Geochronological and genetic characterization of basaltic basement from western offshore basins in India

作     者：Piyush Gupta Shakti Singh Rathore Sandeep Singh 

作者机构：Geochronology LaboratoryKDMIPEOil and Natural Gas Corporation Ltd.9Kaulagarh RoadDehradun 248195India Department of Earth SciencesIndian Institute of TechnologyRoorkee 247667India 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2024年第15卷第5期

页      面：372-398页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

基　　金：Oil and Natural Gas Corporation  ओएनजीसी 

主　　题：^(40)Ar-^(39)Ar geochronology Western offshore basins Kutch offshore basin Mumbai offshore basin Kerala-Konkan offshore basin 

摘      要：^(40)Ar-^(39)Ar geochronology,geochemistry,and Sr-Nd isotopic compositions of 30 core samples from 24 offshore drill wells in the Western offshore basins have been used to characterize the genetics of the volcanic basement from the Kutch,Mumbai,and Kerala-Konkan offshore *** from the volcanic basement rocks demonstrate extremely varied isotopic and geochemical fingerprints,which are suggestive of significantly diverse parent magma compositions and emplacement *** tholeiitic basement from Kutch Offshore basin has Ar-Ar ages that range between 60 Ma and 62 *** basement is characterised by a within-plate basalt signature,with depleted isotopic signatures similar to least contaminated Deccan Traps basalts,and a component of subducted crustal *** basement from Mumbai Offshore Basin has eruption ages between 63 Ma and 65 Ma and show a strong within-plate OIB *** and isotopic signatures are consistent with Renuion lavas and an enriched-end member of Deccan Traps ***,Kerala-Konkan Offshore Basin shows significant E-MORB affinity and is characterized by primitive-mantle signatures and least contamination from the upper continental crust,with ages of eruption between 60 Ma and 61 Ma based on obtained^(40)Ar-^(39)Ar *** study suggests that the Mumbai Offshore Basalts’mode of the eruption was comparable with onshore Deccan volcanism,whereas the basaltic basement in Kutch Offshore was formed after the main phase of Deccan eruption and may have been an offshoot of atailof the main Deccan *** parent magma for the volcanic E-MORB basement in the Kerala-Konkan Offshore Basin is thought to have come from mixing along the Carlsberg Mid-Oceanic Ridge and the material from the Réunion plume with the northward movement of the Indian Plate during the Early *** is thought to have occurred concurrently with the formation of the Chagos-Laccadive Ridge.