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

80 GEOLOGICAL RESEARCHES IN
in others in low terrace steps. Near Kameta this terrace is covered with a few feet
of clayey sand, underneath which is a bed of whitish clay used for fine tiles; more
generally these terraces are a bluish, sandy clay, rich in recent shells, and fringing
the less precipitous shores of most of the Japanese islands.
First Excursion. May 24th, 1862.-Leaving Hakodade we crossed to the main
island by the low neck of land. This is formed by a bar of stiff clay, perhaps of
the same age as the terrace deposit, which lies a few feet above high-water, and is
covered with drift sand. Along the eastern edge of the neck, the sand has been
raised by the winds into hills, sixty to eighty feet high, the shapes of which change
with every storm, excepting where protected by a sufficient growth of wild rosebushes. Behind these hills the ground is swampy, the water finding a very slow
drainage through the sand.
1 Fig. 9
2
1. Loam. 2. Marsh. 3. Drift sand. 4. Stiff clay.
Following the beach of the northern shore of the bay for several miles, we
turned off at a small village, and, ascending a creek, entered the fertile valley of
Ono, a broad marshy plain on which are some of the principal farms of the island.
An inferior rice and silk are said to be among the chief products.
May 25th.-Branching off from the main road, a few miles beyond the village
of Ono, and following a mountain brook, we reached the lead mines of Ichinowatari.
These mines lie at the entrance to a small valley, on the sides of which the outcropping rocks, containing the veins, are black and gray argillites, slightly calcareous, and highly metamorphosed, in alternating beds; the gray rock being apparently
the younger. These are associated with greenstone, whether eruptive or metamorphic was not ascertained, which occupies most of the valley to its head. On
the summit of the ridge the greenstone was found by Mr. Blake to be succeeded
by a shale, from which he took a calamite, and this again by the black rock already
mentioned.
The veins occur in all of the above rocks; the predominating veinstone being
of magnesite bearing, in nodules, threads, and impregnations, black and yellow
zinc-blende, iron pyrites, galena, and, in places, copper pyrites. The wall rocks are
highly impregnated with small cubes of iron pyrites.
In Japan, as in China, the want of pumping machinery prevents working to any
considerable depth below the adit level. The galleries in this mine were tolerably
well timbered, but low and narrow. From ignorance of the use of powder in
blasting, their means of attacking the rock were-till the application of powder in
mining was introduced by us-confined to the use of pointed instruments, a miner's
pick with one point, similar to our own, a hammer and gad with handle, like the
German Eisen, completing the outfit. The ore is roughly assorted by hand, and
then passed under dry stamps. I was not a little surprised to find, in the mountains of Japan, stamps constructed on the same principle as our own, though the
workmanship and efficiency are far inferior.