432 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



roof of the Juni seams. Cannel-shale and sphserosiderite are char- 

 acteristic and several marine horizons were observed. 



Petrascheck^^ has called attention to the occurrence of coal peb- 

 bles in a sandstone at Brzescze in the Galician area. This sand- 

 stone, containing many fragments of Sigillaria, is shown in the 

 Andreas shaft and belongs to the Upper Schatzlar [Saarbriick]. 

 This sandstone for the most part is moderately coarse, but, where 

 the pebbles of coal occur, the grain is coarser, almost conglomerate. 

 Many of the coal fragments are well rounded, others have rounded 

 angles while in others the edges are still sharp. Along with these 

 are streaks of coal, insignificant in extent, and fragments of shale 

 were seen. The lamination of the coal pebbles does not coincide 

 with that of the sandstone. The largest pebble seen measured 6 

 by 5 by 3 centimeters. 



The fragments include glance and laminated coal as well as 

 cannel and show the peculiarities of each type; glance fragments 

 are sharply angular but those of cannel and laminated coal are more 

 or less rounded. Petrascheck is convinced by the form and struc- 

 ture that these were not balls of peat or pieces of wood, when en- 

 tombed. For him, the evidence indicates clearly that the several 

 types of coal seen in the pebbles had attained their characteristic 

 features in Carboniferous time. The fragments are unquestion- 

 ably of Canboniferous age for no older coal-bearing series exists 

 anywhere in the surrounding region ; but the source has not been 

 discovered. 



The Lower Silesian-B oJieniian Basin. — One reaches this basin at 

 about 150 miles north of west from the Upper Silesian field. The 

 area is not far from 750 square miles ; originally it was open toward 

 the southeast, but was closed at the north and west by the Riesenge- 

 birge and at the east by the Eulengebirge. The northwestern and 

 eastern portions are in Silesia but the southwestern, including much 

 of the interior basin, is in Bohemia. The region was studied in 

 great detail by Goeppert and recently Dannenberg^° has summarized 



29 W. Petrascheck, " Das Vorkommen von Steinkohlengerollen in einem 

 Karbonsandstein Galiziens," Verh. k. k. Geol. Reichsan, 1910, pp. 380-386. 



30 H. R. Goeppert, " Abhandlung, etc.," 1848, pp. 207-275 ; A. Dannen- 

 berg, " Geologic der Steinkohlenlager," 1908, pp. 147-184. 



