96 RESEARCH IN CHINA. 
groups; the variegated shales and some of the argillaceous limestones 
resemble certain members of the Man-t’o, but here the likeness ends. On 
the other hand the Man-t’o formation furnishes no counterpart for such 
members of the Fu-chéu series as the white quartzite, yellow sandstone, 
greenish grit, and hard greenish limestones. We are inclined to think 
that in Liau-tung we have to deal with a local lithological development of 
the Cambrian different from that which characterizes western Shan-tung. 
It is probable that the Fu-chdu series constitutes a part of the Cambrian 
system, but any present attempt to make a more definite correlation must 
necessarily be unreliable. 
Volcanic rocks.—The intrusives observed along my route of travel in- 
vade the Yung-ning sandstone and underlying rocks. On the basis of other 
data, however, it is believed that these dikes are of Post-Carboniferous 
age. Von Richthofen mentions porphyries intruded into Carboniferous 
strata at Pon-si-hu,* and states that the basalts in various parts of the 
province of Shéng-king appear to be considerably younger than the 
porphyries.T 
Since the epoch of volcanic activity, the region has been denuded to 
such an extent that all superficial effusive rocks and the original topo- 
graphic features produced by vulcanism have been entirely obliterated. 
It is therefore clear that the eruptions occurred not later than the Ter- 
tiary period, and not improbably in the Mesozoic. 

* China, Volell, pp: 103, 111. 67 Lbid., p. 11%. 
