196 BE'G4 AL
same disturbances that resulted in the elevation of the Himalayas.
The hollow thus formed has been filled in by the fluvial deposits of
the Himalayan rivers; but the gradual raising of the surface has been,
to a great extent, discounted by fresh subsidences, which have been
accompanied by upheavals elsewhere. However this may be, the
uplands of Chota Nagpur date from a very ancient period, while the
Himalayas were thrown up at a time which, from a geological point
of view, is comparatively recent, and the alluvium in the greater part
of Bengal proper has been deposited at a much later date than that
in the Bihar plain west of Rajmahal.
The sub-province of Bihar occupies the north-western quarter of
Bengal. It is divided by the Ganges into two parts-north and south.
North Bihar is a level plain falling very gradually from the foot of the
Himalayas, and with a belt of fairly high land along the bank of the
Ganges. Between these two extremes the general elevation is lower,
and considerable areas are liable to damage by floods. The soil
consists mainly of the older alluvium or bangar, a yellowish clay, with
frequent deposits of kankar ; but in many parts this has been cut away
by the torrents that rush down from the Himalayas, and the lowland,
through which these rivers have at one time or another found an exit
to the Ganges, is composed' of more recent deposits of sand and silt
brought down by them when in flood. In South Bihar the effects of
recent fluvial action are less marked, especially towards the east, where
the outlying hills and undulations of the Chota Nagpur plateau trench
more and more upon the Gangetic plain until, at Monghyr, they extend
as far as the river itself, and offer an effectual opposition to the
oscillations in its course which the more yielding alluvial soil is unable
to prevent elsewhere. The Bihar of our administration contains two
tracts which do not properly belong to it. The SANTAL PARGANAS in
its physical and ethnic features is an integral part of Chota Nagpur,
while MALDA and the eastern part of PURNEA belong to Bengal
proper.
The latter sub-province naturally subdivides itself into four distinct
parts. West Bengal, or the part west of the Bhagirathi, lies outside the
true delta. The eastern portion of this tract is low and of alluvial
formation; but farther west laterite begins to predominate, and the
surface rises and becomes more and more undulating and rocky, until
at last it merges in the uplands of Chota Nagpur. Central Bengal, or
the part lying south of the Padma, between the Bhagirathi on the west
and the Madhumati on the east, was formerly the Ganges delta; but it
has gradually been raised above flood-level, and the great rivers which
formerly flowed through it, depositing their fertilizing silt, yielding an
ample supply of wholesome drinking-water, and draining it, have shrunk
to insignificance. Their mouths have silted up and their banks are
|
![[Digital South Asia Library]](/graphics/thirdlevel.gif)
