Nor 5.] BAWSON — LIGNITE FORMATIONS. 251 



horizontal attitude and easy accessibility, and could probably be 

 mined by a system similar to that known as long wall, at the 

 expense of a comparatively small amount of mine timber, which 

 in these woodless regions would be a great advantage. The 

 iron-stones, though occurring frequently in proximity to the 

 coals, have not yet been observed in workable quantity, but it 

 is highly probable that further explorations may bring such 

 localities to light. The ores are among the best of their kind, 

 both as to percentage of iron and freedom from sulphur and 

 phosphorus. None of the lignites yet discovered yield however 

 a coherent coke suitable for the smelting of iron in the blast 

 furnace.^ 



The conditions implied by the nature of these deposits are 

 marshes, lakes and estuaries, on a grand scale, and from which 

 the sea was for the greater part of the time excluded. The 

 ■previous deposits of Cretaceous age show that at that time the 

 whole western part of the continent was covered by a sea of 

 some depth, in which during a long time before the advent of 

 the lignite period, fine silty and muddy sediments were laid 

 «lowly down, and included the remains of Ceplialopoda and 

 LamelUhrancliiata peculiar to that age. Then came on a period 

 of emergence, coarser sediments were carried by the waters, and 

 at last the sea was entirely shut off from the area in question 

 and replaced by great lakes of fresh water, with wide swampy 

 margins, where the lignites were slowly formed by the growth o( 

 trees and peaty moss. 



Much question has lately arisen with regard to the true age 

 of the representatives of these deposits in the Western States. 

 The plants as compared with those of European formations, have 

 a comparatively modern aspect, and were originally referred on 

 good authority to the Miocene. The molluscous fossils occur- 

 ring in marine beds connected with the base of the formation on 

 its western margin, show Cretaceous affinities. Cope maintains 

 that the Cretaceous age of the greater part, if not the whole of 

 the formation, is proved by the existence in it of a few relics of 

 Pinosaurian reptiles. It would seem indeed that in the regular 

 passage of beds of well marked Cretaceous age upwards into the 

 Lignite Tertiary formation, we have a case of the blending of 



* Mr. Miller, in some remarks made after the reading of thin paper, 

 mentioned the successful employment of charcoal made from similar 

 lignites in Germany, in iron smelting. 



