l8 LA TOUCHE: GEOLOGY OF WESTERN RAJPUTANA. 



out, leaving, in the centuries that have elapsed since the quarries 

 were first opened, a series of deep narrow chasms, partly filled with 

 debris and sand. The marble varies a good deal in texture, some 

 portions being fine grained and translucent, while the grain of other 

 portions is much coarser. The beauty of the carved work fashioned 

 from this marble is well known. Here also the alteration of the rock 

 into marble is apparently due to the intrusion of a coarse granite, 

 veins of which penetrate the schists in the direction of the strike. 



2. Erinpura Granite. 



To the west of the main range of the Aravallis, in the district of 

 Godwar, the low ground is occupied by a great spread of an exceed- 

 ingly coarse granite, which stretches as far west as the hills north of 

 Erinpura, but is not found further west than this. To the south it 

 extends into Sirohi, and may be easily recognised along the railway 

 to the south of Erinpura by the rounded hummocky knolls into which 

 it has weathered (PI. VIII). The felspar crystals in this granite are fre- 

 quently three or four inches in length, and the other constituents, 

 quartz and mica, are in proportionally large crystals. Where the 

 granite is in contact with the schists, it assumes a gneissose character 

 and is foliated along lines parallel to the junction, but that it is really 

 intrusive is proved by the irregularity of the boundary, by the fact that 

 the granite throws off veins into the schists, that it includes fragments 

 of the latter, and that in some cases, as for instance the marble of 

 Sarangwa referred to above, the rocks in contact with it have been 

 altered. Near the junction with the schists the included masses of the 

 latter have been rolled out into lenticular patches and add to the 

 foliated appearance of the granite; the large felspars are drawn out 

 into lenticular "eyes" surrounded by films of mica and the rock has the 

 appearance of a true gneiss. But at a distance from the boundary, 

 the felspars are arranged in no definite direction, and possess Well 

 ( '8 ) 



