In-Situ Pb Isotope Analysis of Olivine-Hosted Melt Inclusions in MORB

MORB 中橄榄石熔体包裹体的原位 Pb 同位素分析

• 批准号: 0083255
• 负责人: Nobumichi Shimizu
• 金额: $ 16.74万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0083255&HistoricalAwards=false
• 关键词: Situ; Pb; Isotope; Analysis; Olivine

Recommended project for Pb isotopic analysis of olivine-hosted melt inclusions from mid-ocean ridge baslats (MORBs) from a geochemically anomalous segment of the Mid-Atlantic Ridge (MAR), with a goal of examining the origin, amplitude, and scale lengths of chemical heterogeneity of the MORB source mantle. Analysis will occur by an innovative, new technique using the ion microprobe to analyze melt inculsions that are 40 um or large in size, examining melt inclusion isotopic heterogeneity that occurs within individual olivine crystals, within individual samples, and within an individual ridge segment. About 50 melt inclusions will be analyzed from a number of individual lavas to examine within-flow heterogeneity. The samples to be analyzed are from 12-16 degrees N on the MAR, where a range of PB isotopic composition occurs in host samples, and include individual samples showing great diversity in their melt inclusions compositions. This data will be used to test and calibrate models of mantle melting and melt transport associated with slow spreading ridges such as the MAR.

中大西洋脊（MAR）地球化学异常段中海脊玄武岩（MORB）中橄榄石含矿熔融包裹体Pb同位素分析推荐项目，目的是研究MORB源地幔化学非均质性的起源、幅度和尺度长度。分析将采用一种创新的新技术，使用离子微探针分析40微米或更大尺寸的熔体内含物，检查单个橄榄石晶体、单个样品和单个脊段内的熔体内含物同位素异质性。大约50个熔体包裹体将从一些单独的熔岩中分析，以检查流内的非均质性。待分析的样品分布在MAR上12-16°N范围内，宿主样品中存在一定范围的PB同位素组成，并且包括单个样品，其熔体包裹体组成具有很大的多样性。这些数据将用于测试和校准与缓慢扩展脊（如MAR）相关的地幔熔化和熔体运输模型。