Peninsular Gneissic Complex of the Dharwar Craton - A Suggested Model for its Evolution

摘要: The relationship between the gneisses and greenstone belts of Dharwar 'Craton is reviewed. Arguments for against considering as forming basement, are presented evidences critically evaluated. Stages in evolution craton traced. suggested model envisages recognition an older sequence, largely mafic ultramafic character followed by a major differentiation episode earth's upper mantle giving rise to tonalite magma. bulk Peninsular gneissic complex assigned this event which has not been repeated subsequently. variations shown indicated be result intimate mixing interaction magma with pre-existing lavas associated sediments. banding migmatitic ascribed plastic flow response relatively small directed stresses. suggestion made that split into two stratigraphic units - older, composed rocks distinct chemical character, younger geosynclinal pile lower volcanic phase well-developed sedimentary phase. While show intrusive group, they form basement group sediments deposited long linear basins. explains large number related facts, reconciles different views, takes account prevailing conceptions early crust other parts world.