70 A NATURALIST IN WESTERN CHINA 



side by highly inclined strata, among which there is ordinarily 

 noticeable, next to the axis, a double belt of coal-formation, 

 followed on either side by strata of red sandstone standing on 

 edge. Baron Richthofen estimates that " the area of the coal- 

 bearing ground in Szechuan probably exceeds in size the total 

 area of every other province of China." But probably through- 

 out nine-tenths of this area the coal-measures are buried deep 

 beneath the superincumbent strata, and with trifling exceptions 

 can never become available for mining. In the linear elevations, 

 above referred to, the belts of coal-formations, though narrow, 

 are of great length. They are most readily accessible in those 

 places where rivers have cut through and exposed the ends of 

 the seams. Mining is done by means of horizontal adits 

 working from an exposed surface inwards. Coal is very 

 generally obtainable throughout the Red Basin, and is the 

 ordinary fuel of the entire region. 



Iron-ores occur scattered throughout the entire region, but 

 though in the aggregate the iron-smelting industry is a con- 

 siderable one, in no one place is iron made on a large scale. 



Sulphate of iron (copperas) is found in combination with 

 coal in one or two districts, notably in Kiangan Hsien. Lime 

 is common to aU the linear elevations mentioned above, 

 occurring in juxtaposition with coal, and is burnt in kilns in 

 the usual way. 



Gypsum is found and worked in one or two places, notably 

 Mei Chou and Pengshan Hsien, both districts on the Min River, 

 between Kiating and Chengtu. 



Mineral oil in small quantity occurs in the district of Pengch'i 

 Hsien, where a native company has made some attempts to 

 develop the industry, but with unsatisfactory results. 



Other less important minerals occur in small quantities. 

 The precious metals, gold and silver, are not found in the Red 

 Basin proper but in the mountainous country to the west of 

 this region, where copper, lead, and zinc ores also occur. 



In reference to gold it should, however, be mentioned that 

 rude placer mining is carried on during the winter months, 

 throughout the numerous shingle banks exposed in the beds of 

 the Yangtsze, Kialing, and Min Rivers. On the Yangtsze this 

 precarious industry is first to be noted some 50 miles below 



