Open Access
Subscription Access
Open Access
Subscription Access
Paleoproterozoic Boninite-Like Rocks in an Intracratonic Setting from Northern Bastar Craton, Central India
Subscribe/Renew Journal
Boninite-Like rocks represented by high-Ca boninitic dykes, melanogabbro dykes, recrystalized plagioclase bearing high MgO dykes and high-Mg nonte suites occur at few places in the vicinity of Meso to Neoproterozoic Chhattisgarh sedimentary basin in the northern Bastar craton in Central India. These rocks are formed in an intracratonic setting, not at convergent margin, similar to Archaean bonmitic rocks reported from intracratonic settings such as Mallina Basin, Northwest Australia and Abitibi, Optica regions of Canada. These high-MgO mafic dykes show a strong boninitic affinity with high SiO2 (>52%), high MgO (9-15%), low TiO2 (0 30-0 54 wt%) and strong LILE enrichment. These unusual dykes show distinct mineralogical, petrological and geochemical charactenstics and are totally different to that of the normally occurring abundant metadoleritic and metagabbroic dykes in Chhattisgarh region. The generation of bonmite magmatism requires unique thermal conditions such as shallow melting, elevated geothermal gradient and subducted slab flux. On the basis of field, geological, petrological and geochemical inferences on these Chhattisgarh boninitic and nontic dykes, a two-stage melting model and derivation from a strongly depleted mantle source, enriched later by metasomatic events is suggested.
Keywords
Boninitic-Noritic Dykes, Chhattisgarh, Geochemistry, Bastar Craton.
Subscription
Login to verify subscription
User
Font Size
Information
Abstract Views: 186
PDF Views: 2