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Deep sub‐crustal features in the Bengal Basin: Seismic signatures for plume activity
Author(s) -
Mall D. M.,
Rao V. K.,
Reddy P. R.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900552
Subject(s) - geology , plume , mantle plume , mantle (geology) , crust , hotspot (geology) , bengal , geophysics , continental crust , seismology , structural basin , oceanic crust , sedimentary rock , basalt , tectonics , paleontology , lithosphere , subduction , bay , oceanography , meteorology , physics
The basaltic Rajmahal Traps (117 Ma), India are believed to be due to a mantle plume. The plausible plume path on the continental side has not been traced probably because of the thick sedimentary cover. These Traps are located close to the Bengal basin; therefore, a re‐examination of the deep seismic velocity structure should help in tracing the plume path on the continental side and its possible relationship to plume activity. Data obtained along four seismic profiles in the Bengal basin were re‐examined, which helped in identifying and modeling strong reflections from lower crust and Moho. The results indicate a 7.5 km/s velocity zone as an underplated mantle material injected by the mantle plume or hotspot at the base of the continental crust. The study also indicates the probable trace of plume in the continental region, a NNW‐SSE trending path east of 87°E with an up‐warp in Moho.