STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 63 



J. Geikie'- has given numerous instances of submerged deposits 

 on the coast of Scotland. Farther inland, in the Carse lands on both 

 sides of that country, deeply buried deposits have been exposed by 

 the rivers. The River Tay has cut its channel down to a peat bog, 

 now forming the river bed and underlying about 17 feet of alluvial 

 material, which near the top contains cockles, mussels and other 

 marine forms. In some parts of the wide Carse area, this ex- 

 tensive deposit rests on alluvial sands but in others on marine clays. 

 The peat is much compressed and splits readily into laminje, on 

 whose surfaces are small seeds and wing cases of insects. As a 

 rule, it is marked off sharply from the overlying clay and silt, but, 

 at times, it is covered with vegetable debris which was drifted in 

 from places higher up in the valley. Skertchly'^^ found that on the 

 Isle of Ely the peat underlies 4 to 8 feet of silt and clay and rests 

 on clay, both roof and floor being marine, the peat marking an 

 interruption in deposition of the clays. Several peat beds are within 

 12 feet; the lowest, 18 inches thick, is normal, black and clean; but 

 the higher peats are irregular and impure, mingled with clay, show- 

 ing the contests between plants and muddy water. Travis^* has 

 described a case of marine association, which shows also a by no 

 means unusual relation of the beds. The Seaforth Dock excava- 

 tion, 40 feet deep, 180 wide and 900 long, exposes two beds of 

 peat. The lower, 18 to 24 inches thick, rests on gray sand and is 

 shown for about 280 feet. At 5 to 10 feet higher, the interval 

 being filled with Strohicularia clay, is the upper bed, 12 inches thick, 

 which is exposed for 480 feet. It overlaps the lower one. which 

 thins out. The peat in both bands is firm, woody, with occasional 

 fragments of bark and twigs, but it contains no stumps or trunks of 

 trees. 



Lorie has recorded a great number of borings in Holland, which 

 illustrate the succession of buried peat beds, separated by sands 

 deposited beneath the sea. Rutot has given records showing peat 

 beds intercalated in marine sediments on the coast of Belgium. 



^2 J. Geikie, " The Great Ice Age," 1895, pp. 290-293. 

 ■^3 S. B. J. Skertchly, " Fenland," pp. 140-143. 



^* C. B. Travis, " Geological Notes on Recent Dock Excavations at Liver- 

 pool and Birkenhead," Proc. Liv. Geol. Soc, Vol. XL, 1913, pp. 237-275. 



