A Detailed Chemical and Isotopic Investigation of Mesozoic Atlantic MORB

中生代大西洋MORB（NSF OCE 96 -17676）的详细化学和同位素研究 这是一个建议，进行详细的化学和Sr，Nd和Pb同位素调查中生代MORB从中央和北大西洋。这些钻探地点中的大多数玄武岩以前都没有被详细研究过，只有两个钻探地点的样品有同位素数据。该项目的目的是扩大我们目前的调查全球白垩纪中期的地幔柱岩浆活动对海洋上地幔的组成的影响。 中生代太平洋MORB的数据表明，太平洋上地幔经历了快速和广泛的高度不相容的元素和放射性锶富集后不久，开始在白垩纪中期的喷发高原和septut-building火山作用约120马。我们希望限制的幅度和地理范围的上地幔富集的“脉冲”，因为它将提供重要的信息广泛的白垩纪板内火山作用的性质，并将使我们能够测试模型的火山事件的起源，在核心的相互作用下地幔或下地幔上地幔边界。

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.