'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎288] (421/458)

288'
CAPTAIN 6. WINGATE.
tinned heavy Monsoon rain. The heat and humidity of the cli
mate occasion a rapid decomposition of the surface rocks, and when
these happen to be impregnated with iron, they appear to me to be
gradually changed into laterite. The laterite then, according to
this view, is neither a sedimentary nor an igneous rock, but a
metamorphosed rock formed by the action of heat, moisture, and
other existing causes. The greater thickness of the laterite for
mation in the immediate vicinity of the Sea, points also to the con
clusion that the salt spray driven up over the land by the strong
winds prevailing in the Monsoon, is an important agency An office of the East India Company and, later, of the British Raj, headed by an agent. in the meta
morphosing process. It further results from the hypothesis, that
laterite is a recent rock, and is probably even now in process of for
mation.
The facts on which these conclusions rest, are the following. The
cavities of the laterite, unlike those of igneous rocks occasioned by
imprisoned gases, form continuous intermingling channels, through
which water escapes freely, and this circumstance accounts for the
Conkan villages built upon the laterite remaining clean and dry in
the heaviest rain, as well as for their comparative healthiness. The
cavities in question have invariably a downward direction, and seem
to have been formed by the percolation of water through the rock.
The metallic glaze of the interior coating of these cavities is probably
formed of substances held in solution by the percolating water, and a
similar coating may be observed in the cavities of a concretionary
pseudo-laterite, formed of an agglutinated ferruginous gravel, which
is found in the dry beds of nullahs in the Deccan, and other localities,
occasionally overflowed by running water. The true laterite I con
sider to be a rock decomposed and changed in-situ. I have observed
unequivocal examples of various kinds of trap, sandstone, grit, and
metamorphic schist, converted into laterite. The latter in each of
these instances, exhibits peculiarities according to the nature of the
rock from which it has been formed, and under favorable conditions
the conversion has been effected without disturbance of the strata or
beds of the original rock,
Trap-laterite is formed extensively in the Southern Conkan, and a
beautiful example of it may be seen in the Tort of Viziadroog. The en
tire hill on which the fort is built is a mass of laterite, and the scarp
ed sides of the ditches in several parts exhibit the horizontal super - 5