Records of the Geological Survey of India. 
[VOL. X. 
224 
The erratics of the North-West Panjab, properly so called, and to which I would restrict 
the term, are composed of the crystalline rocks and slates of various sorts forming the hills 
which stretch away to the north, or of other rocks, such as limestone, greenstone, &c. 
(but not granite), outcrops of which are known to occur in the adjoining region. 
More or less rounded, and not unfrequently sub-angular, blocks of these rocks of all sizes, 
from 1 to 50 or 80 feet in girth, are met with in the Potwar and the country to the north, 
some details respecting which I have given in the same number of the Records (page 140); 
but, in addition to these undoubted travelled blocks or ‘ erratics ’ properly so called, my colleague, 
Mr. Wynne, at page 124, alludes to “ smaller and less angular erratic blocks of red granite ” 
as being common south of Mt. Tilla and Rotas, and specifics one 7 feet in height and 19 feet 
in girth near the Collector’s bungalow at the Mayo Salt Mines at Ivewra. 
Now, I quite agree with the supposition that “ these red crystalline boulders" are 
derived from the “ cretaceous or olive group of the Eastern Salt Range,” though 
not without a caveat as regards the large block at Ivewra. This block rests on the salt 
marl, and though it may have been derived from the ‘olive group’ by the simple removal, 
bv denudation, of the intervening shales and sandstones, it is, in my opinion, equally 
probable that it has weathered out in situ from the boulder bed which in so many 
places covers the ‘purple sandstones’ immediately overlying the salt marl and is itself 
covered by the ‘ oboluslao ds.’ Conglomerates, with red granite and purplish porpheries, from 
some unknown source, are found along the Salt Range from palmozoic times down to recent, 
and the only thing that favors the cretaceous age of the Kewra block is that, from its size, 
it owes its transport not improbably to ice, and the olive series has yielded proofs of glacial 
agency, which the older beds have not done as yet; but there is no connection between this 
possible ‘ erratic ’ of cretaceous age and the ‘ erratics ’ of the district proper. Both it and the 
similar boulders from the olive group are simply weathered out of beds in the neighbourhood, 
out of the outcrop of clays or conglomerates of pala;ozoic, mesozoic, lcainozoic or recent age, 
and are neither met with in the area wherein the true ‘ erratics ’ abound, nor do the northern 
erratics occur mixed with these within their own (i. e., red granite boulder) area. A sharp 
contrast exists between these red granite boulders and the ‘erratics’ of the Punjab, properly 
so called, both geologically, geographically, and physically. 
The difference between my colleague and myself is one more of definition and terms 
than of fact; but it is one which I am not inclined to lose sight of. 
Regarding my discovery of an ice-scratched boulder of red granite in the cretaceous 
group, Mr. Wynne’s words require a little explanation: “One such boulder polished and 
striated apparently by glacial action was shown me by Mr. Theobald, who found it in a wall 
near Wahali, on the eastern plateau of the Salt Range, not far from where the conglomerate 
just mentioned is in situ.” The fact is that near Wahali the cretaceous boulder clay (much 
resembling the Talchir boulder bed in some respects) constitutes the sub-soil in some fields, and 
the boulders are simply gathered out of the field to clear it, and piled as a low wall along the 
roads, and in such a situation it was (virtually in situ) that my eye was attracted by the glitter 
of the striated surface, wetted by a passing shower. 
An ‘ erratic this block doubtless was, quoad its original derivation and deposition in tlie 
‘ olive ’ series, but it is not an ‘ erratic ’ as regards existing conditions, or to be classed on the 
category of Potwar erratics. 
Equally inapplicable, in my opinion, is the term ‘erratic’ to the red granite blocks 
scattered about Tilla and Rotas. Their original source is, I believe, unknown, though they 
may have possibly come from the Arvali ranges. Their more proximate origin is from the 
denuded boulder clays of the cretaceous group in the Salt Range, or from still older beds such 
as I have already alluded to as covering the palmozoic “ purple sandstone ” of the Salt Range. 
