PART 1.] 
Blavfurd: Geology of Sind. 
19 
of subaerial origin, the clays having, probably, been formed in an alluvial plain, and the 
conglomerates and sandstones deposited by streams and the wash of rain from hills. 
The Manchhar group is uuconformable to the Gaj group. This is proved by the oc¬ 
currence of fragments of the Gaj limestones in places in the Manchhar conglomerates, and 
also by the newer group in places near Sehwan and Kotri overlapping the older and 
resting unconformably upon the upper or lower Nummulitic beds. But, as a rule, through¬ 
out the Khirthar range, the Manchhar beds rest conformably on those of the Gaj group. 
The Sind Sevaliks form a belt of low hills on the flanks of the Khirthar range as much 
as fourteen miles in breadth near Ghaibi Dero, west of Larkana, but usually not more than 
four or five miles wide. South and west of the Manchhar Lake the same rocks occupy a consid¬ 
erable tract of undulating country. They are found on the west side of the Laid hills, 
south-west of the Manchhar - , and they cover much of the ground between the Indus and the 
continuation of the same range to the southward. They are also met with locally about Bula 
Khan’s Thana aud in some of the other valleys of Kohistan. Their extent near the coast 
is obscure, for they appear to change in character in this direction, aud they may be repre¬ 
sented by the Makran group :* but this point has not been determined as yet. 
The Manchhar beds were evidently deposited before the elevation of the Khirthar range, 
since they are tilted up with the beds of which the higher hills are formed. They thus 
mark the close of the tertiary period in Sind, and a break exists between them and the undis¬ 
turbed formations of more recent date. 
7. Recent and Sub-Recent Deposits. 
Although these cover the greater portion of Sind, they possess but little geological 
importance by themselves. They are merely local forms of wide spread formations, and, 
from their simplicity, demand but brief notice. 
The alluvium of the Indus plain is rather sandy, perhaps in consequence of the great 
extent to which sand is carried over the country by wind. Otherwise the alluvium presents 
no peculiarities, or at least none have been observed. 
Along the base of the Khirthar and other ranges are slopes of gravels similar to those 
found in Persia and the dry regions of Central Asia, but on a much smaller scale. These 
deposits are evidently due to the wash of rain aud small streams, and similar slopes occur in 
all countries, but they are peculiarly conspicuous in the desert regions, in consequence of the 
absence of vegetation. 
Large accumulations of gravel and sand are found in many of the valleys between the 
ranges in Lower Sind and amongst the lower hills of the Khirthar. These gravels are often 
cemented into a conglomerate by carbonate of lime. 
Blown sand is frequently found in parts of the Indus plain covering the surface and 
forming low hillocks. To the east of the Indus it covers a large tract of desert country, 
separating Sind from Rajputana. 
On the correlation of the Sind tertiaries ivith those in neighbouring countries. —The 
importance of a knowledge of the rocks of Sind, for the purpose of affording a clue to the 
tertiary geology of other parts of India, has already been noticed. Much additional study of 
the lossils is necessary before anything like accurate correlation is practicable, and it is 
possible that the distribution of organic remains in the tertiary rocks of other parts of India 
may differ slightly from that found in Sind. 
* Records, Geological Survey, India, 187 vol. v, p. 41., 
