I40 RESEARCH IN CHINA. 
at the southern edge it is overthrust upon the Ta-yang limestone, except 
in the vicinity of Nan-t’ang-mei, where the fault dies out. The succession 
of strata within the mass is interrupted by many internal faults. 
The red shales of the Man-t’o formation occur northwest of Ning- 
shan, in the base of the high flat-topped mountain and in some of the 
neighboring ridges, but the rocks are so badly broken by normal faults 
that the measurement of a section was not attempted. The base of the 
Man-t’o was not seen. ‘The lower members of the Ki-chéu limestone form 
the top of the mountain and most of the range of which it is a part. 
On the south side of the Ning-shan basin the Ki-chéu limestone is 
moderately folded and is overthrust upon the Algonkian. The outcrop 
widens eastward, as the throw of the fault decreases, until near Nan-t’ang- 
mei the oolitic and conglomeratic limestones of the Middle Cambrian appear 
at the base of the Ki-chéu. In this vicinity Willis observed unfamiliar 
strata, which are now believed to represent the Man-t’o formation. They 
consist of dark massive argillite lying upon white quartzite, 50 feet, 40 
meters, thick. The latter rests unconformably upon the flinty gray lime- 
stone of the Ta-yang (Algonkian) series. The base of the quartzite is a 
conglomerate composed of angular fragments of dark and banded flint from 
the Algonkian terrane. This conglomerate is the chief evidence of uncon- 
formity, for the older and younger rocks coincide in dip (Fig. 27, p. 131). 
No fossils were collected in this region. The dark Ordovician limestone 
is as barren here as in Shan-tung, and the Cambrian is rarely exposed. 
At Mi-chéng the upper Sinian limestones are cut by a large dike of 
buff-colored feldspar-porphyry. This is the only dike we observed travers- 
ing Sinian rocks in the mountains between Pau-ting-fu and T’ai-yiian-fu. 
South of Tar-chéu, Shan-st.—Von Richthofen has admirably described 
the picturesque cliffs of Sinian limestone in the valley of the O-shui, north 
of Wu-t’ai-shan* (see Plate XIX). The section in Fig. 34 was measured 
by Willis in 1904 in the same canyon. The Man-t’o formation rests directly 
upon decayed schists of the Wu-t’ai system. The lower portion is red 
sandstone and sandy shale, while shales with thin limestones predominate 
at higher horizons. The red shales are capped by 2,700 feet of Cambro- 
Ordovician limestone, which forms the Ki-chéu formation. Fragments of 
Cambrian fossils were seen in the talus which had fallen from the cliffs. 
Vicinity of Tou-ts’un, Shan-st.—From a point about 6 miles, 10 kilo- 
meters, southwest of Shi-tsui the Sinian rocks extend west-southwest in a 
broadening syncline, far beyond T’ai-yiian-fu. By virtue of their hardness 
and the recent uplift to which they have been subjected, they rise in 
mountains which maintain a nearly continuous northern front 2,000 to 
4,000 feet, 600 to 1,200 meters, high, along the lowlands occupied by the 
towns of Wu-t’ai-hién, Hin-chéu, etc. The highest part of this range 
is known as the Ki-chéu-shan. 
*China, vol. 11, page 365. 
