Palaeomagnetism of the-Upper Gondwana-Rajmahal traps, Northeast India

Abstract

For a detailed palaeomagnetic investigation, oriented cores were drilled from the tholeiitic Rajmahal traps basalts (northeast India), which are of a Late Mesozoic age. In total 183 samples were collected from 27 sites spread over the whole trap area. Two sites appeared to be reversely magnetized.

Alternating field and thermal demagnetization resulted in a mean direction D = 314.5°, I = −64.5° (k = 60, a95 = 3.5°; 25 sites), which corresponds to a virtual geomagnetic pole position: 6 3° W, 7° N (dp =4.5°, dm=6°)