older Deposits of the North of Germany and Belgium. 235 



have before alluded. We may however remark in this place, that beds which we 

 consider (from their position in the undisturbed sections as well as from their 

 fossils) to represent the base of the carboniferous system, have, on account of their 

 mineral characters, been merged by many German geologists with the older grau- 

 wacke. The result has been, that in their published tables certain fossils of the 

 carboniferous strata have been placed below, instead of above, the fossils of the 

 great Westphalian limestone ; which, as we now proceed to show, occupies a 

 position intermediate between the carboniferous and the Silurian system. 



Groups below the Carboniferous System. 



Devonian Rocks (Map, PI. XXIV. colour 7, and PL XXIII. Sections 3 and 4, 



colours e and/.) 



We now proceed to consider the strata beneath the formation which represents 

 the base of the carboniferous system of Great Britain. In their long range from 

 a point north of Elberfeldt to the acute angle east of Arnsberg (where the beds 

 are suddenly deflected to the south-west), the lower calcareous shales beneath the 

 kiesel schiefer contain some peculiar reddish strata, made up of small concretions 

 of impure limestone imbedded in a red shale. As these shales contain the Posi- 

 donia and some other fossils of the upper beds, we regard them as the base of the 

 overlying system. 



These strata are succeeded by psammitic flagstones, which near Schelke and at 

 Hemer, east of Iserlohn, form a well-marked and persistent feature. Other shales 

 of blackish colours rise out from beneath the psammites, and in them are courses of 

 impure limestone ; in which, together with flattened Goniatites, we begin to observe 

 fossil shells of species unknown in the overlying formation ; such, for example, 

 as the very characteristic fossil {Terebratula aspera, Schloth.). These beds may 

 therefore be considered as forming the commencement of another system, distinct 

 from the carboniferous. We conceive that the psammites and shales are the 

 equivalents of our upper group of the older strata of Devonshire, immediately 

 under the culm measures*, and we shall insist further on the relations of these 

 highest strata of our present group, when we describe the Belgian series, in which 

 they are much more expanded than in Westphaliaf . 



Limestone and Shale. {Limestone of Mettmann, Elberfeldt, Hagen, Iserlohn, S^c.) 



The psammite and shale below the carboniferous system, in w^hich we first ob- 

 serve fossils of new forms, constitute a passage into a lower calcareous system, 



* See Geol. Trans, vol. v. pp. GiS, 647. 



f See PI. XXIII. Sect. 4 and 12 ; also the tabular or general section 1, letter e. 



