Proterozoic crustal evolution of the granitoids from the northern margin of the Chotanagpur Gneissic Complex (CGC), Bihar

Abstract

Since the Proterozoic, considerable expansion of the continental crust has taken place. A significant amount of granitic plutons were deposited on the earth’s crust during this time. The dynamic structure of the earth plays a close role in the genesis of granites and related rocks. Information about the formation and development of the continental crust can be understood from the study of these rocks. The emplacement of large scale anorthosite massif in shield areas was another process that contributed to the Proterozoic expansion of the continental (Mukherjee, et al.,, 2005). One of the primary sources of information regarding the formation and evolution of the continents over geological time is the genesis of granite. Enclaves of supracrustal meta-sediments intrude the Chotanagpur Gneissic Complex (CGC), which is primarily composed of granites, granitoid gneisses, and migmatites exhibiting a wide range of structure, texture, and mineralogy variations.The granitic plutons exposed in the northern fringe of the Chotanagpur Gneissic Complex, CGC, and the associated anorthosites of the Barabar Anorthosite Complex along the northen margin of Bihar holds information about the various magmatic episodes that have taken place in that area millions of years ago.