STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 67 



gravels and brick-clay, the latter containing freshwater shells, frag- 

 ments of wood and paleolithic implements. These facts presented by 

 Reid show that the peat has been converted by pressure into a lignite- 

 like substance; the growth of the swamp was checked and the peat 

 may have been exposed during the considerable period of changing 

 climate, which led to the introduction of a subarctic flora. Direct 

 superposition and conformability are certainly not evidence of con- 

 tinuity of deposition. 



De la Harpe*- saw a bed of peat at Lausanne, Switzerland, one 

 meter and a half thick, underlying gravel and resting on marl. The 

 peat is mixed with marl in the l6west part and the highest part 

 contains some fine micaceous sand. Here and there in the black 

 peat are occasional rock fragments, wholly isolated, as though one 

 had cast them into the soft mass. Seeds, tree stems and branches, 

 altogether decayed, were observed with, here and there in the upper 

 part, a fragment of bark resembling birch. The underlying marl is 

 without pebbles but has abundance of Lyinncca, Vali'ofa, Planorhis, 

 Cyclas and Pisidiiun. 



Keilhack^^ saw a coal deposit near Lauenberg on the Elbe, with 

 these relations, descending: (i) Upper clay, with shells; (2) diluvial 

 sand, 15 meters; (3) coal bed, consisting of (a) fragmentary coal 

 with stems and branches, {b) fruits and leaves, (c) moss; (4) clay; 

 (5) diluvial sand with Cardinm edidc. 



No additional details are given in the abstract. During the dis- 

 cussion, Hauchecorne and Beyrich insisted that the material is not 

 coal but peat. Evidently the change in physical character was suffi- 

 cient to make the relations somewhat doubtful. It is to be noted that 

 the transformation is most advanced in the upper part and that the 

 moss at the bottom appears to have undergone little change. 



The deposits at Klinge, near Kottbus in Brandenburg, have given 

 rise to much discussion as did that at Lauenberg. Keilhack^* ex- 

 amined the great excavation and observed this succession, descend- 



82 Ph. De la Harpe, " Sur un gisement de tourbe glaciaire," Bull. Soc. 

 Vaud. Lausaufie, Vol. XIV., 1877, pp. 456-458. 



83 Keilhack, Zeitsch. d. d. geol. Gesell, Bd. XXXVIL, 1885, p. 549. 



84 H. Keilhack, " Der Alter der Torflager und ihrer Begleitschichten von 

 Klinge bei Kottbus," Zeitsch. d. d. geol. Gesell., Bd. XLIV., 1892, pp. 369-371. 



