330 J- Butler — Rough Notes on the Any ami Ndgds. [No. 4, 



tion of the main axis of elevation, which has thrown the line of main water- 

 shed away to the south-east from its normal south-west — north-east direction, 

 which it assumes at Asalii. The dip of these tertiary rocks of the Barrail 

 is steadily to the south-eastward throughout the whole distance, but it gra- 

 dually changes round to due west, the beds on the highest part, Japvo, 

 turning up at an angle of 35° west. These higher beds are fine slightly 

 micaceous, ochre grey sandstones, very massive and weathering pinkish 

 grey. From this the elevated out-crop of these sandstones tends to south, 

 and is continuous south of the Barak in that direction right away into 

 Manipur, conforming with the change in the strike of all the ridges, 

 the parallelism of which is such a conspicuous feature of the physical 

 geography. To the north-north-west the great change in this moun- 

 tain system is marked by the broad re-entering arm of the Dhansiri, 

 and the sudden appearance of the granitic series in force in the Mikir and 

 Rengma Naga Hills, seen in the bed of the Nambor, and which becomes 

 the principal feature eastward as far as the Garo Hills. Extensive and 

 thick-bedded deposits of clay and conglomerate are seen in the Samaguting 

 dhun, forming broad plateau-capped spurs. I had no time to examine 

 these closely. They appeared to be nearly horizontal, and may belong to 

 the highest beds of the Siwalik formation or the remains of deposits formed 

 prior to the cutting through of the Diphu-pani gorge. Analogous deposits 

 to the last occur in the North- West and Panjab Himalaya. At the base of 

 the Barrail, proceeding to the depression at the sources of the Zullo and Sijjo, 

 the Sub-Himalayan rocks pass downwards into thin-bedded sandy shales, 

 with a steady westerly underlie. Whether the lowest beds represent nuui- 

 mulitic or even cretaceous rocks, it is impossible to say. The thickness is 

 very great, at least 3000 feet ; they rest on an older series of rocks with a 

 totally different lithological aspect. There is uncomformability not always 

 apparent, for they partake of a general westerly dip. The strong bedded 

 younger rocks are but little disturbed, and on the east of the Sijjo come in 

 again at Telligo, nearly horizontal, with a slight dip to east on the main 

 ridge towards Kopamedza, marking an anticlinal axis ; their horizon is 

 however lower. The older beds on the contrary are much crushed, and 

 change their dip and strike very frequently, the result of prior disturbance. 

 They are composed of clay slates and very dark blue, friable shales, alter- 

 nating with others of pale ochrey tint. They are saliferous, and veins of 

 milky quartz are occasionally seen. Several salt springs occur near the 

 bottom of the Zullo valley, under Viswemah, where the Nagas evaporate the 

 water to obtain it. A warm mineral spring also occurs here. Evidence of 

 past glacial action is very marked on the north-east side of the Barrail, 

 where its elevation is close under 10,000 feet. Small moraines project be- 

 yond the gorges of the lateral valley. These moraines originally consisted 



