96 GEOLOGY OF THE COUNTRY 



of a grey colour, small grained, and not stratitied, occur in this formation. 

 This gneiss is composed of dark coloured mica in minute scales, a felspar 

 slightly tinged with red and translucent quartz. In the hornblende rocks, 

 which are distinctly stratified, I observed a vein composed of felspar and 

 quartz — the latter, clear and nearly transparent, the former, a pale reddish 

 white, with perfect foliated fracture, and crystalline structure arranged so 

 as to form a kind of porphyry. 



We now marched to Katdwar, a pretty large town, with a fort, twelve 

 miles north-west of the last. The Dhdhar range was still seen on the 

 left, and the country presented the usual mamillary aspect. The rocks 

 observed were ditferent modifications of granites, hornblende slate and 

 chlorite slate — all these alternating with each other. The line of march 

 in one situation approaches the range of hills, and a similar variety of 

 rocks could be distinctly traced in their base and rocky slopes. The gra- 

 nitic rocks were, 1st, A gneiss of a greyish colour similar to that des- 

 cribed at Gingla. 2d, A red granite, the principal ingredient a dark 

 flesh red felspar — the quartz is in minute quantity and is translucent, 

 and the mica of a dark color is in still smaller proportion. 3d, A reddish 

 coloured gneiss, 4th, A rock, with the distinct structure of gneiss, of a 

 greenish grey colour, in which the mica is replaced by hornblende ; and 

 5th, A rock almost entirely composed of flesh red felspar, with a foliated 

 fracture, and in which are imbedded nearly transparent crystals of quartz. 

 The latter rock, except for the first two miles, within which the horn- 

 blende rocks were principally seen preponderated. It was distinctly 

 stratified — strata highly inclined and dip towards north-east — mica is very 

 rarely seen in it, and indeed is almost wanting. It may be said to form 

 a variety of porphyry, but from its stratiform structure and the arrange- 

 ment of its component parts, I prefer including it with the granitic rocks, 

 in which series it ought certainly to be classed, perhaps, as a distinct 

 * variety, 



