454 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



rudely triangular, about 20 kilometers wide on the Saar River and 

 diminishing northeastwardly to 10 kilometers at a little way beyond 

 Neukirchen, 50 kilometers from the Saar. The extreme distance, 

 along which the coal is accessible, is barely 100 kilometers, extend- 

 ing from beyond the eastern border of Lorraine across the narrow 

 strip of Prussia into the Rheinpfalz of Bavaria. The field has been 

 described more or less in detail by many students, but use will be 

 made here only of works by Nasse,*° v. Ammon and Dannenberg. 

 Nasse and Dannenberg have discussed the whole basin, while v. 

 Ammon has described in detail the Bavarian field, which embraces 

 the greater part of the available area. 



The deposits occupy a trough, much distorted, which is cut off 

 abruptly at the south by the siidliche Hauptsprung, a downthrow of 

 not less than 1,000 meters. Only Permian and Carboniferous rocks 

 have been found within the trough, but Bunter Sandstein is present 

 just beyond the immediate area. The lowest beds reached by bor- 

 ings are Saarbriickian, which are succeeded by Ottweiler and Roth- 

 liegende in conformable order, so that the whole may be termed the 

 Permo-Carbonif erous system ; but in the extreme western portion, 

 within France, there is unconformity, for there Rothliegende rests 

 on disturbed Saarbriickian beds. The latest classification is Roth- 

 liegende, Upper, in four divisions, of which the Lebacher beds are 

 the lowest. This contains plants, Estheria, reptiles, fishes and 

 worthless streaks of coal. Lower, the Kuseler beds, contain- 

 ing similar fossils, some calcareous beds and streaks of coal. 

 Upper Carboniferous, 



Ottweiler beds. Upper, containing fish remains, etc., with Breit- 

 enbach coal bed. Middle, or Potzburg beds, with some cal- 

 careous beds, Leaia, Cardinia and the Hirteler coal seams. 

 Lower, the Hangende Flotzzug, fossils as in Middle ; Holzer 

 Conglomerate at base. 

 SaarbriJck beds. Upper or Flammekohlen Gruppe, Lower or 

 Fettkohlen Gruppe. 



•*^ R. Nasse, " Geologische Skizze des Saarbriicker Steinkohlengebirge," 

 Zeitsch. Berg-hutten-Salinen-wescn im Preuss., Band 32, 1884, Abh., pp. 1-89 ; 

 L. V. Ammon, " Die Steinkohlenformation in den Bayerischen Rheinfalz," 

 Miinchen, 1903, pp. 1-106; A. Dannenberg, " Geologie der Steinkohlenlager," 

 pp. 10S-165. 



