STRATIGRAPHY OF SHAN-TUNG. 43 
Ten miles east of T’ai-an-fu, north of the main cart road and just 
east of the W6n-ho, most of the Cambrian section is exposed in a low 
group of hills. As the Man-t’o shales occur in the lowlands, their outcrop 
and their contact with the gneiss are largely obscured by soil. The 
summits are capped by 1oo feet, 30 meters, of Ch’au-mi-tién limestone. 
Beneath this appear green and gray calcareous shales, sometimes platey near 
the top and nodular below, making a total thickness of nearly 200 feet, 
60 meters. The platey beds carry the ‘‘swallow trilobite’”’ fauna already 
mentioned, and thus afford an excellent basis for the correlation of this 
section with others. The shales rest upon 125 feet, 37.5 meters, of gray 
mottled limestones, which are similar to the upper layers of the Ch’ang-hia 
limestone, but the lower portion of that formation seems to be represented 
by the green shales and thin-bedded limestones which form the very base 
of the slope and are obscured by cultivated terraces. This section resembles 
those observed in the Yen-chuang region more than any others, but the 
shales are even more prominent here than in that district. 
In examining these outcrops we found a copious representation of 
the fauna of the upper green shale, as it occurs in the Yen-chuang region; 
here the fossils are found in slabby limestone and green shales, immediately 
beneath the massive strata which resemble the Ch’au-mi-tién limestone. 
From this material five species have been identified, all but the first being 
common, as well, to the fauna from Yen-chuang: 
Straparollina sp. undt. Blackwelderva cilix Walcott 
Agnostus chinensis Dames Drepanura premesnili Bergeron 
Blackwelderia sinensis (Bergeron) 
SouTtH OF PO-SHAN. 
Fifteen miles, 24 kilometers, south of Po-shan, near the village of 
Mei-yii-shan, the hills on the east side of the valley and thence northward 
to the vicinity of Po-shan expose a complete sequence of the Sinian system. 
In the cursory examination which we were able to make, we did not discover 
any important differences between this and the succession at Yen-chuang. 
The Ch’ang-hia limestone is prominent in the cliffs, but a member of green 
shale is included in its upper portion, as in the Kiu-lung-shan. 
TSI-NAN FORMATION. 
One of the most widely distributed formations in China is the one 
to which von Richthofen gave the name ‘“Kohlenkalkstein,’ or Coal- 
limestone. From the fact that it always occurs beneath the coal-bearing 
strata wherever they appear, and bears considerable resemblance to the 
Carboniferous limestone of the Yang-tzi valley, he inferred that it was 
probably of the same age.* Being unsuccessful in his search for fossils 
* China, von Richthofen, vol. 1, pp. 226 and 319. 
