A Detailed Chemical and Isotopic Investigation of Mesozoic Atlantic MORB

中生代大西洋 MORB 的详细化学和同位素研究

• 批准号: 9617676
• 负责人: Paterno Castillo
• 金额: $ 14万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-15 至 2000-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9617676&HistoricalAwards=false
• 关键词: Detailed; Chemical; Isotopic; Investigation; Mesozoic

A DETAILED CHEMICAL AND ISOTOPIC INVESTIGATION OF MESOZOIC ATLANTIC MORB (NSF OCE96-17676) This is a proposal to conduct a detailed chemical and Sr, Nd and Pb isotopic investigation of Mesozoic MORB from the central and North Atlantic. Basalts from most of these drill sites have not been investigated in detail before, and samples from only two drill sites have any isotopic data. The objective of the project is to expand our current investigation of the effects of global mid-Cretaceous plume magmatism on the composition of the oceanic upper mantle. Data for Mesozoic Pacific MORB suggest that the Pacific upper mantle underwent rapid and widespread enrichment in highly incompatible elements and radiogenic Sr soon after the initiation of effusive plateau- and seamount-building volcanism in the mid-Cretaceous around 120 Ma. We wish to constrain the magnitude and geographic extent of this upper mantle enrichment "pulse", as it will provide critical information on the nature of the widespread Cretaceous intraplate volcanism, and will allow us to test models relating the origin of the volcanic event to interactions at the core-lower mantle or lower mantle-upper mantle boundaries.

中生代大西洋 MORB 的详细化学和同位素调查 (NSF OCE96-17676) 这是一项对中生代大西洋 MORB 进行详细化学和 Sr、Nd 和 Pb 同位素调查的提案。大多数这些钻探地点的玄武岩以前都没有经过详细调查，只有两个钻探地点的样本具有同位素数据。该项目的目标是扩大我们目前对全球白垩纪中期地幔柱岩浆作用对海洋上地幔成分影响的研究。 中生代太平洋 MORB 的数据表明，在白垩纪中期 120 Ma 左右喷发的高原和海山火山活动开始后不久，太平洋上地幔经历了高度不相容元素和放射性 Sr 的快速和广泛富集。我们希望限制这种上地幔富集“脉冲”的幅度和地理范围，因为它将提供有关广泛的白垩纪板内火山活动性质的关键信息，并使我们能够测试将火山事件的起源与地核-下地幔或下地幔-上地幔边界相互作用相关的模型。