CHARNOCKITES OF INDIA AND ANTARCTICA A COMPARISON BY C. S. PICHAMUTHU, F.A.Sc. (Department of Geology, Bangalore University, Bangalore-l) Received April 27, 1966 ABSTRACT Antarctica is an important component of Gondwanaland, and its geology has many points of resemblance with that of India. The high grade metamorphic rocks, of which charnockite is a conspicuous member, have many characteristics which are common to both regions. Khonda- lites, pink granites and gneisses, and enderbites are associated with charnoc- kites. Regional metamorphism has often charnockitized the country rocks with formation of "phantom charnockites",and ultrametamorphism has resulted in migmatization and rheomorphism. Palingenetic charnoc- kites exhibit intrusive phenomena. Faulting and repeated large-scale block movements are common. Charnockites of widely differing ages have been recognized. A widespread plutonic activity took place about 500 million years ago. INTRODUCTION ANT~CrICA has long been recognized as a component of Gondwanaland but because of the large ice cap which covers most of the land and the extre- mely inclement climate which prevails there, little was known of its geology. This continent forms the central locking piece in many reconstructions of Gondwanaland and, therefore, should have comparative geological relation° ships with South America, southern Africa, southern Australia, and India. Systematic and intensive geological work has in recent years been planned and carried out in Antarctica under the direction and with the co-ordination of the Scientific Committee on Antarctic Research, making use of the geo- logists of the twelve S.C.A.R. countries that are signatories to the Antarctic Treaty. This organized exploration has thrown considerable light on various aspects of the geology of this vast continent. It is not proposed in this paper to compare the geology of India and Antarctica, but an attempt will be made to bring out the more important 2O$
CHARNOCKITES OF INDIA AND ANTARCTICA A COMPARISON
Jun 29, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
