100 
Records of the Geological Survey of India. 
[vol. v. 
A glance at the map will show that from Haidarabad in Sind to Ahmadabad in Gujrat 
is ail almost unbroken flat. This flat is the south-western extremity of the great plain which 
stretches across Northern India and comprises the valleys of the Indus and Ganges. That 
this plain was at one time an open sea is suggested partly by the line of division which it 
forms between the two entirely distinct geological provinces of the Indian peninsula and the 
Himalayas, partly by the Tertiary marine beds which fringe so large a portion of its edges. 
The high grounds of Kackh and Kattiawar are surrounded on all sides by portions of this 
flat or by the sea. 
There appears much probability that the conversion of this vast area into land has been 
due in great measure to the silt, sand and gravel brought down by the various streams and 
rivers which emerge from the Himalayas and Biluckistan on one side and from the Indian 
peninsula on the other. The process has doubtless been gradual and is still in progress. 
Locally, elevation may have aided, but, on the whole, there is probably at least as much 
reason to assume depression to have been the prevailing movement of the surface. 
The Ran of Kackh appears to have been an inlet of the sea which has been gradually 
filled up by the silt deposited from the streams which enter it. This tract of country is still 
in a debateable condition, being covered with water in the south-west monsoon, when the floods 
brought down by the Bands and Loni, and by the small streams of Kackh, are forced 
back by the waters of the Gulf of Kackh and the old Kori mouth of the Indus, raised above 
their usual level by [the force of the south-west wind, whilst during the remainder of the 
year the whole region is dry land, except in patches. There is a tradition that, at no distant 
period, the Ran was a navigable inland sea; and the appearance of its shores, with the occur¬ 
rence of subrccent marine deposits, confirm this idea, although the period of its conversion 
into dry land remains doubtful, the evidence of the discovery of old boats being confined to 
localities which may have been covered with water after the greater part of the region was 
dry land.* Formerly it is probable that the eastern branch of the river Indus discharged 
itself into the Ran, and the quantity of silt deposited may have been much greater than is 
now the case. 
On the eastern side of Kattiawar the Gulf of Khambayat is also said to be silting 
up. The evidence as to the rapidity of the process is not conclusive, but it may fairly 
be assumed that a gradual extension of the coast is taking place. On tho cast of the gulf, 
the Sabarmati, Main, aud Narbada, the last being one of the great rivers of the Indian 
peninsula, all discharge themselves; and the quantity of silt and detritus brought down by 
them must be very great. 
That the Gulf of Khambayat once communicated with the Ran is probable, as a belt of 
low land, including the brackish marsh known as the Nal, still connects them. Mr. Rogers 
(Quart. Jour. Goo. Soc., 1870, p. 118) has pointed out that while tho black soil of 
southern Giijrat is probably derived from tho neighbouring trap rocks, the light-coloured 
alluvium to the northwards may have been brought down by tlio rivers flowing from countries 
still further to the north; and he has speculated on the possibility of the Indus having once 
discharged its waters in this direction. 
Elevation may also have played its part in the conversion of these alluvial tracts into 
dry ground; and there is better reason for suspecting its action here than farther to the 
northward; for, along tho south coast of Kattiawar marks of a comparatively recent rise 
are numerous. In a MS. report by Mr. Theobald, written in 1858, mention is made of the 
occurrence of barnacles and serpuho on the foundations of an old building beside a creek at 
* Nothing appears to be said of any sea north of Kaehh by the Buddhist-Chinese travellers of the seventh 
century .—See Cunningham’s Ancient Geography of India, Vol. I, p. 302. 
