74 LA TOUCHE : GEOLOGY OF WESTERN RAJPUTANA. 



Station, where the usual " granitic " mode of weathering is well dis- 

 played (PI. Vlil), and extends for many miles to the north along the 

 base of the Aravallis, in Godwar. 



4. Barmer Area. 



Rajputana Survey, i inch = 2 miles, sheet *br '■§*;■ 



39 54 



The quarter sheet of the Atlas of India that would include the 

 Barmer desert has not yet been published, but very nearly the whole 

 of the solid rock that appears above the sand in this area is mapped 

 in the half inch sheet of the Rajputana Survey cited above, and I shall 

 use that in describing the geology of the district. 



On the eastern side of the desert, after leaving the rocky hills 

 south of Jasol, solid rock is first met with on the right bank of the 

 Luni, near the village of Dandali. Here there are two or three 

 conical hills, the highest rising to 1,038 feet above the sea, consisting 

 of a coarse grained hornblendic granite without mica. These hills are 

 quite isolated, but a short distance to the south there are a few low 

 hills composed of Malani rhyolite, a dark grey variety with numerous 

 white crystals of felspar and quartz grains. The granite is traversed 

 by narrow dykes of a fine grained dark grey eurite running north and 

 south parallel to each other. This reck is very similar to the rhyolites 

 in appearance, but it is impossible to say whether the dykes are con- 

 nected with the flows. 



About seven miles to the west of these hills there are three 

 outliers of the Barmer sandstones, of no great height or extent, resting 

 upon an uneven platform of the rhyolites, which are exposed on 

 either side of them. The most northerly of these outliers occurs to 

 the west of the village of Nausar, where there are a few small out- 

 crops of the rhyolites. The sandstones are rather coarse grained 

 with numerous strings of small well-rolled pebbles of white and yellow 

 quartz, and a very few derived from the rhvolites. I could find no 

 ( 74 ) 



