'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎194] (327/458)

194
GEOLOGY OF BOMBAY.
the debris of the trap on which they rest, no two substances ever
owned a common origin in all their characteristic features so perfectly
dissimilar.
39. —Erratic Masses. Laterite .—This closes the list of our true
alluvia, and before proceeding to describe the older rocks, a short notice
of tho erratics, few in number as they are, may here be given. Though
granites of all descriptions, five or six varieties of limestone, quartz
hornstone, &c. &o., are occasionally to be found on our shores, Laterite*
is the only one deserving the name of erratic, the other rocks and speci
mens, with the exception of the hornstone, appearing all to arrive in the
form of ship's ballast.
The nearest point at which this singular rock occurs in situ is thirty
miles of!: though great abundance of it in all its varieties is to be met
with all around our shores, I have not fallen in with any specimens of it
in the interior of the island. It is found on the little island of Kenery,
separated by seven miles of deep channel from the mainland ; along the
shores of Yersova and Salsette, and so on to Gogo, on the further side of
the G ulf of Cambay, by which it is cut off from all the laterite formations
—it is not found in Kattiawar—how much further north I know not, this
being the limit of my experience. Great blocks of it are seen built into
the fort and walls of Surat—brought I presume from the seashore to the
northward along with the other building material, there being no stone
of any sort in the neighbourhood. In absence of all idea of glacial
action, the only explanation that can be given of the appearance in such
abundance of a rock so heavy, so loose in its texture, so friable and apt
to suffer from disintegration, at such distances from its proper habitat, is
that at no great distance of time it prevailed over a larger area than
that which it now occupies, and that the fragments now found are the
scanty remains of the masses removed by denudation before the
erneigence from the sea of the lands over which they prevail. I admit
that this seems a strained, and is a very ill-supported, hypothesis, yet I
know not what other there is that will so well explain either appear
ance. The abundance in which the laterite is found prevents the
idea of artificial transportation. I have thought I could sometimes
detect it imbedded in the blue clay formation, but do not feel sufficient-
10 ,-Fresh
iltrop ol tl,e fr
uld mark both
,,1 in the latter
itt, being mo:
(si water. Thi
nations of an
and, with
fbvals, disloca
ij to pronounce
(nits, slips, or in
ived: there i
hare not an 1
%
Hand, and u:
posits of sediiiu
hee, a distanc
* See Note D. at the end of the
paper.