I
hare discovered a set of perfectly stratified sandstone rocks, from 80
feet to 100 feet in thickness, and about 200 hundred feet beneath the
surface of the adjoining hills, imbedding large round water-worn boulders 1 cwt. to over a ton in weight. They appear to be a red sandstone formation, but in the absence of a single fossil it is impossible for me to say to what series they may belong.
It has been asserted by some writers on the geology of Ceylon that none of the stratified formations, posterior to
gneiss, had ever been found, and that probably they never would. If
this were the case, we should be obliged to suppose that during the
periods of the accumulation of those formations in other parts of the
globe, this island must either have been dry land or that it was not in
existence, or existing only beneath the waves. From the very fact,
however, of the existence of plumbago alone, such could not have
been the case, and we are thus led to assume that Ceylon, as an island
or part of a continent, must have been more than once submerged and
upheaved, and, if plumbago had at. one time existed as coal, as Sir
Charles Lyell imagines, the last general upheaval must have taken place
subsequent to the carboniferous period.
It
is also a remarkable coincidence that whatever may be the circumstances
under which plumbago is met with in other parts of the island, in Uva
it is found amongst the detritus of decomposed trap rock. It
was also in the neighbourhood of these igneous rocks, where I met with
the marble and clay iron-stone.
With
the exception of gold, all these minerals are, in England, associated
with a coal field, and I am of opinion that if coal be found to exist
in Ceylon, it will, most likely, be met with in the hollows and basins
of the trap hills of Uva.—R.—Local "Times."
THE GEOLOGY OF MADURA AND TINNEVELLY.
From an article in the Madras Mail reviewing
a paper by Mr. Foote of the Geological Department, we take a very
interesting extract referring to the formation of Adam's or Rama's
Bridge between Ceylon and India, and the curious banks of red sand so
conspicuous in parts of the Madras Presidency and also in Travancore :—
The
chief geological interest, of course, lies outside of the gneissic area
on the strip of country, reaching from the coast line for a varying
distance inland, which is occupied by the more recent rocks. This area
is chiefly covered with gritty sandstones belonging to the Cuddalore
beds, lateritic conglomerates and alluvium, but it also contains
several small sub-recent marine beds of limestones and grits, which are
given in the table as "upraised coal reefs," but this, we fancy, must
be a misprint for " coral reefs." Perhaps the most interesting of these
upraised coral reefs is one which forms a striking feature of the north
coast of the island of Rameswaram and apparently extends from Pamban to
Ariangundu as a narrow strip, and then widens out to the north-eastward
to form the northern lobe of the island. This northern lobe seems to
owe its existence entirely to the upraising of the coral, which is here
covered by only a thin coating of alluvium. At present the reef rises
above the water-level for at least ten feet, thus showing a
considerable upheaval of this part of the coast in comparatively recent
times. This is a circumstance which ought not to be lost sight of by
the promoters of the scheme for cutting a ship canal across Rameswaram,
a scheme which Mr. Foote unceremoniously speaks of as " wild." There is
no means of determining exactly when the upheaval took place, but as
Mr. Foote suggests, it senms probable that it was this upheaval which
gave rise to the formation of " Adam's Bridge," which according to
local tradition, once joined the island of Rameswaram to terra firma on
both sides, and was breached about A.D. 1480 by a tremendous storm.
When we consider that plutonic agencies do not seem to be quite
quiescent even yet on
