I'EALE. I 



GEOLOGY ANTHRACITE COAL. 



177 



Rock Creek. — The coal on this creek is also an anthracite. It is found 

 in Cretaceous shales beneath a mass of trachyte. The shales represent 

 a horizon at least 3,000 feet above the Dakota group. The bed is 5 feet 

 thick. 



The following is an analysis of the coal. It has a brilliant luster, 

 conchoidal fracture. 



Analysis. 



Water and volatile matters . . . * 7.4 



Carbon 88.92 



Ash, (reddish) 3.68 



100. 00 



The following is an analysis of coal from this region (probably from 

 Eock Creek) by Professor Mallet, of Colorado: 



Fixed carbon 



Ash of dark- brownish color 



Volatile matters, chiefly water 



Analysis. 



91.02 



5.30 



3.68 



100. 00 



The analyses given above show a decided advantage over the lignites 

 found in other parts of the Territory, and their occurrence in the midst 

 of so many deposits of galena, nearly all of which is probably silver- 

 bearing, will probably in the future have a decided and important bear- 

 ing upon the mining operations that may be carried on in this region. 

 The following table gives the comparison of average percentages of con- 

 stituents of the Elk Mountain coals with those of anthracites and other 

 varieties^ of both foreign and domestic. It will be seen that the coals 

 of which analyses have been given above rank high in the comparison. 





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Carbon. 



Ash. 





Variety. 



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Remarks. 



Foreign anthracites.. 



3. 537+ 



92.56 



87.96 



90.49 



9.31 



1.58 



5.935 



4 analyses, taken from Dana's 

 Mineralogy; localities, South 

 Wales and Hanover. 



Pennsylvania anthra- 

 cites. 



5.811 



94.10 



80.57 



88. 046 



9.25 



2.90 



5.348 



7 analyses, from table in Rogers's 

 Geological Survey of Pennsyl- 

 vania, volume ii, part ii. 



Pennsylvania semi- 

 anthracites. 



10. 106 



90.23 



74.55 



82. 070 



12.30 



2.70 



7. 661 



10 analyses, from table in Rog- 

 ers's Geological Survey of 

 Pennsylvania, vol. ii, part ii. 



Anthracites from the 

 Elk Mountains, 

 Colorado Territory. 



7.726 



91.90 



74.00 



86.804 



8.00 



3.68 



5.476 



Result or 5 analyses given 

 above in the chapter preced- 

 ing this table. 



Pennsylvania bitu- 

 minous coals. 



28.222 



70.68 



56.80 



71. 756 



11.75 



2.07 



5. 762 



10 analyses, from table in Rog- 

 ers's Geological Survey of 

 Pennsylvania, vol. ii, part ii. 



Foreign bituminous. . 







89.27 



75.59 



81. 126 



8.60 



1.41 



.3.694 



10 analyses, taken from Dana's 

 Mineralogy. 





36.65 



64.20 



53.50 



58.10 



13.00 



1.80 



5.12 



20 analyses, from Newberry's 

 Geological Report of Survey 

 of Ohio for 1873. 





Indiana coals 



42.21 



59.00 



43. 50 



51.20 



18.50 



-2.09 



6.02 



52 analyses, from Geological Re- 

 port of Survey of Indiana for 

 1873. 



12 H 



