'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎171] (304/458)

I
S near Tanbnil
‘es, but there sen
luximee, wbrd
ike stratified ni
tersectedfoni;
filing into tlie I
T ro in this for ak
iy tlie silt of l
other, but apfffl
ful little emioe®
duikIs, and is <
ding in organic*
inning the^ !,:
ars umler
teiTupteS- lli;
ntory ofS® 111 '
•SOIOOT OP BOMBAY. ^
ilonte of Bandora, and continues as a great sea wall all along shore,
for ten or fifteen miles at least.
At the old castle on the south eastern extremity of the little island
0 f Versova, it is columnar. Again on the west side of the island, facing
Salsette, it is highly porphyritio, the felspar crystals embedded being
pearly half an inch each way—they are of a dirty yellow colour,—tho
rock itself is brownish black. Just round the promontory, to seaward,
a fine picturesque group of columns rises from high-water mark. They
are of a pinkish brow n with a tint of i ed, as if moss-grown, or weather
worn ; they ring like metal when struck. When broken, it appears that
this is the natural colour of the rock, which, though heavy and hard,
isopen and porous, —a hand specimen much more resembling sand
stone than trap. Further north it turns black again, and narrows to a
pretty unifonn well formed dyke, from fifty to a hundred feet across,
rising here and there into picturesque little hills or islands, and appearing
everywhere for ages to have walled off the sea from a low and easily
abraded coast. At Basseiu it runs into somewhat bolder cliff's, and
presents several beautiful groups of columns, black and compact, like
the rock at Malabar Hill : beyond this, I have not had the means of
examining it. The basalt barrier seems broken through only by the
creek opening into Bombay Harbour. Stretching southward and
eastward from Malabar Point it re-appears at Alibaugh on the Coast,
sixteen miles to the southward, and seems for a long distance to protect
the shore. I have traced it for 70 miles from Bassein to Alibaugh :
beyond this, again, my knowledge is at fault.
10.—From the basalt ridge just described, eastward, for the space of
two miles, the island is almost perfectly flat, rising at the highest soma
eight or ten feet above the level of the sea : much of it would be sub
merged at high tides were the sea not artificially shut out.
TRAP, MOSTLY GREENSTONE, FROM THE PRONGS, THROUGH COLABA,
THE FORT, MAZAGON &c., ON TO SION.
H—A mass of trap, mostly green-stone, extends from the Light
house, at the extreme south-eastern end of Colaba, on all the way to
'■don, on the eastern side of the island, facing the Harbour: instead of
forming one continuous ridge, like the basalt from Malabar Point to