Tectonic restoration of the Precambrian crystalline rocks along the west coast of India: Correlation with eastern Madagascar in East Gondwana

摘要: Abstract New structural–mineralogical data and U–Th-total Pb monazite chemical ages in 27 samples a 430 km long corridor along the west coast of India are combined with existing to reconstruct tectonic set up Meso/Neoarchean crystalline rocks Western Dharwar Craton (WDC). The helps delineate two NW-trending Paleoproterozoic ductile shear zones that limit southern northern margins WDC. zone (metamorphic age: 2.3–2.4 Ga) separates greenschist facies supracrustal belts (2.5 3.3 Ga), foliated granitoids 2.9 Ga) amphibolite anatectic gneisses (>3.0 Ga) WDC from >2.9 Ga granulite ortho/para-gneisses Coorg Block. This is correlated ∼2.4 Ga Betsimisaraka suture east-central Madagascar demarcates accretion between Antongil Block (≈WDC) lithologies Antananarivo domain (≈Coorg Block). system 2.2–1.8 Ga) extending NW into possibly exists as hitherto undiscovered forming basement Mesoproterozoic Sahantaha Formation underlying Neoproterozoic Bemarivo Belt supracrustals NE Madagascar. Within WDC, Meso/Neoproterozoic retrieved poorly-defined uncommon, dispersed within craton, do not define localized craton. metamorphic monazites formed at greenschist/amphibolite conditions preclude metamorphism–deformation associated crustal blocks during Rodinia assembly.