info:eu-repo/semantics/article
CRUSTAL EVOLUTION AND PRECAMBRIAN METALLOGENESIS IN WESTERN INDIA
CRUSTAL EVOLUTION AND PRECAMBRIAN METALLOGENESIS IN WESTERN INDIA
Autor
DEB, M.
Institución
Resumen
Proterozoic supracrustal rocks of continental derivation form the major rock groups in Rajasthan and adjacent states in western lndia and act as repositories for conspicuous base metal mineralization. The continental crust in this region evolved through three main cycles: the Bundelkhand-Berach granite pluton intruded during the Archaean-Prcterozoic transition and formed thc continental nuclei. Extensive migmatization of early volcanics and associated sedimenta during the process of cratonization brought about the evolution of the Banded Gneissic Complex. Stabilization of this basemcnt took place around 2.00a. when two slowly sinking major littoral basins received the huge pile lhe Aravalli sedimentary package through almost a billion years and the subsequent c1astogenic Delhi sedimentation. The recurrent syn-sedimentary mctallogencsis in the Precambrians of western India has been examined by presenting the salient characteristics of six, economically important, metamorphosed, sediment-hosted, stratiform, base metal sulfide deposits: one massive, early Proterozoic, Zn-sulfide deposit in lhe migmatized sediments, probably related to initial basement volcanism: two mid-Proterozoic Pb-Zn-(Cu) deposits emplaced in the Aravalli sequencc through rift-fed exhalations related to basic-felsic volcanism ; threc late Proterozoic Pb-Zn-Cu/Cu/Fe sulfide deposits which formed through sea water - basalt interaction or througb basinal brines enriched by convective circulation. Proterozoic supracrustal rocks of continental derivation form the major rock groups in Rajasthan and adjacent states in western lndia and act as repositories for conspicuous base metal mineralization. The continental crust in this region evolved through three main cycles: the Bundelkhand-Berach granite pluton intruded during the Archaean-Prcterozoic transition and formed thc continental nuclei. Extensive migmatization of early volcanics and associated sedimenta during the process of cratonization brought about the evolution of the Banded Gneissic Complex. Stabilization of this basemcnt took place around 2.00a. when two slowly sinking major littoral basins received the huge pile lhe Aravalli sedimentary package through almost a billion years and the subsequent c1astogenic Delhi sedimentation. The recurrent syn-sedimentary mctallogencsis in the Precambrians of western India has been examined by presenting the salient characteristics of six, economically important, metamorphosed, sediment-hosted, stratiform, base metal sulfide deposits: one massive, early Proterozoic, Zn-sulfide deposit in lhe migmatized sediments, probably related to initial basement volcanism: two mid-Proterozoic Pb-Zn-(Cu) deposits emplaced in the Aravalli sequencc through rift-fed exhalations related to basic-felsic volcanism ; threc late Proterozoic Pb-Zn-Cu/Cu/Fe sulfide deposits which formed through sea water - basalt interaction or througb basinal brines enriched by convective circulation.