- Dona Paula, Goa, India.
- +91-0832- 2450327
- iiosc2020[at]nio[dot]org
Abstract Submission No. | ABS-2022-13-0183 |
Title of Abstract | Structure and tectonics of the Indian Ocean: current status of knowledge and some unresolved problems |
Authors | V. Yatheesh* |
Organisation | CSIR-National Institute of Oceanography, Dona Paula, Goa 403004 |
Address | Geological Oceanography Division, CSIR-National Institute of Oceanography Dona Paula, Panaji, Goa, India Pincode: 403004 Mobile: 9422415995 E-mail: yatheesh@nio.org |
Country | India |
Presentation | Oral |
Abstract | The Indian Ocean was formed as a result of fragmentation and dispersal of the eastern sector of the Gondwanaland since the Late Jurassic. In this framework, various sectors of the deep ocean basins and the bordering continental margins of the Indian Ocean were formed by the different episodes of rifting and subsequent drifting among the continental blocks of Africa, Antarctica, Australia, India, Madagascar and Seychelles, along with the several identified microcontinental blocks. The deep ocean basins in the Indian Ocean contain the imprints of this plate tectonic history, which was further influenced and modulated by several major events such as Kerguelen, Marion and Rèunion hotspots volcanism, the India-Eurasia collision and the deformation of the Central Indian and Wharton basins. Therefore, a detailed understanding of the structure, age and evolution of all these ocean basins are important to trace the plate kinematic history of the Indian Ocean and the bordering continental margins. The geophysical investigations carried out in the Indian Ocean and the adjacent continental margins for the last four decades created significant knowledge base on the structure and tectonics of different sectors of the Indian Ocean. These constraints were further used to provide improved plate tectonic evolution model to decipher the stage-by-stage evolution of the Indian Ocean. A detailed review of the existing knowledge on the structure and tectonics of the Indian Ocean reveal the existence of several problems pending satisfactory explanations, largely due to inherent tectonic complexities or the unavailability of the adequate data. Some of the major problems that need to be addressed/examined are the existence and extent of the Prathap and Kori-Comorin ridges, locations of the continent-ocean boundaries around the continental margins of India, timing of formation of the deep offshore regions adjacent to the Indian continental margins, deeper crustal structure and trend of the 85°E Ridge, the crustal configuration as well as the extent of the postulated microcontinental slivers, and cause of intense seismicity over the Chagos Bank. The way to go forward to address these problems is the acquisition of high-resolution and deep penetrated multichannel seismic reflection data, seismic refraction data using Ocean Bottom Seismometers (OBS) and closely-spaced sea-surface and deep-tow magnetic profiles along with high-resolution seafloor mapping. This could probably be achieved by international collaborative efforts through the Second International Indian Ocean Expedition. |