138 RESEARCH IN CHINA. 
lithologically similar, occupy the same stratigraphic position, and are 
probably contemporaneous. For the second group, which apparently 
covers both the Kiu-lung and Tsi-nan groups of Shan-tung, the name 
‘‘Ki-chéu group”’ is suggested, because a complete section of the Sinian 
system is exposed on the precipitous front of the Ki-chéu-shan south of 
the Hin-chéu basin. 
The Man-t’o formation in Shan-si differs considerably from the type 
section in Shan-tung. At the base, arkose, conglomeratic, or tufaceous 
sandstones, of variable but slight thickness, are succeeded by an alterna- 
tion of red sandy and calcareous shales with reddish buff, or argillaceous 
limestones. 
In most sections one or two very thin, but persistent, bands of gray- 
green quartzite occur not far above the middle of the formation. The 
red shales are often massive and relatively hard. The total thickness of 
the Man-t’o varies from 180 to 335 feet, 55 to 100 
meters, or about one-half as great as its representa- 
tive in Shan-tung. The upper limit is fairly definite 
at the base of the grayish limestones of the succeeding 
formation. No fossils were 
seen in the formation outside 
of Shan-tung. 
The massive Ki-chou 
limestone comprises gray, 
greenish, and dark brown 


100 FeeY 


rocks, such as are character- Fic. 32 (Blackwelder. Chung-hua, Shan-si, atlas sheet 
istic of the Sinian in Shan- BII).—Man-t’o (Cambrian) red shales lying unconfor- 
; mably upon Pre-Cambrian metamorphic rocks at the 
tung. Certain layers are base of the Ki-chéu-shan, 
oolitic and conglomeratic, but 
in strong contrast to the Algonkian limestones they are never flinty. 
The base of the limestone usually consists of alternate gray and greenish 
limestones, interbedded with calcareous shales of like color. ‘The shales, 
however, make up but a small thickness of the section. Between the red 
shales and the dark upper limestones we have a thickness of about 600 
feet, 180 meters, of these thin-bedded grayish limestones. This part of the 
formation includes the dark oolites and conglomeratic layers, which are in 
most respects similar to those already described from Shan-tung. It has 
yielded a considerable variety of fossils of Middle and Upper Cambrian age. 
The upper portion of the formation, surmounting the above section 
through a thickness of more than 2,000 feet, 600 meters, consists almost 
uniformly of massive dark dolomitic limestone, similar in all its peculiari- 
ties to the Tsi-nan limestone of Shan-tung. Like that formation it rarely 
affords fossils. 
