older Deposits of the North of Germany and Belgium. 289 



sures of Devon. Near the Frankenhamer Hiitte are thick beds of sandstone with fine Calamites and 

 other vegetable impressions. Some of the great masses of sandstone are separated into rhombohedral 

 blocks by a double set of joints, — one set (strike-Joints) ranging with the beds, though generally dipping 

 to an opposite point of the compass ; the other set (dip-Joints) ranging nearly N.W. and S.E. 



The colours of these sandstones are various — yellowish grey, brown, greenish grey, smoke grey, with 

 small quartz veins, &c. Small spots of kaolin are diffused through some of them ; and among them, 

 not unusually, are seen numberless bright granules of greasy quartz. Beds like these, alternate with 

 slightly micaceous flagstones, and thick beds of dark carbonaceous shale. 



Further down the valley (below the smelting-houses) are beds of a very coarse grit, with granules of 

 greasy quartz as large as peas, like many varieties of millstone grit. These rocks rise into the hills 

 towards Griind, in the direction of which we continued our traverse through a dense forest, which greatly 

 obscured the section. 



We then crossed some beds of dark, indurated, carbonaceous shale, from beneath which rises a very 

 remarkable mass of limestone. Its dip is extremely obscure, some beds being greatly mineralized, broken, 

 fissured, and penetrated by veins of sulphate of barytes ; but as the principal mass ranges through the 

 dense forest in a direction about N.N.E., we presume that it represents the true strike of the beds. This 

 limestone is generally light-coloured and highly crystalline ; and the veins and hollows on its flanks are 

 in some places much charged with iron ore. The whole mass of it, especially in the Hiibigenstein 

 (which rises into bare pyramidal peaks in figure giving a minature resemblance of some of the dolomites 

 of the Alps), is much charged with corals, and in some of the earthy partings of the more crystalline beds 

 or masses are numerous fossil shells. The corals, as a suite, are identical with those of the great lime- 

 stone of Westphalia and the Eifel. Among the shells are 



Spirifer striatulus, so common in the Devonian strata of the Boulonnais. 



glaber. 



Terebratula concentrica (V. Buch), T 



_ , ^ , . ) both good Devonian species. 



lerebratula prisca, J 



Goniatites discors, the same species as at Oberscheld in Nassau. 



Among the shells enumerated by M. Zinchen from this locality were Cardium alceforme (Sowerby), 

 and Terebratula elongata (Schlotheim). 



On the west side of Griind the section is almost entirely concealed ; and the whole series of older 

 rocks is soon afterwards cut off by the terrace of the overlying zechstein. 



From the whole evidence, we have no doubt that the calcareous mass of Griind is a true Devonian 

 limestone ; and that the overlying beds are the equivalents of those parts of the Westphalian sections 

 which extend from the great limestone to the base of the coal-measures. 



We afterwards made a complete traverse from Clausthal by the line of the Innerste ; and though 

 we were unable to make any connected section to determine the order of the successive mineral masses, 

 we saw nothing to invalidate our previous conclusion. 



To the west of the river gorge is a mass of limestone like that of Griind (which, however, we did not 

 examine) ; and in descending the gorge (below the point where we had left it in the previous traverse) we 

 met, first with black carbonaceous shales and grey sandstones; then with grits, shales and psammites,in some 

 places contorted and greatly mineralized. Afterwards, near Lautenthal, we passed singularly contorted 

 masses of Kiesel Schiefer, resembling the rocks before described north of Meschede*; and we after- 

 wards saw specimens of Posidonia obtained from these localities, though we were not fortunate enough 

 to meet with that fossil during our traverse. Still further down the river gorge we met with quarries of a 

 slightly calcareous slate, which we supposed to represent the shales between the Devonian limestone and 



* Ante, p. 232. 



