60 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



watered and covered with a dense forest of fir. On the border of 

 the dune, the sand covered part of a peat-moor, where it had stopped 

 growth while accumulation continued unchecked on the uncovered 

 portion. Peat from the latter does not differ from that of bogs 

 in the neighborhood, but that from the sand-covered portion has 

 been changed into a wholly different substance. Ordinary Moor- 

 tor f, dried, weighs from 1 6 to 20 pounds per cubic foot, but that 

 which has been compressed by the dune weighs 78 pounds. In 

 ordinary peat, dried, one finds scarcely any trace of layers, but this 

 compressed peat is almost shale-like in lamination. The Seeland 

 peat is formed mostly of offal from a forest vegetation, but in hand 

 specimens one cannot distinguish it from brown coal. 



V. Giimbel in 1883 found that the Martorv has alternating bright 

 and dull laminae, the bright portions consisting chiefly of ribs and 

 hard parts of grass leaves with admixture of other parts, pollen, 

 etc. He thought that it bears much resemblance to Lebertorf, but 

 it is clearly of different origin. One would surmise from the condi- 

 tions that this Martorv contains both mature and immature peat. 

 The observations by Jentzsch are confirmatory. He remarks that 

 the Martorv found near Rixhoft in East Prussia is derived without 

 doubt from the Bielawe and other moors, that it is compressed 

 material from underneath the dunes, which now separate those 

 moors. Nilson"^ has described a vast gravel deposit which follows 

 the Baltic coast of Sweden for a long distance beyond Ystad and, 

 at various places, rests on peat. 

 This material is similar in composition to the recent peat of Sweden. 



Lesquereux's'^'' description of conditions in the valley of the 

 Locle in Switzerland is equally to the point. On the side of the 

 valley, under a heavy bed of marl, he found 3 inches of compressed 

 material, hard, fragile and with brilliant fracture ; lower down the 

 slope, where the marl is but 4 feet thick now, the deposit is 6 to 



69 Nilson, cited by J. Geikie, " Prehistoric Europe," p. 473. 



" The peat under this stone wall is so compressed that, when dry, it is 

 almost as hard as brown coal ; the trees also are, like the layers of coal, 

 pressed together, and when a fir chip is broken, it is found to be black and 

 shining in the cross-section, all the result of great pressure and age." 



■^0 L. Lesquereux, " Quelques recherches sur les marais tourbeux," Mem. 

 Soc. Sci. Nat. Ncuchatd, Vol. III., 1845, pp. 95, 127. 



