Mantle Composition as a Function of Crustal Tectonics, Southwestern U.S.

美国西南部地幔成分与地壳构造函数的关系

• 批准号: 8708307
• 负责人: Michael Roden
• 金额: $ 2.7万
• 依托单位: University of Georgia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1990-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8708307&HistoricalAwards=false
• 关键词: Mantle; Composition; Function; Crustal; Tectonics

This is a study of the geochemistryof mantle-derived, spinel peridotite xenoliths from localities in the Basin and Range Province and the adjacent Colorado Plateau, as well as the transition zone between the two provinces. The heart of the study is the anlysis and modelling of the REE and Sr and Nd isotopic compositions of clinopyroxene seperated from the bulk peridotites, but xenolith population systematics and mineral composition will be investigated and will be particularly important in choosing representative samples for study. In addition to standard analytical techniques, secondary ion mass spectrometry will be utilized to measure relative REE abundances in single cpx grains. Present-day mantle composition beneath the two tectonic provinces will be characterized and for each locality a model will be developed. This will include observed heterogeneity (or homogeneity) and where possible, the inferred age and nature of fractionation events. Ultimately models for all localities will be integrated to provide a regional model for the systematic variation of mantle composition as it relates to large-scale crustal tectonism.

这是一项幔源尖晶石的地球化学研究这是一项幔源尖晶石的地球化学研究 海盆和山脉橄榄岩捕虏体 省和邻近的科罗拉多高原，以及 两省之间的过渡区。 的核心 稀土元素和Sr、Nd的分析与模拟 单斜辉石的同位素组成 橄榄岩，但捕虏体人口系统学和矿物 组合物将被调查，并将特别是 重要的是选择有代表性的样本进行研究。 在 除了标准分析技术，二次离子质量 光谱法将用于测量相对稀土元素丰度 在单个CPX颗粒中。 两个构造省下的现今地幔成分 将被描述，并为每个地方的模型将被 开发 这将包括观察到的异质性（或同质性） 并在可能的情况下，推断年龄和分馏性质 事件 最终将整合所有地方的模型 提供一个区域模型， 地幔成分与大尺度地壳 构造作用