Collaborative Research: Contrasts in the Petrologic Chemical, and Isotopic Evolution of Two Archean Mid-crustal Environments: Processes Controlling Crustal Growth

该提案寻求资金支持对中地壳（大约125-25公里）岩石中记录的大陆地壳生长和发展进行岩石学、结构学、化学和同位素研究。中地壳是一个动态环境，地球物质在其中进行机械和化学循环。上地壳岩石可能通过构造作用被搬运到中地壳水平；地壳的幼年添加物可能来自地幔；流体通量可能引发熔化，可能产生沙诺克石，或浸出LIL元素；中间地壳的熔化可以通过无蒸汽熔化提取大量的熔体。在蒙大拿州西南部麦迪逊山脉北部的两个不同的太古宙地壳岩石块中，已经发现了许多这些过程的产物。我们对这段太古代大陆地壳的综合研究将使我们对大陆地壳生长和发育的地球化学过程有更全面的了解，以及对控制怀俄明州北部地壳演化的构造和岩浆旋回的具体情况有更全面的了解。

This proposal seeks funds to support a collaborative petrologic, structural, chemical, and isotopic investigation of the growth and development of continental crust as recorded in rocks of the middle crust (roughly 125-25 km). The middle crust is a dynamic environment through which Earth materials are cycled both mechanically and chemically. Supracrustal rocks may be transported to mid-crustal levels through tectonic processes; juvenile additions to the crust may be emplaced from the mantle; fluid fluxes may initiate melting, possibly to produce charnockites, or leach LIL elements; melting in the middle crust may extract large volumes of melt through vapor-absent melting. Artifacts of many of these processes have been recognized in two distinct blocks of Archean crustal rocks in the northern Madison Range, SW Montana. Our integrated study of this segment of Archean continental crust will lead to a more comprehensive understanding of the geochemical processes that contribute to the growth and development of continental crust, as well as to the specifics of the tectonic and magmatic cycles controlling crustal evolution in the northern Wyoming Province.