194 GEOLOGICAL SURVEY OF THE TEERITORIES. 



are exposed in many localities all along the eastern base of the mountains, and from 

 the best information I can secure, I have estimated the area occupied by them north of 

 the Arkansas River at five thousand square miles. According to the explorations of Dr. 

 John L. LeContc duriug the past season, which are of great interest, these same lignite 

 formations extend far southward into New Mexico on both sides of the Rocky Mountains. 

 Specimens of lignite brought from the Raton Mountains by^Dr. LeConte, resemble very 

 closely in appearance and color the anthracites of Pennsylvania. It is probable that no 

 true coal will ever be found west of longitude ninety-six degrees, and it becomes there- 

 fore a most important question to ascertain the real value of these vast deposits of lig- 

 nite for fuel and other economical purposes. Can these lignites be employed for gen- 

 erating steam and smelting ores ? In regard to the lignites in the Laramie Plains, I 

 have as yet seen no analysis, but specimens are now in the hands of Dr. Torrej^, of New 

 York, for that purpose ; specnnens from Marshall's mine on South Boulder Creek were 

 submitted to Dr. Torrey by the Union Pacific Railroad Companvfor examination witli 

 the following result : 



Water in a state of combination, or its elements 12. 00 



Volatile matter expelled at a red heat, forming inflammable gases and vapors . . 26. 00 



Fixed carbon 59. 20 



Ash of a reddish color, sometimes gray 2. 80 



WO. 00 



A specimen from Coal Creek, tliree miles south, yielded similar results : 



Water in a state of combination, or probably its elements, as in dry wood 20. 00 



Volatile matter expelled at a red heat in the form of in-flammable gases and 



vajjors 19. 30 



Fixed carbon 58. 70 



Ash, consisting chiefly of oxide of iron, alumina, and a little silica 2. 00 



100. 00 



The percentage of carbon is shown to be in one case 59.20, and in the other 58.70, 

 which shows at a glance the superiority of the western lignites over those found in any 

 other portion of the world. Anthracite is regarded as so much sujierior as a fuel, on 

 account of the large iier cent, of carbon, and also the .small amount of hydrogen and 

 oxygen. The bituminous coals contain a large percentage of hydrogen and oxygen, 

 but not enough water and ash to jtrevent them from being made useful, but the calor- 

 ific power of lignite is very much diminished by the quantity of Avtiter contained in it, 

 from the fact that so valuable a jjortion of the fuel must be used in converting that 

 water into steam. 



The day of my visit to the Marshall coal mines, on South Boulder Creek, seventy- 

 three tons of lignite were taken out and sold at the rate of four dollars a ton at the 

 mine, and from twelve to sixteen dollars at Denver.' This lignite is somewhat brittle, 

 but has nearly the hardness of ordinary anthracite, which it very much resembles at a 

 distance. 



In some portions there is a considerable quantity of resin. I spent two evenings at 

 Mr. Marshall's house, burning this fuel in a furnace, and it seemed to me that it would 

 prove to be superior to ordinary western bituminous coals, and rank next to anthracite 

 for domestic purposes. Being non-bitumiuous, it -svill require a draught to burn well. 

 It is as neat as anthracite, leaving no stain on the fingers. It produces no ofi"eBsive gas 

 or odor, and is thus superior in a sanitary point of view, and when brought into gen- 

 eral use, it will be a great favorite for culinary x^urposes. It contains no destructive 

 elements, leaves very little ash, no clinkers, and produces no more erosive effects on 

 stoves, grates, or steam boilers, than dry wood. If exposed in the open air it is apt 

 to crumble, but if protected it receives no special injury. Dr. Torrey thinks there is 

 no reason why it should not be eminently useful for generating steam and for smelting 

 ores. 



Throughout the intercalated beds of clay at Boulder Creek and vicinity are found 

 masses of a kind of concretionary iron ore, varying in size from one ounce to several 

 tons in weight. This iron ore is probably a limonite commonly known under the name 

 of brown hematite or brown iron ore. It maj^ perhaps bo found in the state of carbonate 

 of iron when sought for, beyond the reach of the atmosphere. These nodules or concre- 

 tionary masses, when broken, show regular concentric rings varying in color from j^el- 

 low to brown, looking sometimes like rusty yellow agates. It is said to yield seventy 

 per cent, of metallic iron. The first smelting furnace ever erected in Colorado was 

 established here by Mr. Marshall, and he informed me that for the i)rod action of one ton 

 of pig iron, three tons of the ore, two hundred pounds of limestone, and one hundred 

 and thirty to one hundred and fifty bushels of charcoal are required. Over five hundred 

 tons of this ore have been taken from this locality, and the area over which it seems to 



