STRATIGRAPHY OF SHAN-TUNG. 35 
of this formation are never so thickly bedded as those of the Ch’ang-hia. 
Individual strata are usually not more than 5 or 6 feet thick, and at 
several horizons the rocks are decidedly slabby; many are dense and break 
with a conchoidal fracture. On weathered surfaces the rock is dark bluish 
gray. Flint is conspicuously absent from all of these Sinian limestones. 
The summit of the formation is marked by a change in the character of 
the sediments, the lower member of the next younger series being yellowish 
in color and notably dolomitic. 




Fic. 9 (Blackwelder).—Ch’au-mi-tién, Shan-tung. Section of Upper Cambrian and Lower Ordovician 
strata in the ridge east of the village. 1 = dense blue-gray limestone; 2 = conglomeratic limestone; 
3 = sandy yellow dolomite; 4 = white earthy limestone; 5 = buff crystalline dolomite; 6 = shaly 
gray limestone; 7 = blue-gray limestone; 8 = slabby yellow limestone; 9 = dense brown limestone, 
The topographic expression of the Ch’au-mi-tién limestone differs 
from that of the other hard Cambrian limestone, the Ch’ang-hia oolite. 
Instead of forming abrupt and often vertical cliffs, it presents steep bluffs, 
in which the relatively thin-bedded strata make steps which can be ascended 
at almost any point. 
Fossils from Ch’au-mi-tién limestone.—At a few restricted horizons, 
fossils, consisting chiefly of brachiopods and fragments of trilobites, are 
fairly abundant. ‘Their affinities are with Upper Cambrian faunas of 
other countries. On account of the interruption, represented by the 
barren Ku-shan shales, it is not surprising that few, if any, of the Ch’ang-hia 
fossils pass up into this series. The important forms in this limestone are 
species of Ptychaspis, Illenurus, and the brachiopod subgenus Plectorthis. 
Almost all of the familiar genera which characterize the Ch’ang-hia lime- 
stone have completely disappeared. 
In the base of the series, dense, slabby limestones, which are, for the 
most part, conglomeratic, predominate through the first 15 meters. From 
loose blocks, near the summit of the mountains at Ku-shan, we have 
specimens of Chuangia batia; it is probable they were derived from 
this basal portion of the Ch’au-mi-tién limestone. 
About 100 to 120 feet, 30 to 36 meters, above the base of the formation, 
and near the top of a characteristic, purplish gray limestone of superior 
hardness, fossils were found in abundance. Strange to say, out of several 
