Mica Inclusions inside Host Mica Grains from the Sutlej Section of the Higher Himalayan Crystallines, India—Morphology and Constrains in Genesis |
| |
作者姓名: | Soumyajit MUKHERJEE |
| |
作者单位: | Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai-400 076, Maharashtra, India |
| |
基金项目: | The study was supported by Department of Science and Technology’s (New Delhi) Grant: SR/FTP/ES-117/2009. |
| |
摘 要: | Abstract: Biotite and muscovite inclusions inside mica host minerals from the Sutlej section of the Higher Himalayan Crystalline were studied under an optical microscope. These inclusions formed possibly by local recrystallization of mica grains during regional prograde metamorphism, with some affected by top-to-SW shear leading to parallelogram shapes. Recrystallization may have been assisted by solution transfer along the cleavage planes of the host grains. The relative competency of deformed phyllosilicate inclusions with the same or different composition to the host depends on the size and orientation of (001) cleavage planes of the inclusions relative to the host. Shearing of mica inclusions led to their parallelogram geometries within the contained mica inclusions. Some of the sheared inclusions deflect cleavage planes in the host minerals and define flanking microstructures. Trapezoid-shaped inclusions are a new finding that deserves more attention for their genesis. These structurally anisotropic inclusions did not originate from sub-grains, secondary infillings or retrogression. These inclusions are also not related to pseudomorphism, isomorphism, folding of the bulk rock etc. Some of the inclusions formed by recrystallization of the host mineral during top-to-SW ductile shear.
|
关 键 词: | Key words: nucleated mica grains inclusions shear zones ductile shear deformation Himalaya |
收稿时间: | 2013/12/12 0:00:00 |
修稿时间: | 2014/5/20 0:00:00 |
Mica Inclusions inside Host Mica Grains from the Sutlej Section of the Higher Himalayan Crystallines,India-Morphology and Constrains in Genesis |
| |
Authors: | Soumyajit MUKHERJEE |
| |
Institution: | Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai-400 076,Maharashtra, India |
| |
Abstract: | Biotite and muscovite inclusions inside mica host minerals from the Sutlej section of the Higher Himalayan Crystalline were studied under an optical microscope. These inclusions formed possibly by local recrystallization of mica grains during regional prograde metamorphism, with some affected by top-to-SW shear leading to parallelogram shapes. Recrystallization may have been assisted by solution transfer along the cleavage planes of the host grains. The relative competency of deformed phyllosilicate inclusions with the same or different composition to the host depends on the size and orientation of(001) cleavage planes of the inclusions relative to the host. Shearing of mica inclusions led to their parallelogram geometries within the contained mica inclusions. Some of the sheared inclusions deflect cleavage planes in the host minerals and define flanking microstructures. Trapezoidshaped inclusions are a new finding that deserves more attention for their genesis. These structurally anisotropic inclusions did not originate from sub-grains, secondary infillings or retrogression. These inclusions are also not related to pseudomorphism, isomorphism, folding of the bulk rock etc. Some of the inclusions formed by recrystallization of the host mineral during top-to-SW ductile shear. |
| |
Keywords: | nucleated mica grains inclusions shear zones ductile shear deformation Himalaya |
本文献已被 CNKI 万方数据 等数据库收录! |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |