Chapter XX: Part 8: The Sedimentary Rocks North-West of Pi-Ch’ien-Ch’i, North-Western Shansi

From K’uei-hua-ch’êng to Pi-ch’ien-ch’i we traversed low-lying country at the foot of mountains and hills of the usual archaic formations.

North-west of Pi-ch’ien-ch’i, where we entered the mountains, we encountered extensive beds of sedimentary rocks, doubtless belonging to the Shansi formation. First we came to some very massive conglomerate. This is composed of large cobbles and small boulders, held together by a very hard matrix containing sand and small pebbles. The strata of this conglomerate, which are very marked, and often over ten feet in thickness, dip to the north-west at angles varying from 45° to 80°.

They are interstratified with small, pinched-out seams of coal and soft shale. In places the conglomerate is much contorted.

At Wu-lan-pan, a village six miles north-west from Pi-ch’ien-ch’i, the conglomerate gives place to pink and yellow sandstone, with a much gentler dip (about 20° N.W.).

Beyond Wu-lan-pan the conglomerate again appeared, underlying a dark brown shale, this time at a dip equal to that of the sandstone. After this we came to high mountains, composed chiefly of metamorphic rocks, through which great masses of granite protrude, forming a system of high peaks. No volcanic rock was noticed in this district.

My friend Mr. Nyström, already mentioned in Part I of this chapter, tells me that, when in the mountains north of Sa-la-ch’i (or Saratsi), one day’s journey west of this point, he encountered outcrops of sedimentary rocks exactly similar to those described above, and, like me, he arrived at the conclusion that they belonged to the Shansi formation.