Geological researches in China, Mongolia, and Japan, during the years 1862-1865.

CHINA, MONGOLIA, AND JAPAN. 77
which are characterized by abundant remains of the mammoth as well as of Bos
urus and Rhinoceros tichorhinus.
We have seen that although the effects of erosion are generally not very extensive
in the steppe deposit, they exist in some places on a large scale. The deeply cut
valley in the Tamchintala is an instance, and one that seemed to me could have been
caused only by fluviatile action. The erosion in the neighborhood of Bilika Noor,
and the presence in the eroded valleys of loam strongly resembling that deposited
by great rivers is another instance. This loam was not often seen, indeed it is
mentioned in my notes only as occurring in the Mingan hills, at Bilika Noor, and
over the steppe deposit near Goshun.
The closing event in the history of the great sea that in comparatively recent
times covered so large a part of Asia, extending from the pole to the Caspian and
Black sea, and from the Ural mountains to near the Great Wall of China, was the
disappearance of its waters from the long trough that reaches from the shores of the
Arctic sea, through the Barabinsky steppe to the Aralo-Caspian depression.
It appears to me that the ancient physical geography of this vast region, and the
effects of its elevation, present one of the most interesting and important fields of
exploration. Whether we consider the meteorological changes that must have been
brought about by the upheaval of so large an area, or the influence of this great
water communication and its currents on the distribution of existing genera, the
geological phenomena that have affected this broad belt of the great continent have,
beyond doubt, had an important influence on the recent history of our planet.
In the following table I have recapitulated the few leading events in the geological history of China and Mongolia which seem to be recognizable.