32 RESEARCH IN CHINA. 



and predominant. The Man-t'o contains a sparse Middle or Lower Cambrian fauna in its 

 upper portion; the Kin-lung carries very abundant faunas, which range from Middle Cam- 

 brian at the base to Upper Cambrian and possibly to lowest Ordovician at the top. [Willis, 

 1907, p. 40.] 



The Kiu-lung group is divided into the Ch'ang-hia limestone at the base, 

 the Ku-shan shale, and the Ch'au-mi-tien limestone. 



Ch'ang-hia limestone. The lower portion of the Kiu-lung group is com- 

 posed of green shale and limestone, alternating in character and forming a 

 series 400 to 500 feet thick (120 to 150 meters). 



Ku-shan shale. The middle portion of the group is characterized by 

 dominance of shale, and Doctor Willis gave it the name of the Ku-shan shale 

 in the vicinity of Shan-si, where a single stratum occurs 150 feet (45 meters) 

 thick. 



Ch'au-mi-ticn limestone. The upper part of the Kiu-lung group, the 

 Ch'au-mi-tien limestone, horizontally maintains a uniform character. It is 

 given a thickness of from 400 to 600 feet (120 to 185 meters). It repre- 

 sents a widespread condition of deposition. 



The Upper Sinian, the Tsi-nan limestone, differs in lithologic characters 

 and also contains fossils of Lower Ordovician type. 1 



The lower portion of the Kiu-lung group is designated as the Ch'ang-hia 

 limestone in the Ch'ang-hia district, and in the Sin-t'ai district as the lower 

 limestone. Blackwelder gives the reason for this as follows: 



The classification of the Kiu-lung group into three separate divisions is not appropriate 

 for this district, in spite of the fact that the general paleontologic horizons of the Ch'ang-hia 

 area are recognized here with ease. The black oolite is much reduced in thickness, and is 

 largely replaced by shales. The Ku-shan shale is thicker and carries fossils which belong 

 to the Ch'ang-hia and Ch'au-mi-tie'n formations, respectively, in its upper and lower portions. 

 The Ch'au-mi-tie'n limestone alone retains the general character noted in the first area 

 studied, but its base is somewhat shifted. Thus, the Kiu-lung, which in the Ch'ang-hia 

 district is a group composed of three formations, is in the Sin-t'ai district a consistent 

 formation, containing members of limestone and shale, which are of local occurrence only. 

 [Blackwelder, 1907, pp. 36-37.] 



RELATION OF THE CAMBRIAN TO THE ORDOVICIAN. 



The Ch'au-mi-tien limestone is described by Blackwelder as a very dark 

 gray, finely crystalline rock that has a distinctly blue color where exposed to 

 the weather. 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. 2 



The Tsi-nan formation above the Cambrian is one of the most widely 

 distributed formations in China and is readily recognized by the light-colored 

 argillaceous limestones or dolomites and thin shales of its lower member and 

 the brown dolomitic limestone of its upper member. 3 



'The Cambrian portion of the Sinian is described in detail with sections and distribution of faunas by Dr. 

 Eliot Blackwelder in his description of the stratigraphy of Shan-tung [Blackwelder, 1907, vol.i, part I, 

 pp. 1958] and in the description of the stratigraphy of Chi-Ii in Shan-si [1907, pp. 136-1471,50 that it 

 will not be necessary for me to go further into the details of sedimentation and stratigraphy. 



2 Blackwelder, 1907, pp. 34, 35. 'Idem, p. 44. 



