354 



W. H. WEED — COAL FIELDS OF MONTANA. 



mmtm 



7 ft. 



i«« 



-i --^x^-c 



The Coal-Measures and the Workings. — The accompanying figure 1 shows 

 the number and relative position of the workable coal seams at the various 

 openings in this field. As, however, the outcrops of the coal seams are 

 always covered by debris and sand, it is impossible to 

 obtain a perfect section showiug all the seams. 



The sections made at the Horr and Craig mines 

 show three workable seams, and it was noticed that 

 W'hile there is little doubt that the same seams of coal 

 are worked at these two mines, yet the thickness of 

 sandrock between them varies at the two localities. 



Careful measurements made in prospecting the field i .-. ^ -j 180-230' 

 show that the thickness of sandstone between the two 

 upper seams varies from 180 feet to 200 feet. At 

 present, coal is mined at three localities, the Horr 

 mine being the most important. The company con- 

 trolling this mine own the extreme end of the Elec- 

 tric spur. The workings are all in faulted blocks, 

 which was at first supposed to preclude the possibility 

 of successful mining. A large block about a mile 

 wide at the northern end of this ridge has been dropped 

 some 600 feet by a fault, while the extreme end is 

 formed of smaller blocks tilted at various angles. The 

 coal is of excellent quality, however, and makes such 

 fine coke that it has secured a ready market, and 

 considerable mining has been done. 



The oldest opening was in the low^est of the three workable seams, and 

 was mined to the extent of 100 tons a day. A new tunnel is now worked in 

 the northern part of the property, in the same seam, and a considerable out- 

 put comes from a tunnel in the middle main seam (or B). The total output 

 for 1889 was 22,400 tons. It was expected that the output for December 

 (1890) would exceed 250 tons a day. The upper seam has not been mined 

 as yet, though the outcrop has been opened at a few places to ascertain its 

 character. 



The present workings consist of the three tunnels mentioned, the coal 

 being mined by the ordinary methods. 



The sections represented in figure 2, taken at the ends of the tunnels at 

 the different mines, show the character of the lower seam now worked. 



The lowest seam (E, figure 1) found at the Horr workings is about one 

 foot thick. Some 30 feet above it is the lower of the two seams now being 

 worked. Above this seam the sandstone is broken by a layer of intrusive 

 rock, called " whiustone " by the miners, which is about 10 feet thick. Three 

 feet above this layer the baked shale carries fossil leaves. An examination 



3f3ft. 



2/4 ft. 



7n. 

 20' 



Figure 1 — Section of the Cre- 

 taceous Coal-Measures of the 

 Cinnabar Coal Field. 



