128 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



but the analysis of an air-dried specimen by R. J. Moss as given on 

 p. 563 of the volume just cited, shows for it a composition not far 

 from that of a well-advanced bituminous coal: Water, 2.01; ash, 

 8.49; carbon, 82.97; hydrogen, 6.15 ; oxygen and nitrogen, 10.87. 



The coal beds of Trinidad,^'^ in the West Indies, are part of a 

 deposit originally continuous southward in Venezuela, where it under- 

 lies an area of not less than 36,000 square miles. This region lies 

 south from N. L. 10 degrees, where the climate during the Miocene 

 was intensely tropical, as it still is. The newer Parian group has a 

 fauna allied to that of the Miocene and the coal beds are in the lower 

 members, the Caroni and the Moruga. Those of the former, from 

 mere films to 4 feet 6 inches thick, are well shown in the interior 

 where the upper beds, with dip of 15 degrees, are distinctly ligneous, 

 but the lower beds, with dip of 40 to 50 degrees, are, to the naked 

 eye, structureless. No roots were recognized in the underclays. The 

 Moruga beds are not important ; frequently they are little better than 

 carbonaceous shale. At two places, roots were seen " rectangular to 

 the bases of the strata." The accompanying rocks in both divisions 

 are chiefly shales, but the Caroni contains a thick sandstone with 

 ripple-marked surfaces. 



Returning to the north, important deposits of coaP' ' have been 

 opened in the Miocene on Advent Bay. The bed is triple at 60 yards 

 from the crop, showing coal, i foot 8 inches, clay, 2 to 4 inches, coal, 

 I foot 7 inches, sand, 3 to 5 inches, coal, i foot. 



In the upper benches the coal is hard, grayish-black, imperfectly 

 laminated and with a somewhat conchoidal fracture. The bottom 

 bench is black, laminated, rather lustrous and tends to be prismatic. 

 Mineral charcoal is present in considerable quantity. In general ap- 

 pearance, coal from the upper benches is mostly splint-like but that 

 from the lowest bench is remarkably like ordinary bituminous coal. 

 Air-dried specimens contain less than 5 per cent, of water. Caustic 

 potash solution attacks the coal throughout and acquires a very in- 



1"*^ G. P. Wall and J. G. Sawkins, " Report on the Geology of Trinidad," 

 London, i860, pp. 41-50. 



1"^ J. J. Stevenson, " The Jurassic Coal of Spitzbergen," Ann. N. Y. Acad. 

 Sci., Vol. XII., 1895, pp. 82-95. The assignment of this coal to the Jurassic 

 is an error; Nathorst has shown that it is Miocene. 



