54 RESEARCH IN CHINA. 
the former, though with but slight difference of dip.* The occurrence of 
Jurassic coals in Shan-tung as well as Ssi-ch’uan adds to the value of this 
comparison, although they probably are not present in the Sin-t’ai district. 
Within the area of our explorations, the Sin-t’ai series occurs in only 
three localities. It occupies most of the valley floor around the city from 
which it derives its name, extending 4 or 5 miles, 6 or 8 kilometers, south, 
6 or 7 miles, 10 or 11 kilometers, west, and several miles southeastward. A 
smaller area is exposed 2 or 3 miles, 3 or 4 kilometers, north of Yen-chuang, 
and similar strata underlie most of the lowland, from Po-shan north to 
the fluviatile plain. Exposures of similar rocks were also noted along the 
railroad, from Chéu-ts’un to Ts’ing-tau, 7. e., at Wei-hién and Ch’ang-ling. 



° ! 2MILES 

Fic. 14 (Blackwelder).—Sin-t’ai-hién, Shan-tung. Section of Sin-t’ai (Permo-Mesozoic?) series. The con- 
tact upon the coal-measures below is concealed by fluviatile deposits. a—=soft red shales with many 
layers of coarse conglomerate; b = gray shales and thin sandstones; c = peridotite dike; d = red 
shaly sandstone. 
IN THE SIN-T’AI DISTRICT. 
The lowland southeast of Sin-t’ai-hién furnished the only continuous 
section of the red formation which we were able to examine (Fig.14). The 
one unfortunate feature of the occurrence is the concealment of the basal 
contact with the Po-shan series, by the river Siau-w6n-ho and the alluvium 
of its flood plain. The lowest visible strata are coarse earthy sandstone 
of brick-red color, characterized throughout by cross-bedding in intricate 
festoon-like forms. Certain layers are gritty, but the material is not 
coarse enough to justify the name conglomerate. 
After a slight interval, in which the rocks were not observed, the 
red sandstone is followed by alternating gray silts, shales, and sandstones, 
in regularly parallel strata. Lenticular bodies of purple mudstone occa- 
sionally appear in the gray sandy shales. Where the constituent grains 
are megascopically identifiable, they are seen to comprise quartz, potash 
feldspar, mica, cherts of yellow, red, and black colors, a little gray lime- 
stone, red hematite, etc. There is a notable lack of such minerals as are 
commonly derived from volcanic rocks. The composition of the sandstone 
indicates rather that areas of the T’ai-shan complex were exposed in the 
drainage district whence the material was derived. We know of no other 
rocks in North China which could furnish the potash feldspars and mica 
without sodic feldspars and hornblende. The sandy shales are soft, pure 

* See sections and descriptions quoted in Chapter XIII. 
