40 mallet: geology of darjiling and western duars. 



each case they are covered by Daling slates dipping at the same angle, 

 but the absolute junction is not visible. In the Pugo, again, the older 

 series consists chiefly of crushed sandstones, with some shale and thin 

 seams of coal. The highest beds are graphitic schists, with thin 

 layers of grey quartzite, dipping north 30° east, at 60°. Immediately 

 covering these, with similar dip, are alternating dark greenish-grey 

 and light green, slightly greasy slates, which may be traced for at 

 least some hundred yards up stream. The junction is perfectly sharp, and 

 the slates do not contain any carbonaceous matter. 



In the Mahanaddi, indurated Damudas of the usual character, with 

 coal seams, &c, are visible for about three quarters of a mile. The last 

 beds, in ascending the stream, are of crushed massive dark-grey sand- 

 stone, within 6 feet of which are light green slates dipping at 80° to 

 north-north-west. These continue for over a mile and a half up stream, 

 with a remarkably constant lithological character, until they begin to 

 graduate into mica schist and gneiss. Throughout the entire distance 

 I did not observe a trace of carbonaceous matter. 



In some other sections the junction is not so perfectly sharply 

 marked as in the above. In the Tista, for instance, Damuda sand- 

 stone and light green slate are interbanded for some yards, and in 

 the neighbourhood of Pankabari the junction is sometimes difficult to 

 determine. Between Rani Hat and the cart road, there is a band of slaty 

 conglomerate at the base of the Dalings, of insignificant thickness, which 

 dies out to east and west. 



The light green slightly greasy slates, sometimes interbanded with 



a dark greenish-grey kind, mentioned in some of the 

 Lithology. 



above sections, are the most prominent variety of 



rock for some distance north of the Damuda outcrop. In many places 

 they are thinly fissile, but there is a system of divisional planes (some- 

 times more than one), generally at an angle of 30° or 40° to the planes 

 of fissility, which causes the slate to break across into small pieces. Not 

 unfrequently the rock contains thin laminae of white quartz parallel to 

 ( -40 ) 



