Collaborative Research: Combined Electron/Ion Microprobe Study of the Composition of the Deep Continental LithosphereBeneath the Colorado Plateau and Adjoining Regions

该项目将集中在科罗拉多高原和毗邻的 推断的元古代橄榄岩根 延伸到大约80-100公里的深度， 大陆岩石圈断裂 丰富的样品上 地幔存在于科罗拉多高原内外的火山岩中， 捕虏体中的某些矿物相记录了 岩石圈的组成历史。 微量元素 矿物相的丰度（REE、Ti、Zr、Hf、Sr）将用于 推断岩石圈整体成分的变化 纵向和横向，所涉及的阶段的性质， 最近的岩浆或交代事件，任何痕迹的性质 元素分馏（例如，REE/HFSE）与这些一致 事件，以及这些事件的时间从分区建模 数据区. 主要的分析工具将是离子和 微量和主要元素原位分析用电子微探针 元素

This project will focus on the Colorado Plateau and adjoining regions where an inferred Proterozoic-aged, peridotite root extends to a depth of approximately 80-100 km and is surrounded by rifted continental lithosphere. Abundant samples of the upper mantle occur in volcanic rocks on and off the Colorado Plateau, and some mineral phases in these xenoliths record the recent compositional history of the lithosphere. Trace element abundances (REE,Ti,Zr,Hf,Sr) of mineral phases will be used to deduce the variation in the bulk composition of the lithosphere vertically and laterally, the nature of the phases involved in recent magmatic or metasomatic events, the nature of any trace element fractionations (e.g., REE/HFSE) coincident with these events, and the timing of these events from modelling of zoning profiles. Principal analytical tools will be the ion and electron microprobes for in situ analysis of trace and major elements.