http://www.sciencedirect.com/science/article/pii/S1674987112000631 |
| |
| Authors: | ,
Jacques LRTouret
,
Jan Marten Huizeng |
| |
| Institution: | 1. Musée de Minéralogie, MINES ParisTech, 75272 Paris Cedex 06, France
2. Department of Geology, School of Environmental Sciences and Development, North-West University, Private Bag X6001, Potchefstroom2520, South Africa |
| |
| Abstract: | Charnockites sensu lato (charnockite-enderbite series) are lower crustal felsic rocks typically characterised by the presence of anhydrous minerals including orthopyroxene and garnet. They either represent dry (H2O-poor) felsic magmas that are emplaced in the lower crust or granitic intrusions that have been dehydrated during a subsequent granulite facies metamorphic event. In the first case, post-magmatic high-temperature recrystallisation may result in widespread metamorphic granulite microstructures, superimposed or replacing the magmatic microstructures. Despite recrystallisation, magmatic remnants may still be found, notably in the form of melt-related microstructures such as melt inclusions. For both magmatic charnockites and dehydrated granites, subsequent fluid-mineral interaction at intergrain boundaries during retrogradation are documented by microstructures including K-feldspar microveins and myrmekites. They indicate that a large quantity of low-H2O activity salt-rich brines, were present (together with CO2 under immiscible conditions) in the lower crust. |
| |
| Keywords: | Charnockite Petrology Microstructure Melt inclusions |
| 本文献已被 CNKI 维普 万方数据 ScienceDirect 等数据库收录！ |
| 点击此处可从《地学前缘(英文版)》浏览原始摘要信息 |
| 点击此处可从《地学前缘(英文版)》下载免费的PDF全文 |
|
