414 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 4, 



the real bedding are made with difficulty. Another and a still 

 greater impediment to a clear examination of the lie of the strata 

 consists in the dense covering of wood and the rare occurrence of 

 rocks and open ravines. Even in places where the strata are visible, 

 the geologist who is not versed in the lines of cleavage may easily 

 assume that the latter are laminae of deposit. In truth, the native 

 geologists who have treated of these rocks were so deceived, that they 

 were led thereby to represent in their earlier works that which would 

 amount to a total inversion of all the moimtain masses by a dip to 

 the N.W., when in reality the strata (though subject to great undu- 

 lations not represented in our general section) assume a prevalent 

 inclination to the S.E. 



Upper Devonian, — The "younger grauwacke" of this region (so 

 styled by both Creduer and Richter) consists of a union of the 

 sub-groups which we term Upper Devonian and Lower Carboni- 

 ferous. Constituting apparently one physical mass, these formations 

 cover transgressively the Lower Silurian rocks, or abut abruptly 

 against them (see fig. 1, c and d). In travelling across these strata, 

 as exposed in the southernmost portion of the chain, i. e. between 

 Koppelsdorf and Steinach, we found unequivocal Upper Devonian 

 fossils in the higher strata, associated with limestones, and carboni- 

 ferous plants of large size in the younger and more arenaceous 

 deposits. 



In that district, however, the disturbances have been so great 

 (particularly along the banks of the river Steinach), and the strata 

 are there so completely inverted, that M. Engelhardt very naturally 

 represented as Lower Silurian those limestones which from their 

 fossils we now know to be Devonian, and considered the rocks which 

 are truly of that age to be Upper Silurian. 



Passing, however, from that convulsed district, the real relations 

 of the Devonian rocks of the Thiiringerwald are best seen in the 

 environs of Saalfeld, and particularly to the S.E. of that town, where 

 they abut against the Silurian in the gorge of the river Saal. There, 

 as in all the adjacent parts of Saxony extending by Schleitz to Plauen 

 and Hof, there are no equivalents of the Upper Silurian or of the 

 Lower or Middle Devonian. In the absence of the Spirifer-sandstone 

 of the Rhine, and of the limestone of the Eifel, or their equivalents, 

 the limestone, which we are about to describe, and which rests at 

 once on the slaty Lower Silurian, is truly Upper Devonian. 



In the undulating region to the east, which has been mapped by 

 Naumann and his associates and described by Geinitz, the Upper 

 Devonian is much swollen out and distinguished by interpolated 

 sheets of igneous rock, the Schaalstein of the Rhine. On this occa- 

 sion we forbear to enter into a detailed account of such rocks, and 

 will now only speak of the Upper Devonian of Saalfeld, as seen in 

 the cliffs at Bohlen, and the relation of the deposit to the younger 

 strata of the Rotheberg, which we consider to be Lower Carboni- 

 ferous. (See fig. 2.) 



On quitting the grey Silurian, or truly "grauwacke*' region of 

 Saalfeld, and the tracts to the west and south of that town, and in 



