Electrical resistivity structure across the Jaisalmer Basin (Rajasthan, NW India) derived from magnetotelluric data: Inferences on basin architecture and basement morphology
2020; Elsevier BV; Volume: 181; Linguagem: Inglês
10.1016/j.jappgeo.2020.104147
ISSN1879-1859
AutoresK. Veeraswamy, K.K. Abdul Azeez, Prasanta K. Patro, Arvind K. Gupta, Narendra Babu,
Tópico(s)Seismic Waves and Analysis
ResumoThe Jaisalmer Basin, one of the prominent among the four subs-basins of Rajasthan basin in the NW part of India, is a highly prospective sedimentary basin as indicated by gas and oil occurrence made in some parts of the basin. This pericratonic basin, which forms the eastern flank of the Indus shelf, carries thick sediments that chiefly deposited during the Paleozoic-Cenozoic period. Deep drilling and conventional exploration studies failed to map the basement under the basin due to its highly thick sediment column. Therefore, deep penetrating magnetotelluric geophysical tool was chosen to investigate the basement depth and morphology beneath the basin. Two-dimensional resistivity structure derived from MT data at 23 sites along a profile across the Jaisalmer Basin successfully imaged the highly resistive Precambrian basement underlying the sediments. MT model shows considerably deep basement at a depth of ~6 km in the central part of the basin, and it becomes very shallow (100–500 m) at the eastern margin of the Jaisalmer Basin. A sharp change in basement depth from ~6 km to ~1.5 km is seen between site 10 and site 11 located west of Jaisalmer. The resistivity structure also characterizes the sedimentary formation that shows low resistivity range of 1–40 Ωm. Additionally, some of the prominent faults in the study area are also identified in the MT model through their low resistivity nature.
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