On the occurrence of two intersecting Pre-Cambrian orogenic belts in Singhbhum and adjacent areas, India

Abstract

Intensive structural and stratigraphic studies, supplemented by nine new absolute age data, have led to the recognition of two distinct orogenic belts in the Pre-Cambrian tract of Singhbhum and adjacent areas in India. The Iron Ore orogeny in the south, characterized by the generally low grade metamorphic, N.N.E.-S.S.W. trending formations, had its culmination in the emplacement of the batholithic body of Singhbhum granite (c. 2,000 m.y.). These rocks are separated by a prominent thrust zone (Copper Belt thrust) from the E.-W. striking, generally high-grade meta-morphic rocks of the Singhbhum orogeny whose closing age is 905 to 934 m.y.