BAXA SERIES. -37 



the lime-charged water trickles over large masses of tufa. The outcrop 

 of the dolomite, as laid down on the map, is half a mile wide ; the 

 average dip being about 60°. This indicates a thickness of dolomite 

 (with some interbanded pyritous black slate) of 2,300 feet, if none of the 

 beds are repeated by contortions or faulting. It seems that the dolomite 

 has been shifted to the south by a cross-fault east of Baxa, and after 

 being much denuded, covered up by the Tertiaries, beneath which and the 

 alluvium it probably runs as far as the Tursa. Near the upper end of 

 the Jangti gorge, quartzite dipping at 20° is faulted against the dolomite, 

 whilst it is underlaid by flaggy quartzite at the lower end. Next the 

 latter rock, is some quartzite or quartzitie sandstone, of which the faces of 

 the beds are blackened by carbonaceous matter, and below this the Terti- 

 aries come in. 



The dolomite has been traced as far east as Jainti Hill, but not 

 beyond ; it is probably either cut off by a fault here, or trends north- 

 wards towards Sachaphu Hill, 



Just north of the Tertiaries on the left bank of the Raidak, a section 

 is exposed of a steep anticlinal with east-west axis. The beds in the 

 centre, or the lowest, are purplish-red slates, interstratified with reddish 

 quartzite; over these is 60 or 80 feet of quartzite (of which the surfaces 

 of the beds are frequently blackened by carbonaceous matter), with some 

 layers of graphitic schist, or perhaps graphitic quartz-schist would 

 be a more correct term, as the amount of carbon does not exceed 

 10 per cent, or so. These beds are covered by yellowish shattery 

 quartzite. Between the Eaidak and the Chengti black-looking rocks, 

 no doubt the above graphitic schists are exposed high up on the 

 mountain side, in two or three places, by landslips ; but I observed no 

 trace of them in the Rhekua naddi, where the first rocks north of the 

 Tertiaries are red slates and quartzites. 



The Damudas and the Daling series (as far as the area examined 



Relations to Daling is concerned) being almost exclusively confined 



to the Darjiling territory, and the Baxa beds to 



( 37 ) 



