STEVENSON— INTERRELATIONS OF FOSSIL FUELS- 127 



groundmass. The darker resins are deep brown in color and in 

 general are opaquely glassy. The lighter resins are in striking con- 

 trast and tend to be more irregular in form. Besides charred cell 

 fragments, few other bodies are present and none of them is in rec- 

 ognizable condition. In variety of constituents, this coal is very 

 simple and thus approaches Paleozoic cannel very closely. It is so 

 brittle that proper sections cannot be prepared. The analysis 

 showed 67.61 of volatile matter and 32.39 per cent, of fixed carbon 

 in the pure coal. The cannel is overlain by a thin bituminous bench, 

 which has 60 per cent, of volatile to 40 of fixed carbon, making 

 probable that the upper bench contains much spore material. 



Cannel is said to be present in the Lakota sandstone of the 

 Black Hills, at a Kootenai horizon, where it is in two benches, each 

 about a foot and a half thick and overlain by bituminous coal. 

 The proximate analysis suggests that this is more probably a bony 

 coal, as the volatile is but 38.64 and the fixed carbon 61.46 per cent, 

 in the pure coal ; the ash is 24.16. Cannel is present in the Kootenai 

 of the Elk River district of Alberta, the composition being 65.55 o^ 

 volatile and 34.45 of fixed carbon ; the ash is only 9.86 per cent."^ 



That coals of very different types may occur in the same vertical 

 section is evident from conditions in the Wealden of Hannover. 

 Dunker^^^ states that in many localities the coal resembles the older 

 black coals, there being no trace of woody structure and the streak 

 is blackish brown. This type of coal was analyzed by Regnault ; 

 but lignite is present also, which preserves the woody structure 

 and has reddish brown streak. A sample from Helmstadt was 

 analyzed by Varrentrapp. The results are : 



Beside these there is the Blatterkohle, composed of leaves and twigs 

 of conifers and cycads, which is so little changed that the leaves 

 become flexible when soaked in water. This type occurs in the same 



131 U. S. Bureau of Mines, Bull. 22, 1913, p. 194; D. B. Dowling, Geol. 

 Survey of Canada, Memoir 53, 1914, p. 74. 



132 \Y Dunker, " Monographie," etc., p. xiii. 



