Geochemical and Textural Consequences of Compaction

压实的地球化学和结构后果

• 批准号: 9725394
• 负责人: William Meurer
• 金额: $ 10.47万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725394&HistoricalAwards=false
• 关键词: Geochemical; Textural; Consequences; Compaction

9725394 Meurer Crystals that nucleate and grow in magma chambers can separate from the liquid and accumulate on the chamber floor. This process, termed fractional crystallization, is of fundamental importance in the study of igneous rocks. Rocks formed by the accumulation of crystals are called cumulates and provide a record of how fractional crystallization proceeds. Cumulates host significant economic minerals deposits including platinum group metals, chromium ore, and copper-and nickel-sulfides. The bulk of the ocean crust and most of the moon are also made of cumulates. During slow cooling, accumulated crystals can undergo compaction driven by the density contrast between the crystals and interstitial liquid. Compaction can expel liquid from the crystal pile or simply redistribute it within it. During compaction, recrystallization may take place changing the shape of grains and allowing them to pack more efficiently. Modern computer technology now allows quantitative textural study of cumulates. This study will provide the first large scale analysis that combines both chemical and textural data. By documenting the consequences of compaction we will further our understanding of fractional crystallization and hence the formation of cumulates and the mineral resources they host on the Earth and moon.

9725394在岩浆房中成核和生长的Meurer晶体可以从液体中分离出来并聚集在岩浆房的底部。 这个过程称为分离结晶，在火成岩的研究中具有根本的重要性。 由晶体堆积形成的岩石称为堆积岩，它提供了分离结晶过程的记录。 堆积物承载着重要的经济矿藏，包括铂族金属、铬矿、铜和镍硫化物。 海洋地壳的大部分和月球的大部分也是由堆积物组成的。 在缓慢冷却期间，积聚的晶体可以经历由晶体和间隙液体之间的密度对比驱动的压实。 压实可以将液体从晶体堆中排出或简单地将其重新分布在其中。在压实过程中，重结晶可以发生，从而改变晶粒的形状并使其更有效地堆积。 现代计算机技术使堆积物的定量结构研究成为可能。 这项研究将提供第一个结合化学和纹理数据的大规模分析。 通过记录压实的后果，我们将进一步了解结晶分离，从而形成累积和矿物资源，他们在地球和月球上的主机。