CHAPTER IV. MIDDLE PALEOZOIC. 





SILURO-DEVONIAN STRATA OF CHINA. 



The preceding chapter upon the Sinian system deals with the stra- 

 tigraphy of the Cambrian and lower Ordovician of eastern Asia. Under 

 the division middle Paleozoic I propose to describe the strata which fall 

 between the Sinian and the Carboniferous, comprising those assigned to 

 the upper Ordovician, Silurian or Gothlandian, and Devonian. 



We may first cite the early observations made by von Richthofen, 

 who, in his second excursion into the geologically unknown China, explored 

 the lower Yang-tz'i, particularly between Kiu-kiang and Nan-king. The 

 only account of his observations that I have yet been able to find is 

 contained in the proceedings of the American Academy of Arts and Sciences, 

 volume viu, May 26, 1869. A number of formations are distinguished by 

 local names. Of these the first four, namely, the Ta-ho, the Lu-shan schists, 

 the Matsu limestone, and the granite intrusions, elude classification. The 

 fifth in von Richthofen's enumeration, namely the Tung-ting sandstone, 

 is also of uncertain position, but was supposed by him to extend con- 

 formably beneath the Devonian limestone, which is next in the series. 

 To this Devonian representative von Richthofen gave the name of Si-ho, 

 and he says of it: 



This is a limestone formation only 600 feet in thickness. The rock is full of chert 

 nodules and contains numerous fossils, chiefly corals, encrinites, and brachiopods. Aulopora 

 repens is of frequent occurrence among them, and other forms, too, indicate a Devonian 

 age. The name is derived from a prominent hill generally known as Single Tree Hill, east 

 of Nan-king, where I first found the fossils. 



Seventh in the series named by von Richthofen are the Nan-king grits, 

 which he described as a gritty and purely quartzose sandstone, mostly red 

 but variegated, alternating frequently with a coarse conglomerate of per- 

 fectly rounded pebbles consisting exclusively of quartz. In certain dark 

 shales which are interstratified occur indeterminable fossil plants. 



Conformably overlying the preceding is the Carboniferous limestone, 

 called Ki-tau, a name which takes precedence of all others for this forma- 

 tion in China. It consists of three members in this locality, namely (i) a 

 lower limestone characterized by Fusulina cylindrica, 1,400 feet, 420 meters; 

 (2) black sandy shales, black lydite, and soft sandstone, about 400 feet, 120 

 meters, thick, containing in the lower strata especially large specimens of 



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