24 RESEARCH IN CHINA. 
has been destroyed. Masses of Pre-Cambrian quartzite, marble, and 
schists occur elsewhere in Shan-tung, infolded with the gneiss.* It is 
therefore highly probable that Algonkian sediments were spread generally 
over the province, that they were subsequently folded with the basal 
complex, and very largely removed by erosion. In that case the Pre- 
Sinian unconformity includes the time of their deposition, deformation, 
and erosion. It is certainly one of the first magnitude. 
SINIAN SYSTEM. 
The Sinian system of von Richthofen, a succession of sedimentary 
strata of Cambrian and Ordovician ages, is exposed over wide areas in cen- 
tral Shan-tung. The rocks are mostly limestones and shales, which vary 
in sequence considerably from place to place. For general discussion, 
therefore, it is expedient to discriminate only three groups of strata, of 
such a nature that they can be recognized throughout the province in almost 
all localities where the Sinian rocks occur. These are (1) the Man-t’o 
formation, a shaly series partly of Lower Cambrian age; (2) the Kiu-lung 
group, a variable series of limestones and shales of gray and green colors, 
containing Middle and Upper Cambrian fossils; and (3) the Tsi-nan 
formation, a massive limestone, uniform and continuous, which represents 
a part of Ordovician time and perhaps a portion of the Upper Cambrian. 
MAN-T’O FORMATION. 
The Man-t’o formation is primarily a series of red and brown shales 
with interbedded gray and buff limestones, which are usually of an earthy 
composition. ‘These strata were seen in the slopes below the cliffs on all 
sides of the village of Ch’ang-hia, in the hills northeast of Sin-t’ai-hién, 
in those between Kau-kia-p’u and Yen-chuang and again 19 to 24 kilometers 
south of Po-shan. ‘The total thickness ranges from 135 to 225 meters. 
IN THE CH’ANG-HIA DISTRICT. 
Stratigraphy.—The isolated butte called Man-t’o-shan, just south of 
Ch’ang-hia, contains a complete and well-exposed section of the Man-t’o 
formation, from the unconformable contact with the granite below to the 
conformably overlying limestones. As this section is considered typical 
the formation is named from the butte. Similar strata are exposed on 
either side of the valley, in outcrops prevailingly of red and brown color, 
beneath limestone cliffs (Fig. 6). 

* See von Richthofen, China, vol. m1, pp. 201, 213-219; and Lorenz, Beitriige zur Geologie und Paleon- 
tologie yon Ost-Asien, p. 8. 
