296 Professor Sedgwick and Mr. Murchison on the 



Stratified Rocks extending from the Thuringerwald, through Upper Franconia, to the 



Fichtelgebirge. 



It formed no part of our original plan to examine the formations between the 

 Thuringerwald and the Fichtelgebirge. But having decided to visit the calcareous 

 deposits on the north flank of the Fichtelgebirge, we thought it most instructive to 

 approach them by a long traverse from the Thuringerwald through all the older rocks 

 of Upper Franconia. 



We entered the country from Weimar by the line of the Saal ; and passing over 

 the successive escarpments of the muschelkalk, bunter sandstein and zechstein 

 (the last of which in several places rests unconformably on the grauwacke without 

 the intervention of any conglomerate), we made our first traverse among the 

 older rocks beyond Schwartzburg by the beautiful gorges of the river Schwartza. 

 We found the slate rocks dipping N.W. ; they alternate with quartzites, and are 

 intersected by dip-joints and strike-joints — the latter generally inclining to a point 

 opposite to the dip of the beds. The cleavage is irregular — sometimes striking 

 with the beds, but at different angles of inclination — and sometimes transverse to 

 the beds, and nearly parallel to the dip-joints. Farther up the gorge are some con- 

 tortions ; after which the dip is reversed to the S.E. There are some good slate 

 quarries where this dip prevails, though the planes of slaty cleavage incline at a great 

 angle to the N.W. In nearly the whole gorge, up to the castle of Schwartzburg, 

 the induration of the rocks, the well-defined slaty cleavages transverse to the true 

 beds, the alternations of quartzites with the roofing slates, and the chloritic tinge 

 of many of the larger masses, reminded us of the lower roofing slates of West- 

 morland and Cumberland (Cambrian). 



About three or four miles up the valley, at Dachnitz, we found beds of half breccia- 

 ted and half concretionary marble dipping S.E. These beds alternate with bands of 

 slate, exhibiting a transverse cleavage, which does not affect the limestone ; and the 

 whole system is underlaid by black pyritous shales, containing many ferruginous 

 concretions. 



From Dachnitz we made a traverse on foot through mountain forests to Saalfeld. 

 In one of the gorges (near the last-named place), through which passes the great 

 road to Coburg, we found a limestone similar to that of Dachnitz, and associated in 

 hke manner with highly pyritous black shales used in the manufactory of alum. 



Again, about two miles above Saalfeld, we examined, a fine cliff on the right 

 bank of the river, composed of a reddish flagstone, some parts of which were 

 studded with minute calcareous concretions. The calcareous matter was not suffi- 

 ciently abundant to form any beds of limestone ; but the general mode of aggre- 

 gation was analogous to that in the limestone quarries above mentioned. These 



