Collaborative Research: Origins of the Ontong Java Plateau, SW Pacific: A Stratigraphic and Geochemical Study of Exposed Plateau Basement in the Solomon Islands, Part 2

合作研究：西南太平洋翁通爪哇高原的起源：所罗门群岛裸露高原基底的地层学和地球化学研究，第 2 部分

• 批准号: 9628252
• 负责人: Clive Neal
• 金额: $ 8.94万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9628252&HistoricalAwards=false
• 关键词: Collaborative; Research; Origins; Ontong; Java

9628252 Neal This project is for a continuation of research into the origin and evolution of the world's largest oceanic plateau, the Ontong Java Plateau (OJP) in the SW Pacific. Previously funded study, complementing work on submarine OJP lavas drilled by the Ocean Drilling Program (ODP), focused on plateau basement sections on Santa Isabel and Malaita, Solomon Islands. This research involves the following tasks. FIELDWORK: Detailed, stratigraphically controlled sampling in south and southeastern Makira, in what is expected to be the deepest part of the Makiran section. 40Ar-39Ar DATING: Dating of samples from throughout the Makiran section is required to determine if 90 Ma and/or 122 Ma lavas are present, and to establish the significance and thickness of the 34 Ma and 64 Ma events. GEOCHEMISTRY AND PETROGRAPHY: Systematic major and trace element, and Nd-Pb-Sr isotopic analyses are required to define Makiran geochemical stratigraphy; in particular, the geochemical variation of OJP-type lavas with depth, the nature and stratigraphic extent of the broadly MORB-like basalts, and the nature and causes of intercalation of the two types. PLATINUM GROUP ELEMENTS (PGEs): Results from previous study show that lavas from Malaita and ODP drill sites are enriched in the siderophile elements W and Mo, and may indicate a core-mantle boundary origin for the OJP's mantle source. Further evaluation of this hypotheses requires determination of abundances of the ultra-siderophilic PGEs for a subset of OJP lavas.

9628252 NEAL这个项目是为了继续研究世界上最大的海洋高原，Sw Pacific的Ontong Java高原（OJP）的起源和演变。 先前资助的研究，补充了海洋钻探计划（ODP）钻探潜艇OJP熔岩的工作，该研究重点是所罗门群岛的圣塔伊莎贝尔和玛拉塔的高原地下室。 这项研究涉及以下任务。 实地调查：详细的，在麦加拉南部和东南部的地层控制的采样，预计将是Makiran部分最深的部分。 40AR-39AR日期：需要整个Makiran部分的样品日期，以确定是否存在90 MA和/或122 MA熔岩，并确定34 MA和64 MA事件的显着性和厚度。 地球化学和岩石学：系统的主要和痕量元素和痕量元素，以及ND-PB-SR同位素分析需要定义Makiran地球化学地层；特别是，OJP型熔岩的地球化学变化，深度，宽阔的玄武岩的性质和地层范围，以及两种类型的插入的性质和原因。 白金组元素（PGES）：先前研究的结果表明，来自Malaita和ODP钻头的熔岩富集在Siderophile Elements W和MO中，并且可能表明OJP掩体源的核心掩体边界起源。 对该假设的进一步评估需要确定OJP熔岩子集的超副细胞PGE的丰度。