116 MIDDLEMISS: THE (JKOLOGY OF IDA!! STATU. 



boundaries. It seems very probable that all are of exactly the 

 game age and belong to one order and time of intrusion. On the 

 other hand it will be observed that 1 have relegated to a separate 

 grouping the quartz-porphyries of the same area, although many 

 authors consider this type to be no more hypabyssal than is grano- 

 phyre. The reason for this is connected with the peculiarities of 

 the appearance of the quartz-porphyry in this area and its easy 

 distinction on the score of its black colour and uniform composition 

 throughout large masses. The subject is further discussed under 

 the description of the rocks themselves. 



Whatever of vagueness may attach to the boundaries of the 

 Aravalli schists and their injection bv veins 



uf^! k ^L^ ]) " mm " of a P Iite ' etc -> thc verv <>PP»site is the case 



with the Idar granite. One of the most striking 

 surface features of the central and western parts of Idar State is 

 furnished by the massive granite and its allied varieties to which 

 I have given the comprehensive name of Idar granite. It builds 

 either fine little groups of rugged and pinnacled hills, often rising 

 500 to (500 feet above the plain, or scattered bosses and tors of 

 smaller size. Some of the latter near the edge of the granite areas 

 are frequently isolated and of grotesque outline, a result probably 

 partly due to the original form taken by the intrusive material 

 as it solidified and partly to unequal weathering by exfoliation 

 in a torrid climate (see PI. 6, fig. 1). Other scattered irregular 

 outcrops appear like clusters of monoliths, some standing and some 

 thrown down. A few of these are of extra large size, such as the 

 cyclopean masses of Sapavada south of Idar town, which are without 

 joint or flaw for lengths of 300 yards. The approaches to and 

 surroundings of Idar town are marked by a picturesque array of 

 many such fine examples, and as is natural, they are frequently 

 surmounted by temples. 



A peculiar manner of weathering into rounded undercut recesses 



is common to certain of the varieties. This 

 ^Remarkable weather- ^^fo | n cayeg) galleries and abrupt CQn _ 



cavities on vertical surfaces which vary in 



size from a few inches across to such as w r ould hold two or more 



persons comfortably sheltered from sun or rain (see PI. 6, fig. 2). 



The outcrops of this rock are of a very scattered nature. One 



of the largest of the groups is seen at Idar, 



Distribution. , , .,, . .« . , 



where hilly masses several miles long and 



