Indian Ocean. These depressions are occupied by salt marshes and
deserts, in which the waters of the streams which flow down the
sides of the basin are now dissipated by evaporation. I am
acquainted with no evidence that the present Iranian basin was
ever occupied by the sea; but the accumulations of gravel over a
great extent of its surface indicate long-continued water
action. It is, therefore, a fair presumption that large lakes
have covered much of its present deserts, and that they have
dried up by the operation of the same changed climatal
conditions as those which have reduced the Caspian and the Dead
Sea to their present dimensions.<11>

Thus it would seem that the Euphrates valley, the centre of the
fabled Noachian deluge, is also the centre of a region covering
some millions of square miles of the present continents of
Europe, Asia, and Africa, in which all the facts, relevant to
the argument, at present known, converge to the conclusion that,
since the miocene epoch, the essential features of its physical
geography have remained unchanged; that it has neither been
depressed below the sea, nor swept by diluvial waters since that
time; and that the Chaldaean version of the legend of a flood in
the Euphrates valley is, of all those which are extant, the only
one which is even consistent with probability, since it depicts
a local inundation, not more severe than one which might be
brought about by a concurrence of favourable conditions at the
present day; and which might probably have been more easily
effected when the Persian Gulf extended farther north.
Hence, the recourse to the "glacial epoch" for some event which
might colourably represent a flood, distinctly asserted by the
only authority for it to have occurred in historical times, is