﻿300 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 25, 



cide whether it be eruptive or merely metamorphosed, although on 

 the whole the latter is the more probable, has been traced across 

 this part of the country in the direction of the strike for upwards of 

 thirty miles, maintaining its peculiar characters unchanged, although 

 the beds of which it consists are only a few inches in thickness. 



As we approach the northern edge of this region of mica-schist, 

 we perceive that the dip gradually changes from N.N.E. to S.S.W. 

 (see Section No. 1). This change of dip is, so far as the country has 

 been examined, continuous from the Kali to the Ganges, following 

 the general line of strike, although the change is not always gradual, 

 as on my section. The reappearance of some graphite-beds on opposite 

 sides of the synclinal axis on the line of section gives us grounds for 

 supposing that this belt of strata, dipping to the south, is the con- 

 tinuation of those dipping to the north immediately adjoining them. 



Although I have thus far spoken of this tract as consisting of mica- 

 schist, which indeed is the case on the line of my section, we shall 

 find that to the west there is a considerable development of quartzose 

 rocks (to the south of the granite), which gradually pass into a de- 

 cided mica-schist and gneiss as they approximate to the granite. 

 The same is true of the rocks to the north of the line of granite on 

 the east, and we further observe that the schists in the whole of this 

 tract are usually very quartzose. It seems, therefore, highly pro- 

 bable, that the mica-schists of this belt of the mountains have been 

 produced by the action of the granite on quartzose beds that pre- 

 viously to the eruption occupied the whole space. 



On passing the northern edge of this tract of mica- schist we find 

 a decided dislocation of the strata (see Section No. 1), following the 

 line of strike generally, and we come upon a set of rocks of a totally 

 different character, which, however, maintain a great similarity inter 

 se along the line of change. This line is likewise followed by a line 

 of eruptive action, which is possibly connected with the tilting of the 

 northern edge of the mica-schist tract to the south-west. 



This eruptive line (see Map) has been traced, with hardly any break, 

 from the Kali to the Ganges. The rock is for the most part green- 

 stone, but a black basalt also is found in one or two places. The green- 

 stones along this line are frequently seen to pass into decided schists, 

 and the conglomerates and breccias that have been termed "ash" 

 or "volcanic grit" are common. In these conglomerates I have 

 found quartzose pebbles, the exteriors of which are distinctly molten, 

 a nucleus in the centre being left comparatively unchanged ; mixed 

 with these are smaller pebbles, which have been acted on quite 

 through ; and it is curious to observe quartzose beds in the neigh- 

 bourhood distinctly stratified with slates, assuming exactly the appear- 

 ance of these baked pebbles. There seems, therefore, to be sufficient 

 reason to infer that some of these greenstones are contemporaneous 

 with the stratified rocks that accompany them. These are for the 

 most part slates, limestones, and grits or quartzites. The limestones 

 are usually very hard, often associated with steatite in the vicinity 

 of the trap-rocks. Iron and copper likewise follow the line of the 

 eruptive rocks ; the iron usually near the eruption, the copper rather 



