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

74 GEOLOGICAL RESEARCHES IN
Dec. 5. Travelled over a rolling country chiefly of granite and mica schist.
Associated with the latter rock is a white dolomitic limestone in apparently interstratified beds, impregnated with specks and flakes of graphite. The general trend
of these rocks appeared to be to the N. W.
The granite had, in places, more the appearance of a metamorphosed conglomerate breccia than of a true granite.
In the afternoon we encamped among outcrops of trachytic porphyry identical in
character with that of Kalgan. I found here all the kinds seen at Kalgan, including a striped variety, and specimens with primary quartz. This porphyry contains
veins and concretions of chalcedony and cornelian.
Dec. 6. Our road lay all day over a rolling country, granitic and syenitic rocks
prevailing, till in the evening we reached the foot of a picturesque granite peak,
the Bogdo oola,1 rising several hundred feet above the surrounding country. To
the west of this we saw a large valley with water or, rather, ice.
An accident detained us here till the next afternoon.
Dec. 7. Started in the afternoon, and after passing the Lamasery of Churinchelu, and travelling a few miles along the foot of the Bogdo oola, encamped for
the night.
Dec. 8. Travelled about 20 miles over a rough country. As the ground was
covered with snow, I saw but little of its character, the outcrops seen being all
granitic.
Dec. 9. This day we were again on the undulating country of the plateau and
the great steppe deposit. Near our camping place were many fragments of volcanic
scoriae and of chalcedony.
Dec. 10. Our road was still on the steppe of yesterday, the surface rising rapidly
toward the north. The rolled detritus on the surface was mostly derived from micaschist, and clay slates, and in a ravine I observed the former rock in place. Near
this we entered the hills that limit the steppe, and found them to be of basalt, at
least as far as the camping place.
Dec. 11. This day found us in the range of hills that, trending S. W. from the
Kentei mountains, forms the watershed between the steppes of the Gobi and the
valleys of the Tula and Orkhon rivers, whose waters flow to the Arctic Ocean.
The country is here made up of rounded, grassy hills, of about the same height,
with valleys remarkable for the regularity of their long, unbroken, cross curves.
The hills are of a black, metamorphosed clay schist, and a compact, greenish rock,
chiefly feldspar and quartz, apparently a metamorphic greenstone. The strike of
the clay rock, where observed, was N. S., and the dip vertical.
The valley bottoms, and the lower slopes of the hills, are covered with a rich,
black earth, the deposit showing no signs of erosion. Our camp this night was in
the Horteryndaban.
Dec. 12. During at least the greater part of the past night we were descending,
and daylight found us in a valley much like that which leads from Kalgan to the
plateau,, a narrow, gravelly descending plain, inclosed between hills several
1 Bogdo, sacred, and oola, mountain.