首页|Early Paleozoic basement diorite of arc-magmatism from Kutch basin,Western India

Early Paleozoic basement diorite of arc-magmatism from Kutch basin,Western India

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Early Paleozoic basement diorite of arc-magmatism from Kutch basin,Western India
In this study,we report for the first time an Early Palaeozoic basement diorite from the drilled well Nirona-A in the Banni Half-Graben of the Kutch basin,western India.The 40Ar-39Ar dates provided a plateau age of 441.84±2.66 Ma and another pseudo plateau of 441.28±5.82 to 388.08±16.65 Ma for the basement diorite.These ages constrain the basement formation age to the Late Ordovician-Early Silurian period.The obtained basement ages are correlatable with the later part of Cambro-Ordovician alkaline magmatism that has been reported from the Huqf area in Central Oman,whereas their lithological and petrographic correlativity with base-ment diorites occurring in the Dinsi Body of Nagar Parkar igneous complex in Pakistan can also be envisaged.The geochemical studies characterized the diorite with enrich-ment of LILE(Rb,Ba,and K)and LREE(La,Ce,Nd),strong depletion of HFSE(Nb,Sr,P,and Ti),along with weakly negative Eu anomalies.The geochemical signatures indicate their petrogenetic affiliation with mantle-derived magmas,as well as their tectonic setting to be arc-related,having post-collisional continental-arc type affinity.The~440 Ma basement of Kutch,therefore,appears to rep-resent the later thermal event associated with the reworked Neoproterozoic subduction-related suite from Greater India's northwest edge,which has implications for Gond-wana assembly in the northwest Indian subcontinent.

Kutch basin40Ar-39Ar agesEarly palaeozoic basementContinental-arc magmatismCalc-alkaline magmatism

Piyush Gupta、Sandeep Singh、Shakti Singh Rathore、Argha Narayan Sarkar

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Geochronology Laboratory,KDMIPE,Oil and Natural Gas Corporation Ltd.,9,Kaulagarh Road,Dehradun 248195,India

Department of Earth Sciences,Indian Institute of Technology,Roorkee 247667,India

Kutch basin 40Ar-39Ar ages Early palaeozoic basement Continental-arc magmatism Calc-alkaline magmatism

2024

地球化学学报(英文版)
中国科学院地球化学研究所

地球化学学报(英文版)

EI
影响因子:0.33
ISSN:2096-0956
年,卷(期):2024.43(2)