118 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
2. A few Remarks on the Grotocy of the Country surrounding the 
GuuF or CampBay, in WESTERN InpIA. By Arex. Rocrrs, Bombay 
Civil Service. 
(Read June 23, 1869 *.) 
Tue rapid silting up of the Gulf of Cambay gives particular interest 
to an inquiry into the geological conditions which probably shaped 
it in remote ages, and the gradual changes which have modified its 
original form, and brought it to its present state. The geological 
features of the country surrounding the Gulf afford, when taken as 
a whole, an unusually clear clue to the nature of some of these 
changes, and may assist us in tracing what may have taken place in 
the region between the head of the Gulf and the present mouths of 
the Indus, and in the desert between Rajpootana and Sind. The 
former comprises within itself the Great Runn of Cutch, which has 
already received much attention from the most distinguished geolo- 
gists. It will be seen, from the accompanying rough geological map of 
the Gulf and its neighbourhood (fig. 1), that primary or metamorphic 
rocks are traceable in its immediate vicinity only in a small tract on 
its west coast. Here they appear in isolated peaks of from a few to 
two or three hundred feet in height above the alluvium that sur- 
rounds them near Chumardee, but are also found on and below the 
general level of the country for about fifty miles to the north and 
north-west of that village. They also appear on the east of the 
river Myhee to the north and north-west of the hill of Powaghur 
in a precisely similar position with reference to the surrounding 
country to those on the west of the Gulf. In both these localities 
even the highest points of the granite peaks show signs of weather- 
ing, and probably also of the erosive action of waves. The same 
effects being visible down to the present level of the country, and 
detritus derived from the long-continued denudation of the higher 
rocks having in some cases accumulated round their base to a con- 
siderable depth, prove that the raising of the level of the land, the 
cause of the granitic rocks now appearing as islands in a sea of 
alluvium, must have occupied immense periods of time. Granitic 
and metamorphic rocks appear in regular ranges, and extending 
over large tracts of country, for the first time fifty or sixty miles 
north-east of Ahmedabad, or fully a hundred miles from the head 
of the Gulf, running in an easterly and north-easterly direction. 
Between these and the desert that lies between Rajpootana and Sind 
to the north-west, and as far as Cutch and Kattywar on the west 
and south-west, there is not a rock to be found; all is deep allu- 
vium, of consistencies varying from that of almost pure siliceous 
sand to that of the rich light-coloured “ Goraroo” soil of Goozerat 
(which may in some places be cut almost as butter may with a knife), 
and the deep black “ Regur” or cotton soil. Through this alluvium 
the Saburmuttee and other rivers cut their way, frequently exposing 
sections of 20 feet or 30 feet in depth without a trace of stone in 
* For the Discussion on this paper see p. 441 of the last volume of the 
Journal. 
