194 KING: KADAPAIH AND 16۸12۲ بای‎ ۰ [PART II. 
clearly bedded as those now referred to, and with the idea that it was 
poured out as a lava, or that it may be a consolidated felspathie dust. 
It is most difficult to conceive how the rock constituting the beds in 
the Táudapurtee valley could have been poured out under water as a lava 
over several square miles, in such a state of liquidity as to give the thin 
strata now exhibited, varying from less than a foot in thickness up to 
three or four feet: and yet there are indications of such an origin in the 
rather thick bed of amygdaloidal felstone already referred to, cropping 
out along the base of the western Oopalpád slopes. "The sub-aqueous 
origin of the felstones 1s very apparent in the extremely regular inter- 
stratification with the sands and shales of this group, and in the general 
and almost total absence of vesicularity. Had the deposition of the 
felsites been sub-aérial they must have been more generally vesicular as 
also more unevenly surfaced. 
Under the view that the rock was originally a dust, one might 
expect to find some traces of fragmentary structure in a bed thus 
derived; but throughout the field there are only the faintest traces of 
such, as for example, in the spotted appearance of specimen No. 3.* 
There is no apparent alteration of strata subjacent to these felsites. 
Indeed it is difficult to recognize this even under 
Have produced no ap- 
parent alteration in con- the great flows of greenstone, for they are gener- 
tact beds. 
ally resting on shales which show no other effect 
than that they are harder perhaps than lower beds and more clearly 
jointed, or cleaved. The thin beds of sandstone are sometimes waved in 
their lamination beneath the great flows of diorite; but these were 
evidently much more powerful in their influence than such thin flows 
of felsite (if these were lavas) could be. 
* It has been suggested to me by Dr. Oldham that the rock may have been originally 
a volcanic mud, and this seems very possible, and even more in accordance with subaqueous 
deposition, as the mud would be more liquified and thus be spread out over a wider area. 
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