Elongate Plutons in a Large-Volume Magmatic Arc, Central Sierra Nevada, California: Do they Represent Dike-Fed Chambers?

加利福尼亚州内华达山脉中部大体积岩浆弧中的拉长岩体：它们是否代表岩浆岩室？

• 批准号: 9404697
• 负责人: Othmar Tobisch
• 金额: $ 16.07万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-10-01 至 1998-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9404697&HistoricalAwards=false
• 关键词: Elongate; Plutons; Large; Volume; Magmatic

9404697 Tobisch Very large granitic bodies are a common feature in the development of magmatic arcs and convergent continental margins, however despite considerable study the mechanisms of ascent, assembly and emplacement of granitic magma within mid-to-upper crustal levels are still controversial. This project will test a possible solution involving whether elongate, large-volume Early- Late Cretaceous plutons typical of the Sierra Nevada, California, represent dike-fed magma chambers rather than diapirs. the work will involve establishing the geometry and kinematics of magma flow in the pluton and model the assembly and emplacement, while constraining the ascent mechanism from the flow dynamic and observed wall rock structures the main tools will be anisotropy of magnetic susceptibility (AMS) image analysis of magmatic fabrics and field observation. Results are expected to provide sufficient documentation to help resolve the magma room problem and help develop a tectonic model of the Sierra Nevada that more accurately treats the magmatic activity.

小行星9404697 超大型花岗岩体是岩浆弧和会聚型大陆边缘发育过程中的一个共同特征，然而，尽管有大量的研究，但花岗质岩浆在中上地壳水平的上升、聚集和侵位机制仍存在争议。 本项目将测试一种可能的解决方案，涉及加州内华达州山脉典型的细长、大体积早白垩世-晚白垩世岩体是否代表岩脉供给的岩浆房而不是底辟。 这项工作将包括建立岩体中岩浆流动的几何学和运动学，并模拟岩浆的聚集和侵位，同时从流动动力学和观察到的围岩结构中限制上升机制，主要工具将是岩浆组构的磁化率各向异性（AMS）图像分析和野外观察。 预计结果将提供足够的文件，以帮助解决岩浆房的问题，并帮助开发一个构造模型的内华达州，更准确地对待岩浆活动。