456 



Miscellaneous. 



Small-grained greyish-yellow sandstone appears in subordinate beds 

 in this limestone. It is not very hard, contains a considerable quan- 

 tity of clay, and its beds have a thickness which is rather consi- 

 derable. 



The upper beds of this limestone have a great resemblance to 

 that which forms such enormous masses in the Northern Mountains, 

 and it is probable that they both belong to the same formation. 



The limestone of Mount Tzo-Tkhai, which is distinguished by the 

 great pagoda situated on its flank, near the village of Shim-En- Gin, 

 appears equally to belong to the carboniferous limestone. It is very 

 compact, and the particles of quartz give it so great a degree of 

 hardness as to strike fire with steel. Its texture is foliated, but in 

 thick laminae. In some places it has the aspect of a compact mass. 

 It abounds also in caverns, one of which, Thao-Yan-Doun, is remarka- 

 ble for its size. It is situated on a very steep slope, which renders 

 it difficult of access. Many persons ascend the mountain on purpose 

 to visit this cavern, but there are very few who have the courage to 

 descend into it. Many absurd traditions exist among the Chinese 

 respecting it. They pretend that there is a subterranean passage 

 leading as far as Katgane, and that there are stone-bridges over streams 

 running through it, &c. &c. I made the descent into the cave out of 

 curiosity. It appears like a steep gallery, at first tolerably high, but 

 which becomes progressively lower, so as at last to render it necessary 

 to crawl upon hands and knees. It terminates suddenly in a well 

 ascending vertically. It was impossible to explore its farther direction, 

 for at this point the burning wood which served me as a torch 

 gave so little light, that I could scarcely distinguish the nearest 

 objects. The air in the cave is very moist. There are two lateral 

 galleries, one of which is under water ; the other descends very rapidly, 

 and is not any more accessible than the others. The cavern may be 

 about 150 sagenes in length. On the bottoms stalagmites are met with, 

 but no organic remains. 



Coal Formation. — Slate-clay is largely developed to the east of Van- 

 Pin-Koon. So much coal enters into its composition, that in some 

 places it might serve for fuel. The beds often change their direction 

 and sometimes have a dip nearly vertical : the compact diorite (green- 

 stone) which is intruded into this slate in subordinate beds, appears to 

 have been the cause of the irregularity of those which overlie them. 

 The slate-clay alternates with beds of fine-grained sandstone traversed 

 by veins of white quartz, which render it very hard. Beds of coal 

 lie between the slate and the sandstone. 



