TRANSITIONAL GRANULITE-FACIES MAFIC XENOLITHS IN THE 2.8 GA TRONDHJEMITE-TONALITE-GRANODIORITE (TTG) GNEISSES OF THE EASTERN BEARTOOTH MOUNTAINS, MT/WY: EVIDENCE FOR VARIABLE FLUID INTERACTIONS

2018 ◽  
Author(s):  
Andrew William Osborne ◽  
◽  
Darrell J. Henry
Author(s):  
Fan Guochuan ◽  
Sun Zhongshi

Under influence of ductile shear deformation, granulite facies mineral paragenesis underwent metamorphism and changes in chemical composition. The present paper discusses some changes in chemical composition of garnet in hypers thene_absent felsic gnesiss and of hypersthene in rock in early and late granulite facies undergone increasing ductile shear deformation .In garnet fetsic geniss, band structures were formed because of partial melting and resulted in zoning from massive⟶transitional⟶melanocrate zones in increasing deformed sequence. The electron-probe analyses for garnet in these zones are listed in table 1 . The Table shows that Mno, Cao contents in garnet decrease swiftly from slightly to intensely deformed zones.In slightly and moderately deformed zones, Mgo contents keep unchanged and Feo is slightly lower. In intensely deformed zone, Mgo contents increase, indicating a higher temperature. This is in accord with the general rule that Mgo contents in garnet increase with rising temperature.


2021 ◽  
Vol 35 (4) ◽  
pp. 3011-3031
Author(s):  
Ali Esfandiarian ◽  
Ali Maghsoudian ◽  
Mahsa Shirazi ◽  
Yousef Tamsilian ◽  
Shahin Kord ◽  
...  

ACS Nano ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 1833-1840
Author(s):  
Kuai Yu ◽  
Yang Yang ◽  
Junzhong Wang ◽  
Gregory V. Hartland ◽  
Guo Ping Wang

Author(s):  
Steven K. Spreitzer ◽  
Jesse B. Walters ◽  
Alicia Cruz‐Uribe ◽  
Michael L. Williams ◽  
Martin G. Yates ◽  
...  

Author(s):  
A. Livingstone

SummaryA garnet-olivine metaperidotite and a garnet-amphibole pyroxenite are described. Chemical analyses are presented for six rocks and optical properties and chemical analyses are tabulated for clinopyroxene, almandine-pyrope garnet, and hastingsitie amphibole from the garnet-amphibole pyroxenite. A possible origin for the garnet peridotite and chemically similar granulite facies ultramafic rocks is suggested. The eclogite facies in South Harris is reinstated in the light of the data presented.


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