66 Mr Hardie on ihe Geology of' the 



couple of feet ; they are not distorted, but exist in ihe form of 

 huge rectilinear tables of great extent and continuity, the trun- 

 cated edges of which give rise to a structure which Captain 

 Dangerfieid seems to have confounded with the columnar. 



The quartz-rocks, though they preserve the above general 

 characters, vary considerably in respect of their internal texture 

 and composition. The purest variety is of a bluish colour, is 

 translucent at the edges, and has a uniform compact texture. 

 Another has a reddish tint, is nearly opake, contains a consider- 

 able proportion of associated felspar, and has occasionally a fine 

 angulo-granular approaching to granitoidal texture. In some 

 varieties scales of mica are abundant, and in others the mica is 

 replaced by minute grains of a white pulverulent talcose matter. 

 All, however, are remarkable for the extent and continuity of 

 the tabular masses into which they may be split, a property 

 which they possess in common with several other of the schistose 

 rocks in the neighbourhood, and which distinguishes them from 

 a variety of white quartz-rock extensively distributed in Central 

 India, and which is characterized by the numerous joints and 

 fissures which traverse its substance. 



Towards the eastern extremity of the chasm there occurs a 

 band, about eighty feet in breadth, of strata, composed of an 

 extremely soft and friable rock of a light greyish colour and 

 silky aspect, occasionally dull and earthy, with interspersed 

 silky scales. This rock crumbles between the fingers into a fine 

 saponaceous powder ; it is distinctly schistose, though the schis- 

 tose texture is often obscured by the pulverulent nature of the 

 rock, and scales of mica of brass-yellow colour are sparingly in- 

 terspersed through its substance. It may be described as a va- 

 riety of talcose schist. This band is traversed longitudinally by 

 numerous thin seams of quartz, often less than an inch in breadth. 

 These preserve the same rectiUnear course as the strata ; they 

 are of uniform thickness, and the quartz composing them, 

 though, generally speaking, similar to that of the range, is oc- 

 casionally so intermixed with talcose matter, that it assumes a 

 softer and more loosely aggregated character, and exactly re- 

 sembles the rock described above, as occurring immediately to 

 the eastward. From this circumstance, I was led to infer the 

 composition of the latter, and it affords one of the many proofs 

 of the gradual passage of one series into another. In fact, all 



