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

CHINA, MONGOLIA, AND JAPAN. 7
see later, it is probable that the extensive salt deposits of that province are members of the same formation.
Near the city of Ichang, at the eastern mouth of the gorge, the limestone strata,
trending here N. E. and dipping about 8~ to S. E., are covered by apparently
conformable beds of fine-grained, gray sandstone, which, toward the top, soon
merges into a coarse conglomerate. The change is very marked, the upper portion
of the sandstone containing rounded fragments of chert near the contact, and the
lower part of the conglomerate having lenticular deposits of the sandstone. This
transition appears to mark some important change that took place during the forming of these deposits, and the fact that, in transverse section, they border the river
for twelve miles and have a great thickness, would seem to indicate that this change
was not confined to the immediate neighborhood.
This conglomerate is followed by a red sandstone, which above Itu dips easterly,
and below that place westerly. From here eastward the country on both sides of
the river is flat, the rocks being covered for the most part by alluvial deposits;
but in the neighborhood of Yangchi limestone crops out in different places, with a
very irregular strike between N. and W., and a corresponding dip to between N.
and E. From this point to Hankau, the country, if we except a few isolated hills,
is one almost unbroken plain, the ancient bed of the Tungting lake, in which the
older rocks are covered by the lake deposits.
At the town of Shishan (Hien) an isolated hill rises from the plain, its almost
vertical strata trending about N. 65~ E., and consisting of sandstone, arenaceous
shale resembling a similar rock of the Kwei coal field, and a shaly quartzose
conglomerate. The outcroppings of the older rocks that appear, at intervals,
between the outlet of the Tungting lake and Hankau are sandstones and argillites,
which, from their general character and the fact that in one place their trend is
toward a locality a few miles distant where coal is worked, would seem to belong
to the Coal measures. The hills immediately above Hankau are of clay slates and
argillaceous sandstone, and through the cities of Wuchang and Hanyang, stretches
a ridge of sandstone altered to an almost compact quartzite.
The journey from lHankau to the sea was made in a steamer, stopping only at
Kiukiang and Chinkiang, making the knowledge concerning this part of the river
very imperfect. The only sources of information were constant observations, through
a good glass, of the frequent natural sections made by the river, and the scanty
remarks of a few travellers connected with Lord Amherst's embassy.
Below Sankiangkau beds of sandstone and conglomerate, trending S. W. and
dipping 40~-450 to S. E., are exposed, and a few miles further down the river
the city of Hwangchau fu is built on a low ridge of ferruginous sandstone, of which
the raised beds strike due N., dipping about 30~ W. About twenty miles S. E.
from this city, hills of limestone, 800 to 900 feet high, form the southern bank of
the river, the irregular trend of their strata varying from W. to S. W., and the
dip, of about 40~, from S. to S. E. Twenty-five miles below this point the river
breaks through another ridge of limestone, the strata of which have a strike to
S. E. by S. and incline about 40~ to S. W. by W.
The rocks on the outlet to the Poyang lake have all the appearance of limestone,