STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. ]65 



deposits within Michigan and Wisconsin, where Thuja occidenfalis 

 (white cedar), Larix laricina (tamarack) and Picea luariana (black 

 spruce) abound, the Thuja being predominant. The growth is so 

 dense that only a thin mat of mosses, liverworts and lichens with an 

 occasional herbaceous plant can grow on the ground beneath. The 

 peat, on which the forest stands, consists of logs and branches, 

 lying in all directions, much changed and more or less macerated. 

 The interstices are filled with " debris, in which macerated parts of 

 stems and branches, cone scales, leaves, thalli of mosses and liver- 

 worts, pollen grains, etc., are plainly recognizable. 



Nothing of algal origin was found in these coals. 



The important coals of Eocene age on the Pacific coast are those 

 in the state of Washington, where one finds all types of coal from 

 peat-like lignite to hard dry anthracite, passing into graphite. Much 

 of the area was studied years ago by B. Willis and G. O. Smith; but 

 since their examination, mining operations have been developed on a 

 large scale at many places, so that it seems best to utilize in this 

 synopsis only the latest results. "^° 



The Cowlitz River, rising in southern Lewis county, flows across 

 Cowlitz county to the Columbia. The coal in this area is lignite 

 throughout except where changed by eruptive rocks. At one locality. 

 Collier saw a bed, more than 20 feet thick, as exposed in two open 

 cuts, and composed of material " apparently little better than peat." 

 It contains fragments of wood, which, though brittle, are flexible 

 and elastic. Similar coal was seen in Lewis county, six miles away 

 toward the northwest. The wood is so well preserved that one can 

 whittle it easily. This fuel has little ash and is given to spontaneous 

 combustion. Throughout the area, the coal is so woody that mining 

 is difficult. 



Some anthracite has been found on the eastern side of Lewis 

 county, but most of the coal in that area is semi-anthracite to semi- 

 bituminous : the beds are thin and the ash is high. At about 30 miles 



230 E. E. Smith, " Coals of the State of Washington," U. S. Geol. Survey, 

 Bull. 274, 191 1, pp. 152, 158, 161, 167, 180, 190; G. W. Evans, "Coals of King 

 County, Washington," Washington Geol. Surv., Bull. 3, 1912, pp. 28, 29, 31-33, 

 59, 65, 116, 152; A. J. Collier, "Coal Resources of Cowlitz River Valley," 

 U. S. Geol. Survey, Bull. 531 L, 1913, pp. 9, 12. 



