280 STEATIGRAPHICAL GEOLOGY 



probably 3000 feet thick, and a few fossils (Phillipsia and Productus) 

 have been found in lenticles of limestone near the top. In the 

 basin of Laval there is a more massive black limestone containing 

 Productus giganteus and other Visean species, overlain by shales, 

 coal-seams, and sandstones with 'plant remains (Bornia transitionis, 

 etc.), and in the centre of the basin is a band of red and green 

 limestone. 



Only the plant-bearing beds pass into the basin of Ancenis and 

 the Basse Loire district, but these are more than 3000 feet thick, 

 consisting of shales and sandstones with many beds of anthracitic 

 coal. The plants are those mentioned on p. 245. 



From the above account it will be seen that the Tournaisian 

 does not appear to be represented, except perhaps by conglomerates 

 and lavas. The greater part of the series belongs to the Visean, and 

 the place of the Yoredale Beds is taken by a group of lagunic and 

 estuarine deposits. 



2. Germany 



East of the Rhine in Germany a very different facies prevails, 

 which has long been known as that of the Culm. This consists of 

 a thick series of shales and sandstones ; limestones only occurring as 

 lenticular beds or as layers of calcareous nodules. The series is 

 generally divided into a lower and an upper group, the lower 

 being essentially marine, while the higher seldom contains anything 

 but plant remains. In Westphalia, Hesse, and Nassau the Lower 

 Culm has at the base chert-beds and siliceous limestones about 200 

 feet thick, containing Prolecanites compressus, Pronorites cyclolobus, 

 and Orthoceras striolatum ; the overlying beds are dark thin-bedded 

 limestones containing Glyphioceras spTuericum and G. crenistria, 

 with Productus giganteus and Ghonetes papillionaceus. Above this 

 are shales abounding in Posidonomya Becheri, and the total thick- 

 ness is about 1400 feet. The Upper Culm consists of coarser sand- 

 stones, often pebbly, and contains the characteristic plants Knorria 

 imbricata, Bornia transitionis, Lepidodendron veltheimianum. 



This Culm facies is found also in the Harz Mountains, Thuringia, 

 the Fichtelgebirge, and over a large area in Saxony. It likewise 

 occupies parts of Silesia and Moravia, where it is of great thickness 

 and has a somewhat different facies. According to Stur, the 

 Silesian succession is as follows : 



Shales with plant remains. 



Sandstones and shales with Posidonomya Becheri, Glyphioceras sphceri- 



cum, etc. , and other beds with plants. 

 Sandstones, shales, and conglomerates with both marine and terrestrial 



fossils. 



