CHAP. 1.] THE KADAPAH FORMATION. 141 
given, though it is-as yet only negative, that the quartzites of the 
Nullamullays and their southerly extension are generally only grits and 
sands, except in one or two groups. 
This, to a certain extent, indicates that the rocks of the eastern 
side of the field are well up 1n the series, as independently inferred from 
the sections ; though, here again, there is an exception in the Eeshwarna- 
coopum mountain, in the northern part of the range, where sandstone 
beds, not conglomeratic, are very low, or even of the lowest, in 
the series. 
Cleavage has been at times very distinctly superinduced in the 
quartzites, more particularly where the strata are much contorted and 
reduplicated ; and, perhaps, there is hardly anything more indicative than 
these instances that cleavage is the effect of pressure at right angles 
to the resultant planes. The quartzites are very seldom strongly 
cleaved until they are sharply contorted or crushed up in themselves, 
in the same way as is often the case with the slates. 
The following diagrams will show what is meant by the expression 
* beds being crushed up in themselves.’ 
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