STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 23 



the Trias of Aveyron and Herault, states that the abundant coaly 

 impressions of plants in Keuper beds had induced many to search 

 for coal but without success. Grand'Eury saw some coal in the 

 Keuper of Nice which contains stems of Equisetites and in the shale 

 are rootlets of these plants. At Gemmalaincourt, he found Equise- 

 tites roots in the underclay but bark and seeds are in the coal. 



Germany. — The Lower or Kohlenkeuper contains at many places 

 in Germany the Lettenkohle, which Credner'- describes as a car- 

 bonaceous clay, filled with plant remains and at times passing into 

 impure coal. Near Siwierz in Poland there are 3 beds 30, 50 and 

 80 inches thick. Sandberger^' published records of numerous sec- 

 tions of Triassic deposits obtained in Unterfranken of Bavaria. He 

 offers no comments, but the records suffice to prove irregularity of 

 deposit. Two Lettenkohle sections " near Wiirzburg exhibit the 

 triple structure. That obtained between ^Wiirzburg and Rothen- 

 dorf shows at top of the middle division a yellow fine-grained sand- 

 stone with many erect roots, while at base of the division is a zone 

 with abundant remains of plants. This rests on the Hauptsand- 

 stein of the lower division, part of which is diagonally bedded. No 

 coal is present. In the other section, between Wiirzburg and 

 Schweinfurt, plant remains abound in both the upper and the 

 middle division, but coal is wanting ; the top layer of the Hauptsand- 

 stein is argillaceous sandstone with many roots, while at the base is 

 a fine-grained sandstone with irregular layers of pulverulent coal. 

 A section of the Krainberg gives these details respecting the middle 

 division: (i) clay shale, with Lettenkohle at base, 3.66; (2) shale, 

 0.15; (3) sandstone with roots, 1.18; (4) clay shale, 1.18; (5) 

 Lettenkohle and plants, 0.70; (6) ochreous limestone, 1.32; below 

 which to the base are sandstone, ochreous limestone, clay shale and 

 sandy shale, all apparently without coal. The sandstone, No. 3, is 

 the root bed for plants which produced the impure coal above it. 



The conditions seem to have been much the same at all localities 

 where Lettenkohle exists. The coal is irregular in occurrence and 



22 H. Credner, " Elemente der Geologic," 8te Aufl., 1897, p. 535. 



33 F. V. Sandberger, " Die Lagerung des Muschelkalk- und Lettenkohlen 

 Gruppe in Unterfranken," Verh. Phys. Med. Gesells. Wiirzburg, Band XXVL, 

 1893. PP- 200, 205, 206. 



