J. S. Lee—An Outline of Chinese Geology. 411 
and the Fusulina-bearing limestone in the Nan-shan Ranges 
undoubtedly represent at least a part of the Middle Series. 
The Upper Series, though apparently less extensive, is neverthe- 
less known in the Tang-tang district, on the northern border of 
Yun-nan, where it is underlain by the “‘ Permo-Carboniferous 
Limestone’? (=the Middle Series) and overlain by the Trias.1 
The pyroclastic rocks of the Sang-hu-shan,? south-eastern Hu-peh, 
that overlies the Permian coal-bearing series, is in all probability 
a representative of the Upper Series in the middle Yang-tze Valley. 
The post-Middle Carboniferous and pre-Uralian unconformity 
deserves special notice. It is by no means a phenomenon limited 
to eastern Yun-nan. The important rdle that it plays in determining 
the structure of western China may be realized if we examine 
Obrutchov’s report from the Nan-shan and Loczy’s report from the 
mountains of western Su-chuan and western Yun-nan.? 
In central China the unconformity, however, does not appear to 
exist. Willis and Blackwelder, in the course of their reconnaissance 
in western Hu-peh, distinguished a dark bituminous limestone, the 
Wu-shan Limestone,* representing, as may be inferred from the 
fossils so far obtained, the period ranging from the Lower 
Carboniferous to at least the Lower Permian. Further west similar 
limestones > have been found by Richthofen to the south of the 
Ning-kiang, and by Obrutchov in the valley of the Pei-sui-kiang. 
The region of the lower Yang-tze Valley (below Kiu-kiang) affords 
good examples for showing the mixed development of the two 
facies of the Anthracolithic Formation. In this region we have the 
continental deposit of the northern type with coal seams as well as 
the massive Fusulinidea limestone of the south-west. From the 
record of Richthofen’s observations and the Record of the Work 
of the Geological Institute it appears that the Carboniferous- 
Permian rocks in the lower Yang-tze Valley can be generally divided 
into three series in the following order :— 
c. Upper or Coal-bearing Series. Sandstone and coal-bearing shale with 
intercalated marine limestone, yielding a fauna related to that cf 
the Middle Productus Limestone of the Salt Range and of Sumatra. 
The more characteristic species are Reticularia lineata, R. waageni, 
Productus sumatrensis, P. lonyispinus, Richthofenia sinensis, 
Lytionia richthofeni, Orthoceras ef. cyclophorum, Fusulina 
cylindrica, Rhombopora lepidendroides, A viculopecten M’Coyi, etc. 
This series is sometimes represented by a barren sandstone, as 
in the vicinity of the Si-hu, near Hang-chou. 
6. Middle or Fusulinidea Limestone Series. Bituminous limestone 
containing layers of flints and many species of Fusulina and 
Schwagerina characteristic of the Middle Series of the Anthra- 
colithic Formation. 
1 Journ. Coll. Sci. Imp. Univ. Tokyo, vol. xxi, art. 9. 
* China, vol. iii, p. 521. 
3 Loezy, op. cit., vol. i, pp. 692-746; Suess, La Face de la Terre, iii, 
pp. 277, 293. 
* Willis, op. cit., vol. i, pt. i, pp. 274-6. 
> China, vol. ii, pp. 600-1. 
