GENERAL CHARACTERS. 137 



tary rocks, I was for some time in doubt as to whether this does not 

 represent a volcanic agglomerate. Especially the southern slope of 

 the Balchdhura heights where no outcrop of solid rock is seen such an 

 explanation might appear correct, and I met with occurrences remind- 

 in^ me of volcanic bombs. Round balls of amygdaloidal andesite, ap- 

 proximately 2 feet in diameter, on being broken up, were found to con- 

 tain calcite kernels, large in the centre, and decreasing in size towards 

 the periphery. At the same locality I observed blocks of coarse breccias 

 composed of green andesite and red limestone pieces. 



I do not, however, now believe that true agglomerates are anywhere 

 existent in Johar. The same loose debris, such as is met with at the 

 Balchdhura heights, is also found in many other places, where it is 

 obviously produced by the weathering of lavas in which a large 

 number of foreign fragments are involved. These curious lavas are 

 for instance, in situ round the base of the Kiogarh plateau. It thus 

 appears certain that the loose masses alluded to represent debris from 

 lavas, not volcanic agglomerates. The round balls of andesite des- 

 cribed above can well be brought into accord with this explanation. In 

 two places I observed a sphseroidal or sack-like structure in solid lavas, 

 no doubt the result of weathering. To this sphseroidal weathering we 

 may attribute the bomb-like balls. This is the better justified by the 

 solid crust generally seen in true volcanic bombs, being wanting. 

 Finally, as regards the breccias composed of andesite and red limestone, 

 found at the Balchdhura heights, they also accompany the lavas, and 

 are in situ. North of the Kiogarh-Chaldu pass and to the south-east 

 of Kiogarh-Chirchun pass breccias were met with in close connec- 

 tion with the sphaeroidal lavas just mentioned. 



Fragmental rocks. — A few remarks as to the fragmental rocks 

 occurring occasionally among the lavas may be added. The breccia 

 found north of the Kiogarh-Chaldu pass is of a peculiar character. 

 The fragments according to Mr. Holland are chiefly altered pitchstone, 

 probably andesitic in composition, others are serpentine. The narrow 

 interstices between the fragments are filled up by densely red limestone 

 of a laminated structure, the laminae being parallel to the surfaces of 



( W ) 



