Near. the close of the Dravidian Era Kashmir became convulsed by
volcanic disturbance and the Penjal traps were ejected. It was a
time of worldwide disturbance and of redistribution of land and
water. Carboniferous times had begun, and the geographical
changes in
135
the southern limits of the Tethys are regarded as ushering in a
new and last era in Indian geological history the Aryan Bra.
India was now part of Gondwanaland; that vanished continent which
then reached westward to South Africa and eastward to Australia.
A boulder-bed of glacial origin, the Talchir Boulder-bed, occurs
in many surviving parts of this great land. It enters largely
into the Salt Range deposits. There is evidence that extensive
sheets of ice, wearing down the rocks of Rajputana, shoved their
moraines northward into the Salt Range Sea; then, probably, a
southern extension of the Tethys.
Subsequent to this ice age the Indian coalfields of the Gondwana
were laid down, with beds rich in the Glossopteris and
Gangamopteris flora. This remarkable carboniferous flora extends
to Southern Kashmir, so that it is to be inferred that this
region was also part of the main Gondwanaland. But its emergence
was but for a brief period. Upper Carboniferous marine deposits
succeeded; and, in fact, there was no important discontinuity in
the deposits in this area from Panjal times till the early
Tertiaries. During the whole of which vast period Kashmir was
covered with the waters of the Tethys.
The closing Dravidian disturbances of the Kashmir region did not,
apparently, extend to the eastern Himalayan area. But the
Carboniferous Period was, in this
136
eastern area, one of instability, culminating, at the close of
the Period, in a steady rise of the land and a northward retreat
of the Tethys. Nearly the entire Himalaya east of Kashmir became
a land surface and remained exposed to denudative forces for so
long a time that in places the whole of the Carboniferous,
Devonian, and a large part of the Silurian and Ordovician
deposits were removed—some thousands of feet in thickness—before
resubmergence in the Tethys occurred.
Towards the end of the Palaeozoic Age the Aryan Tethys receded
westwards, but still covered the Himalaya and was still connected
with the European Palæozoic sea. The Himalayan area (as well as
Kashmir) remained submerged in its waters throughout the entire
Mesozoic Age.
During Cretaceous times the Tethys became greatly extended,
indicating a considerable subsidence of northwestern India,
Afghanistan, Western Asia, and, probably, much of Tibet. The
shallow-water character of the deposits of the Tibetan Himalaya
indicates, however, a coast line near this region. Volcanic
materials, now poured out, foreshadow the incoming of the great
mountain-building epoch of the Tertiary Era. The enormous mass of
the Deccan traps, possessing a volume which has been estimated at
as much as 6,000 cubic miles, was probably extruded over the
Northern Peninsular region during late Cretaceous times. The sea
now began to retreat, and by the close of