310 STRATIGKAPHICAL GEOLOGY 



Teutoburger Wald before they finally rise again to terminate the 

 broad syncline. The student should refer to Stanford's geological 

 map of Central Europe. 



At the base of the series is a thick mass of sandstones (Flotzeere 

 Sandstein), some of which are coarse and pebbly. These beds 

 occupy the place of our Millstone grit and are said to be without 

 fossils. The whole series is believed to be over 11,000 feet thick, 

 and has been divided into the following groups : 



Feet. 



6. Group with highly bituminous coals (35 seams) . . 3000 

 5. ,, less bituminous coals (8 seams) . . 1000 

 4. ,, good coking coals (19 seams) . . . 1200 

 3. ,, fairly good coals (7 seams) . . . 400 

 2. ,, poor coals (21 seams) .... 2500 

 1. The Flotzeere sandstones 3000 



In this siiccession Creiuer has recognised four plant assemblages. 



Zone d = 6, with Neuropteris rarinervis and N. tenuifolia. 



Zone c = 5, with S2)henoj)teris obtusiloba and Lonchopteris. 



Zone 5 = 3 and 4, with Sphen. trifoliata and Alethopteris lonchitica. 



Zone a = 2, with Neuropteris Schlehani. 



It is specially to be noted that though the succession is com- 

 plete, and every part of it seems to be fully developed, the flora 

 of No. 2 (zone a) is not that of our Lower Coal-measures. It 

 contains, however, several bands in which marine fossils occur, the 

 lowest of these being about 600 feet above the base and yielding 

 Gastrioceras Listeri with other species which in England do not 

 range above the lower division. 



2. Belgium and France 



West of the Rhine, a long but rather narrow tract of Carboni- 

 ferous rocks comes in on the north flank of the high ground formed 

 by the Cambrian and Devonian rocks (see p. 216) and stretches 

 continuously from Aix-la-Chapelle by Liege, Namur, and Mons, 

 and thence still farther under the cover of Neozoic deposits by 

 Valenciennes, Douai, and Bethune to the Boulonnais. 



Throughout this tract of country the Carboniferous strata are 

 sharply flexured and much broken by faults. Their southern 

 boundary is generally an overthrust fault with a southerly hade 

 and such a great displacement that the Devonian rocks have been 

 carried over the Coal-measures which are in some places actually 

 worked beneath this cover of older rocks. 



In Belgium the representative of the Millstone grit seems to be 

 very thin, but it forms a constant band of coarse grit from 30 to 



