Miscellaneous. 



455 



The beds of conglomerate occupy, in some localities, nearly a hori- 

 zontal position. In this case the coal included between the conglo- 

 merate and the diorite, occurs in beds of more importance, as, for 

 example, at Daor-Yao to the east of Van-Pin-Koon, where the seam 

 of coal is 1§ archine in thickness. 



That which is worked at Daor-Yao is brittle, and breaks easily 

 into small fragments of the size of a pea. The blacksmiths, and those 

 who work in copper, consider it preferable to any other coal for their 

 use, on account of the intense heat it gives out. 



The conglomerate does not form thick masses. In its upper bed 

 it passes into a true sandstone, which the quartz renders very hard. 

 Occasionally the presence of particles of mica give it a slaty texture, 

 and it becomes friable where clay is principally the basis of its cement. 



The brook Tsin-Schoui-Khe flows 15 li to north of Van-Pin-Koon, 

 and, in cutting through a mass of diorite, it has laid bare all the 

 varieties of this rock. Granitic diorite, compact diorite, and porphy- 

 ritic diorite, alternate with each other, all passing at length into a 

 conglomerate, which appears to differ from that to which the seams 

 of coal are subordinate, and is the dioritic conglomerate properly so 

 called. The beds of this conglomerate, and those of the diorite itself, 

 alternate with beds of ferruginous clay, having a porphyritic appear- 

 ance. This rock in some places passes into euritic porphyry, which 

 being sometimes separated, and afterwards reunited afresh by the 

 same rock, forms a breccia, in which the imbedded fragments of 

 porphyritic rocks are from 1 verchok up to \ of an archine in diameter. 

 This porphyry is of a brick red colour, with white crystals of 

 felspar; its hardness middling, and it forms continuous masses of an 

 irregular appearance. 



Carboniferous Limestone. — This limestone shews itself to the west 

 of Van-Pin-Koon in considerable masses, which may be regarded as an 

 independent formation. The mountains which are composed of it 

 have their flanks so steep, that the summits are sometimes inaccessible. 

 The texture is foliated in thick laminae, and in some localities the 

 stratification of the beds is nearly horizontal. It is traversed by 

 veins of perfectly white calcareous spar, which gives to it a variegated 

 grey colour. A great many caverns of different dimensions, and all of 

 them vaulted, are met with in this limestone, some of which contain 

 stalactites, but they are destitute of organic remains. 



The limestone is traversed in the defile or Yan-Li-Gaou by veins 

 of galena and brown specular iron-ore, of a quarter of an archine or 

 more in thickness. 



