ANTHRACITE OF OTHER REGIONS. 47 



Lower division : 



Numbers 24 23 26 22 25 21 27 



Miles 40 42 50 51 56 70 72 



Despite these anomalies, which tell us that ninch remains to be learned 

 respecting the variations in these coals, there can be no doubt that the 

 proportion of volatile is less at the east than at the west, and the contrast 

 becomes more marked if the comparison be made with the western exten- 

 sion of this field in Indian territory, for there the percentage of volatile 

 rises to 30, giving a fuel ratio of 2.11, whereas the lowest ratio given by 

 Mr Winslow for Arkansas is 3.51. 



]\Ir Winslow calls attention to the fact that the decrease in volatile is 

 in the direction of decreasing disturbance in the rocks ; that in the 

 western counties there is a system of flexures recalling the Pennsylvania 

 conditions, but no such system exists in the anthracitic counties where 

 " there are very few folds of any kind and a nearly horizontal stratigraphy 

 characterizes the coal areas." 



Anthracite Field of Donetz, Russia. 



A brief reference may be made to the antliracite field in southern 

 Russia west from the Donetz river which Murchison^-^ has described. If 

 one follow any of the zones along the strike from the tracts where lime- 

 stone abounds, he finds the calcareous matter thinning out toward the 

 east, and with this alteration comes a great decrease in the " carbonaceous 

 matter," the bituminous coal disappearing and its place being taken by 

 anthracite. In proceeding from north by west to south by east through 

 the hilly steppes north from Novo Tscherkash one finds the limestone 

 thinning out to insignificant bands, while the sandstones and shales 

 become hard. With these changes in the associated rocks the coal seams 

 become less and less bituminous until they assume all the characters of 

 pure antliracite. 



Murchison notes that the line of the anthracite coal coincides with 

 that of the crystalline axis of the southern steppes. 



Variation in the volatile Combustibles in Pennsylvania Coals. 



The apparent law of variation in volatile combustible material so 

 attracted the attention of Pennsylvania geologists that efforts have been 

 made more than once to formulate a satisfactor}^ hypothesis, accounting 

 not for the origin of anthracite as such, but for the origin of the Penn- 

 sylvania anthracite, associated, as it is, with all intermediate grades and 



*Mui'ehi.son : Geology of Russia and tlie Ural Mountains, vol. i, pp. 100, 101. 

 Vn-Bui,r.. Gkoi,. Soc. Am., Voi,. 5. 1893. 



