.3^ 



14 GEOLOGICAL RESEARCHES IN 



and porphyry, shows that these older rocks had been subjected to an extensive 

 denudation. 



In the narrow gorge, through which the creek finds its way from the Chaitang 

 valley to the Hun river, the contact between the limestone and porphyry con- 

 glomerate is visible "(Fig. 1). The limestone strata 

 are cut through at a right angle, and are seen to 

 01 dip about 80° to the S. 

 j'^ljiijillll I did not obtain an observation of the dip of the 



'' ^yfllTTfffll I'l'^fllll I n conglomerate in this section to know whether it 



ii" o a°/'//l'i/i'i'''i\l!illllili conforms to that of the limestone. 



^0° °'^''<^/! i//'ijll'ii)l!lilrl'lljlll' The coal district of Chaitang forms an area of 



low hills, and is limited on the north by the por- 



a. Upper limestone. 



6. Lower porphyry conglomerate. phyry Conglomerates, whose high and rugged hills 



are overtopped in the background by the yellow 

 cliffs of the limestone. To the south rises a high ridge consisting, apparently, of 

 the rocks of the Coal measures and dykes of porphyry, and separating the coal 

 district of Chaitang from that of the Wangping creek. To the west is a high and 

 hilly country mainly of porphyry. 



About four miles W. N. W. of Chaitang, in the midst of this porphyry, lies the 

 small coal district of Chingshui, and about five miles S. W. are the anthracite 

 mines of the Tatsau district. 



The vaUey of Chaitang has been occupied by a lake, the alluvial deposits of which 

 now form terraces and cap hills over one hundred feet high. The trend of the tilted 

 strata in the centre of the district is very uniformly N. W., and the dip is to N. E. 

 and to S. W., forming both synclinal and anticlinal ridges. But as we approach 

 the western end the trend becomes irregular, though the dip is toward the porphyry. 

 Indeed, the edge of these mountains of porphyry, seems to mark the line of a great 

 fault, perhaps combined with an immense overflow of that rock. 



The following description of the more important coals is extracted from my 

 Ileport to the Chinese Government, which is published in the "United States Diplo- 

 matic Correspondence, 1864, Part III." 



For more perfect analyses of some of these and other coals by Mr. J. A. Mac- 

 donald, the reader is referred to Appendix No. 2. 



Principal Mines. — The Futau mine, which lies about five li (less than two miles) 

 S. S. E. of Chaitang, and from one hundred and fifty to two hundred feet above 

 the level of the creek at that town, is remarkable as producing a " steam coal" that 

 is equal if not superior to the best Welsh variety. 



The seam, in which several openings have been made, is irregidar in thickness, 

 this varying from six to twelve feet, though in the mean averaging, probably, not 

 less than seven feet. Near the roof the coal has a tendency to crumble, near the 

 floor it is slaty; all the rest of the seam furnishes large blocks of firm and excellent 

 fuel. 



The coal has a brilliant lustre, is made up of well-defined layers, and has a tendency 

 to a cubical fracture. It ignites quickly, burning with a long flame and little smoke. 



