'Transactions of the Bombay Geographical Society, from September 1850 to June 1852. Edited by the Secretary. Volume X.' [‎200] (333/458)

200
GEOLOGY OF BOMBAY.
wreck of the alluvium mingled with and altered by the intrusion of
volcanic matter. It is difficult to guess the breadth of the outcrop
or actual depth of this group of beds—they seem to extend fifty 0 r
sixty yards into the flats, when they are lost beneath the alluvium—
in which no wells or excavations have been made.
44 . _ 2 . Second Set, or Byculla Chib Beds.—In the bottom of the
Town Drain, from the Grant Road Theatre northward to opposite
the Byculla Club, trap is uniformly found,* and on in the same
general direction various quarries, now used as wells, have
been opened, all in trap. It is found further on in the bottom of the
cuttings on each side of the railway, till it crosses the Mahim road,
re-appearing afterwards in a newly opened quarry close by the railway,
opposite the village of Matoonga.
45. —In absence of evidence of the contrary, and with this much
in favour of the hypothesis, I assume the volcanic mass to be continuous:
it is probably about 100 yards across the surface. Trap is found in all
the wells and other cuttings to the south east in the same general line
through the Native Town, and so probably extends right on to the sea
at Back Bay. In the bottom of the Town Drain, again, about 100
yards to the south-east of the Grant Road, the stratified rock is met
in with in nearly the same form as that presented by the yellow beds
at Love Grove and Malabar Hill. It seems to make a sudden turn to
wards the east, and was met with in the foundation of the Obstetric
Institution, dipping south-easterly, very compact blue trap prevailing
to the depth of thirty feet in the wells and tanks immediately adjoining
It is probably the same bed which is seen about 300 yards further on
at the surface on the western margin of the Baboola Tank, or not im
probably the same that presents itself in the reservoir at Pae Dhonee:
it is either met by a second bed, or split in two by the trap. Al<
Baboola Tank, where it dips S. W. 8 °, it is hardened by the volcanic
mass from below upwards, and at the line of junction contains the
same minerals as are found in the trap itself—the upper portions con
tain impressions of reeds and grasses. It is probably this bed through
which the wells near the residence of Mr. Dickenson, and the former
those prevalent in the Deca
nomical use. ecCl
and bloodstone in considerable quantity, SU ^L^
They are mostly decayed and worthless for
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