older Deposits of the North of Germany and Belgium. 247 



Although, this arrangement exists in the immediate neighbourhood of Oberscheld, 

 we do not think it can he laid down as general. In fact, even in this tract 

 there are strong calcareous courses of the same formation which are quite subor- 

 dinate to schaalstein, and others which are unaltered are included in shales. The 

 masses therefore which are associated with the greenstone ought not to be regarded 

 as a distinct formation, but rather as altered ferriferous portions of a complicated 

 group, with many different arrangements of its subordinate parts. 



The mere list of fossils given by M. Beyrich supports our opinion, that these 

 limestones constitute a member of the Devonian system. After mentioning the 

 Ammonites (Goniatites) Becheri, Goldf., Encrinites, Caryophyllia, Orthoceratites, and 

 Trilobites, he dwells particularly on the fact, that the Goniatites are so various and 

 so abundant that the rock might be termed a goniatite limestone*. 



But M. Beyrich is, we think, in error when he supposes that certain limestones 

 of the Fichtelgebirge described by Count Miinster, and to which we shall hereafter 

 advert, cannot be of the same age as those of Oberscheld and Dillenburg, be- 

 cause the latter are charged with Goniatites and the former with Clymenice ; for the 

 very rocks described by Count Miinster contain both these genera. 



Copper Mines near Dillenburg . 



The slates of Wissenbach and the underlying grauwacke will be described under 

 the head of Silurian Rocks. Before, however, we leave the tract around Dillen- 

 burg, we may say a few words upon its copper-mines, for which it is as much 

 distinguished as for its ores of iron. 



According to the miners (and our friend M. Erbreich had given us similar information respecting the 

 mines near Brilon), the copper veins traverse all the rocks of the district, being, as in every other 

 country, more productive in one matrix than another. Thus, where we meet with the common unaltered 

 black shale, which is much expanded to the east, the veins cease to be productive, or in miner's language, 

 are " cut oiff." When they enter the " schaalstein " the copper veins are generally productive, particu- 

 larly where this rock contains much calcareous spar ; but they are still richer when they pass through 

 ferriferous strata or beds of iron ore. So uniformly do these relations prevail, that although a tolerably 

 good copper ore is now and then found in a "schaalstein" of green colour, in which chlorite prevails, it 

 suddenly becomes richer where the vein cuts into " schaalstein " which is impregnated with iron. The 

 chief veins strike from N.N.W. or N.W. to S.S.E. and S.E., and the smaller branch veins are oblique to 



but the question seems to be placed beyond a doubt by the fact that the fossils of Oberscheld and Brilon 

 are identical : for the true place of the Brilon limestone admits of no doubt, being the actual prolonga- 

 tion of the great Westphalian limestone. 



* For the peculiar character of these shells, see the observations of MM. d'Archiac and de Verneuil. 



t This rule admits not of any general application in England, though we have observed some striking 

 examples of it. (See the ' Silurian System,' Chapters 22 and 24.) 



2 K 2 



