130 GEOLOGICAL RECONNOISSANCE 



The shale that forms the roof of the coal, is considerably indurated and 

 of an argillo-siliceous composition, with disseminated scales of mica, and 

 includes segregations of a material not very different from its matrix, but 

 harder and heavier. Some obscure stems and long slender leaves or 

 glumes of some plant can be discovered, by splitting up the shale ; but 

 their specific and even generic characters are difficult to make out. The 

 dark shales, forming the roof of this coal, are visible in sections at several 

 bends of Spadra creek, for more than a mile above its mouth. From the 

 dip of the rock, there is no doubt that this coal could be reached by shafts 

 of reasonable depth, sunk in or near the town of Clarksville. 



The character of this coal is worthy of especial notice. The approximate 

 chemical analysis here given shows it to be a semi-anthracite, rich in carbon, 

 and containing a small proportion of ochre-colored ashes ; with only 8.4 

 per cent, of volatile matter, including moisture expelled at 300 deg. of 

 Fahrenheit's thermometer. Its specific gravity is 1.335. 



The approximate analysis gives : 



Tr , .., , . o a j Moisture, 0.5 



Volatile matters, 8.4 j y olatile combustible gases, . 7.9 



_, 1 01(1 f Fixed carbon, 85.6 



Coke > yi>b \ Ashes (ochre yellow), ... 6.0 



100.0 100.0 



This coal contains a far higher per centage of fixed carbon than any 

 western coal that has ever been analyzed in my laboratory, except some 

 coals* which I received from Arkansas some years before the commence- 

 ment of the survey. 



In this respect, the Spadra coal resembles the coals of the Shamokin 

 basin, of Pennsylvania ; especially the Zerbe's run semi-anthracite ; con- 

 taining, in fact, 1.35 per cent, more fixed carbon than that coal, and nearly 

 1 per cent, less ashes. Its gaseous matter is chiefly hydrogen, as its 

 luminous property is so feeble as hardly to be distinguishable by daylight, 

 when this coal is exposed to a red heat in an open spoon. The existence 

 of a semi-anthracite coal in the west is the more surprising, since the for- 



* One of the specimens of coal was said to be from White county, and most probably from the 

 bed mentioned in the section of that county. It had a specific gravity of 1.39, and gave by analysis: 



Volatile matters, including moisture, 10 



Fixed carbon in coke, ^" 



Ashes, ^ 



100 

 Another speciman, said to be from the Petite Jean mountain, yielded : 



Volatile matters, including moisture, 8.5 



Coke, including ashes, 91-5 



100.0 



