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

CHINA, MONGOLIA, AND JAPAN. 107
The third line is that of the island of Sagalin (Krafto), which, trending due north
and south, would seem to determine the N. S. course of the western coast line of
Yesso, and the N. S. trend of Nippon from its northern point to the Bay of Yedo.
I have already referred the N. E. line of uplift to the Sinian system of elevation, in a previous chapter; the N. W. trend affecting, as it does, the oldest metamorphic rocks, is perhaps older, and the N. S. trend younger.
Neighborhood of Nagasaki, on the West Coast of the Iland of Kiusiu.
This port is at the head of a long narrow inlet, or fiord, which has nearly a
N. E., S. W. trend, and lies between long ridges, the peaks of which rise to between
1,000 and 2,000 feet above the sea. The skeleton rocks of these hills are metamorphic strata. These were mica schist dipping vertically, in both the ridges where
they were examined, northwest and southeast from the city, and argillaceous and
talco-argillaceous schists, with some limestone, where the eastern ridge was seen
near its southern end, opposite the island of Kabasima. On this island the trend
of the strata is nearly N., S., and they are traversed by a broad belt of granite
bearing fragments of the schists near the planes of contact. On the island Amaksa,
a few miles further east, crystalline, white limestone, and a fine sandstone are
quarried.
The greater part of the country, in the neighborhood of Nagasaki, is covered, to
the summits of the highest hills, with an extensive pluto-neptunian deposit, resembling in general character the volcanic tufa-conglomerate of Yesso.
In places along the eastern side of the bay, and on the islands at its mouth, the
rocks of a coal-bearing formation are exposed. Of these only a coarse, hard sandstone, with threads of coal was seen, as it was not permitted to foreigners to land
at any of these localities. The position of these beds, however, is such as to make
it probable, that the rocks of this coal basin rest immediately, and nonconformably,
on the metamorphic strata before mentioned.
In the terraces which in places fringe this coast, we have again evidence of
oscillations in level, since the beginning of the volcanic epoch. The terraces are
very tufaceous, and seem to be of more recent deposition than the conglomerate
that covers the higher hills.
Bay of Yedo.
Nearly all the country included within the treaty limits, or radius of twenty-five
miles from Yokohama, which area alone is accessible to foreigners, is of recent
formation. A bluff, from 60 to 100 feet high, of bluish clay containing recent
shells, and fragments of pumice, with an upper stratum of more gravelly character,
faces the bay. From the summit of this bluff a plain of the same deposit extends
westward, about twenty miles, rising gently, till the mountains of Oyama. I was
not permitted to ascend these mountains, but from the gravels of the streams
descending from them I judged them to be metamorphic. The fragments seen
were of diorite, gabbro, and serpentine.