On the Karharbari age of coal-measures of Ray-Bachra area, North Karanpura coalfield

Abstract

In the south-eastern portion of the North Karanpura coalfield, Bihar, two coal seams, known as Ray seams in Ray (23 0 40': 85 0 4') and Bachra seams in Bachra (23 0 41'19": 85 0 5'17") areas, occur in Lower Gondwana coal-measures that comprise a maximum thickness of 140 metres. Coal petrography has established that Bachra seams are the eastward extension of Ray seams. while some workers have described them as Barakars, others have regarded them as Karharbaris. The author examined their geology, field relations of coal seams, borehole logs of Bachra area, and petrography of Ray and Bachra seams in detail, and studied the available palaeobotanical and palynological data. This paper presents conclusive evidences of their being of Karharbari age.