File:The Quarterly journal of the Geological Society of London (12734411654).jpg

T. BELT ON THE STEPPES OE SIBERIA.
493
in the immediate neighbourhood

the
fragments distributed over the plains
were entirely unworn. Where ex-
cavations had been made they were
seen to be much more numerous on
the surface than below. The ridges
and hills were covered with shattered
fragments of the rocks of which they
were composed

nowhere were there
any signs that they had ever suppor-
ted glaciers, though probably they
had been exposed to the action of
intense frost. If we suppose that the
plains had been covered with water
forming shallow lakes, the distribu-
tion of the angular fragments over
their surface can be easily accounted
for, as these lakes would be frozen
over in winter, and on the ice break-
ing up in the spring it would carry
away fragments of rocks from the
surrounding ridges and drop them in
various parts of the lakes. I have
reason to believe this cause sufficient,
as I have seen it in operation in the
lakes of North America, and described
it in a paper read before this Society
in 1864.
The country beyond this to the
southward, although still called the
Kirghese steppes, had lost its level
character, and some of the ridges of
crystalline rocks rose to heights of at
least 2000 feet, none of which showed
any signs of glaciation, excepting that
the surface had been shattered by
intense frost. The true plains may
be said to end on this meridian about
lat. 51° N.

whilst to the north-east
they extend diagonally across Siberia
for 3000 miles. Over this enormous
range of country their internal con-
stitution seems to be the same as that
of the plains I traversed

at Sama-
rova, however, on the same meridian
as Ischim,but 345 miles further north,
Erman states that the yellow talcose
clay of which the plains consist rests
on another filled with large fragments
of rock, and says it must be assumed
Ol

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