124 



PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [DcC. 23, 



are found, as a general rule, forming the summits of the hills, while 

 2 and 5 almost invariably occur at the bottom of the valleys. In the 

 Suichang district, near Kiukiang, of which a section is given (fig. 1), 

 this arrangement is very marked ; from the summit A, about 900 feet 

 in height, and composed of the cherty limestone No. 4, the lines of 

 hills running from W. by S. to E. by N. form a peculiar feature, the 

 landscape appearing like a mass of petrified billows following in suc- 

 cession. At Nanking, as shown in the accompanying section (fig. 3), the 

 series is similar ; but in this district the limestone is largely converted 

 into dolomite, No. 4, however, being precisely similar in both locali- 

 ties ; here, however, no such perfect section is obtainable as at Sui- 

 chang, and it seems doubtful in some spots whether the dolomite 

 should be referred to Nos. 6 or 8. The strike in this district is almost 

 due E. and W. 



Eig. 3. — Section of Coal-beds at Pah-hwei-miau in the NanJcing 

 district. (Scale 4 miles to 1 inch.) 



1500 feet. 



Overlying rocks of 

 Chung-shan seriea. 



■n u 1. • • Alluvial. 



Pah-hwei-miau. 500 feet. ! 



1. arits. 



2. Limestone, No 6. 



3. Coal and Iron-shales, No. 5. 



4. Limestone with chert-nodules, No. 4. 



5. Shales and Grrits, No. 3. 



Proceeding eastwards for about 100 miles, we meet with the Tai-hu, 

 a large lake in the prefecture of Soochow in Kiangsu province, which 

 contains many islands composed of rocks of this formation. In two 

 of these, the Tung and Si (East and West) Tungtings, the lower por- 

 tion of the series is finely developed ; in the eastern portion of one, 

 the Si Tungting-shan, of which a section is appended (fig. 4), the lime- 

 stones come in lying, as before, conformably over the grits and shales 

 of the lower series. As in the other districts, the bed No. 4, contain- 

 ing chert nodules in large numbers, is conspicuous ; further east for 

 some distance a small alluvial plain interrupts the sequence, some 

 low isolated hills seeming, however, to represent No. 5 ; while No. 6 

 appears further to the east in a bold promontory jutting out into the 

 lake, where extensive limestone quarries have been worked for cen- 

 turies. 



These sections, with the foregoing description, will be sufficient to 

 explain the general position and character of the lower sedimentary 

 rocks of Southern China. As will have been seen, they are much dis- 

 turbed, and in some localities altered by the intrusion of igneous 

 rocks, which, especially along the coast chain from Macao to the 

 Chusan islands, form in many localities the characteristic geological 

 formation. Some of these localities have already been mentioned j 



