Abstract:
The Andaman Islands form part of the outer-arc accretionary sedimentary complex belonging to the
Andaman–Sumatra active subduction zone. The islands are characterized by thick cover of Neogene
sediments along with exposed ophiolite rocks at few places. A regional magnetic survey was carried
out for the first time over the Andaman Islands with a view to understand the correlation of anomaly
signatures with surface geology of the islands. The residual total field magnetic anomaly maps have
revealed distinct magnetic anomalies having intermediate to high amplitude magnetic signatures and
correlate with the areas over/close to the exposed ophiolite rocks along the east coast of north, middle
and the south Andaman Islands. The 2D modelling of magnetic anomalies along selected E–W profiles
across the islands indicate that the ophiolite bodies extend to a depth of about 5–8 km and spatially
correlate with the mapped fault/thrust zones.
