Magnetic anomalies of offshore Krishna-Godavari Basin, eastern continental margin of India

Journal of Earth system science

M M Malleswara Rao4²  A S Subrahmanyam4²  I V Radhakrishna Murthy2³  K S R Murthy4²  K S Krishna3⁴  K V Swamy1¹ 

[1] Department of Geo-informatics, Adikavi Nannaya University, Rajahmundry 533 105, India.$$;Regional Centre, National Institute of Oceanography, Council of Scientific and Industrial Research, Visakhapantam 530 017, India.$$;Department of Geophysics, Andhra University, Visakhapatnam 530 003, India.$$;National Institute of Oceanography, Council of Scientific and Industrial Research, Dona Paula, Goa 403 004, India.$$

关键词: Magnetic anomalies;    Krishna–Godavari basin;    eastern continental margin of India;    85°E Ridge.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The marine magnetic data acquired from offshore Krishna–Godavari (K–G) basin, eastern continental margin of India (ECMI), brought out a prominent NE–SW trending feature, which could be explained by a buried structural high formed by volcanic activity. The magnetic anomaly feature is also associated with a distinct negative gravity anomaly similar to the one associated with 85°E Ridge. The gravity low could be attributed to a flexure at the Moho boundary, which could in turn be filled with the volcanic material. Inversion of the magnetic and gravity anomalies was also carried out to establish the similarity of anomalies of the two geological features (structural high on the margin and the 85°E Ridge) and their interpretations. In both cases, the magnetic anomalies were caused dominantly by the magnetization contrast between the volcanic material and the surrounding oceanic crust, whereas the low gravity anomalies are by the flexures of the order of 3–4 km at Moho boundary beneath them. The analysis suggests that both structural high present in offshore Krishna–Godavari basin and the 85°E Ridge have been emplaced on relatively older oceanic crust by a common volcanic process, but at discrete times, and that several of the gravity lows in the Bay of Bengal can be attributed to flexures on the Moho, each created due to the load of volcanic material.

【 授权许可】

Unknown