Petrology across a calcareous rock-anorthosite interface from the Chilka Lake Complex, Orissa: implications for neo-proterozoic crustal evolution of the Northern Eastern Ghats Belt
Mineral assemblages, reaction textures and consideration of deduced mineral reactions in appropriate petrogenetic grids in calc-silicate rocks occurring at the contact of the 0.79 Ga Chilka Lake anorthosite pluton, northeastern part of the Eastern Ghats Belt, India, reveal UHT-metamorphism (T > 1...
| Main Authors: | , , , |
|---|---|
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
Elsevier Science
2008
|
| Subjects: | |
| Online Access: | http://repository.ias.ac.in/67396/ http://www.sciencedirect.com/science/article/pii/S0301926807002495 |
| Summary: | Mineral assemblages, reaction textures and consideration of deduced mineral reactions in appropriate petrogenetic grids in calc-silicate rocks occurring at the contact of the 0.79 Ga Chilka Lake anorthosite pluton, northeastern part of the Eastern Ghats Belt, India, reveal UHT-metamorphism (T > 1000 ° C) at mid-crustal depths (corresponding to 7 ± 1 kbar). This 0.79 Ga thermal metamorphism completely erased imprints of an earlier (0.96 Ga) granulite facies metamorphism in the calc-silicate rocks. The anorthosite and UHT contact metamorphic rocks were overprinted by amphibolite-granulite facies tectonothermal re-working at 0.69-0.66 Ga. Both the anorthosite-induced UHT metamorphism and the high-grade Pan-African re-working are unique for the Eastern Ghats Belt. These new observations provide clues regarding integration and disintegration of Rodinia and Indo-Antarctic correlation in the Precambrian. |
|---|