力可以识别出对海洋的不断变化的风化输入。 In order to further evaluate this proxy, the PIs will analyze hydrothermal plume material from additional hydrothermal vents in the northern and southern EPR, carry out lab experiments of REE uptake in vitro, calibrate the Nd/Er proxy using Holocene core tops from SEPR cores, evaluate possible diagenetic effects on the preservation of the proxy signals using cores with known and diverse diagenetic histories, and explore the behavior在MA到10 ka时间尺度上的两个代理，用于渐新世和中新世的较大气候变化。