40 RESEARCH IN CHINA. 



Whether the Nan-t'ou glacier was an exceptional occurrence or a rep- 

 resentative of an extensive system, only in degree affects the deduction 

 that the temperature of early Sinian time was low. Glaciation in latitude 

 31 near sea-level presents, it is true, a problem which refrigeration alone 

 will not solve, especially as no traces of contemporaneous glaciers have been 

 found further north ; but there can be no doubt that it signifies severe cold 

 throughout northern Asia. The fact agrees with the inference which may 

 be drawn from the red sediments of the Man-t'o. That they were not 

 reduced by organic matter proves the barrenness of the shores and seas, 

 although life was abundant elsewhere before and during the Man-t'o epoch 

 and soon after developed richly in the shallows; that it was at first absent 

 and when it appeared in the sea was limited in variety may be attributed 

 to the low temperature. 



Aridity was also probably a condition of the climate. Slight precipi- 

 tation prevents glaciation, even under conditions of severe cold, as is the 

 case in northern Siberia, and the absence of glaciers in the north in early 

 Sinian time may thus be understood. 



Middle Sinian, Kiu-lung group. The Kiu-lung group of Shan-tung is 

 a succession of limestones and shales which immediately follows the Man-t'o 

 formation. Transition beds connect the two. Shale is a common rock in 

 both, but in the Man-t'o it is red, whereas in the Kiu-lung it is green. Lime- 

 stone is thin-bedded and subordinate in the former, in the latter it is usually 

 massive and predominant. The Man-t'o contains a sparse Middle or Lower 

 Cambrian fauna in its upper portion; the Kiu-lung carries very abundant 

 faunas, which range from Middle Cambrian at the base to Upper Cambrian 

 and possibly to lowest Ordovician at the top. 



This Cambrian group was clearly recognized in Shan-tung, but not as 

 distinctly elsewhere. In Shan-si it is represented by the lower part of the 

 Ki-chou limestone, which comprises all the Sinian except the Man-t'o shale ; 

 and on the Yang-tz'i the Kiu-lung horizons are within the great limestone 

 formation, which is the whole Sinian system. 



I proceed to consider the Kiu-lung group as it occurs in Shan-tung. 

 The type locality is the Kiu-lung range, a chain of hills which borders the 

 Won -ho valley on the south, southeast of the district town of Lai-wu-hien, 

 longitude 117 40' E., latitude 36 15' N. The strata dip gently northward 

 and are extensively exposed from the Man-t'o shale below to the Tsi-nan 

 limestone above. The thickness is 900 to 1,000 feet, 275 to 335 meters. 



The component strata are of green shale and limestone. The latter 

 presents several distinct varieties: massive black to gray oolite, nodular 

 or conglomeratic layers of shale, and uniform fine-grained blue limestone. 

 These occur from the bottom up, in the order named, of such thickness and 

 extent as to be considered distinct formations in some districts. 



