Abstract:
In the present study, we have deployed 35 fluxgate
magnetometers and 20 long-period magnetotelluric
sites to derive the electrical conductivity distribution
of Saurashtra region, Gujarat, India. Geomagnetic
field variations (X-north–south, Y-east–west and Zvertically
downward components) recorded at the
above sites are investigated to obtain single-station
vertical field transfer functions. Maps of induction
arrows suggest that the offshore basins are more conducting
than inland basins of the region. Thin sheet
modelling of the induction features suggests that the
anomalous behaviour is strongly influenced by the offshore
and shelf edge sedimentary basins that contain
thick depo centres of Mesozoic sediments. Jamnagar,
Ulva and Mesozoic sedimentary basins on land are also
reflected as high conductivity anomalies that could be
related to the presence of carbonate/shale sediments.
Release of carbon (in the form of thin films) due to
thermal activity of Reunion hotspot on carbonate rich
sediments may give rise to high conductivity anomalies.
