52 ball: geology of the kajmehai hills. 



grits and pebble bedsj the former presenting an almost vitrified appear- 

 ance near the base. Higher up they present no inconsiderable lithologi- 

 cal resemblance to Barakars. The thickness here exposed is somewhat 

 under 250 feet. They are overlain by a thin bed of trap, over which is a 

 bed of shale upon which there are remnants of another trap-flow. 



In the cliff sections, which are exposed further south, a general 



parallelism seems to exist between the topmost 

 Sections further south. „ ',, ^ . , , 



beds oi the Dubrajpur group and the lowest 



flow of trap ; and unbroken contour lines, marking the junction, may 



often be traced by the eye for several miles. This is not intended 



to imply that there is horizontality, such being not the case. In 



general, the contour lines describe long sweeping curves, at the lowest 



points or hollows in which the trap is often met many feet nearer to the 



base of the hills than it is elsewhere. 



There is not much to guide us to a conclusion as to the time when 



these curves were formed, whether before or since 

 Curves in the strata. 



the outpouring of the trap. But the variation in 



thickness of individual flows, of which evidence will be found on page 



59, suggest the possibility of its having taken place before. At the 



same time this variation in thickness may, in a great measure, be due to 



the character of the trap itself, as, from the nature of its origin, it 



would be a physical impossibility for the respective flows to maintain 



a uniform thickness throughout the whole area over which they 



spread. 



In the neighbourhood of Kharmatand the parallelism just spoken 

 of is much more limited in extent ; in fact, the trap appears to rest upon 

 a denuded and, perhaps, somewhat disturbed surface. That this is the 

 case is seen when one passes along the horizontal shoulders or contour 

 lines of the hills, and encounters trap and sandstones alternately, the 

 former filling up hollows in the latter. 



( 206 ) 



