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



1 . Among the lower beds visible towards the west is an amyg- 

 daloid (fig. 9, a) composed of two varieties of quartzless porphyry, 

 one of which contains small nests of zeolite in a base of felspar-wacke. 

 The other is a sort of " bladder-stein" with green earth, and both 

 are interlaminated with the red sandstone, and are manifestly con- 

 temporaneous with the other strata. 



2. A thick mass of deep red, earthy, thin-layered sandstone (&), 

 containing many grains of whitish felspar. Though not exhibited in the 

 hill of Leimbach, this part of the formation (south of Mansfeld) affords 

 extensive quarries of finely laminated, but thick-bedded building- 

 stone; the beds being separated at intervals by earthy greenish layers. 



3. A whitish-coloured conglomerate (c), studded with many pebbles 

 of white quartz, doubtless derived, as before stated, from the old 

 quartz rocks of the Wippra Thai (see p. 431). This band forms a 

 striking feature on the hill side. 



4. Dark red argillaceous sandstone {d\ with thin concretionary 

 courses of brown and grey calcareous grit. 



5. The underlying strata just described are at once conformably 

 overlaid by about 30 feet of Zechstein {e), the base of which, how- 

 ever, is ill-exhibited. It appears that the German miners, who 

 have so accurate an acquaintance with their Kupfer-schiefer, have 

 not been able to detect it here, in its usual place between the lower 

 rock and the Zechstein. The course sets in, however, in that posi- 

 tion a little to the east of Mansfeld. This layer, originally deposited 

 in the state of cupriferous mud, must here have thinned out on an 

 ancient pebbly shore, the bed of which now forms the escarpment 

 described. In other and adjacent tracts of Central Germany, its 

 extraordinary persistence over wide areas has already been explained. 



The magnificent ruins of the once powerful castle of Mansfeld 

 stand on the upper and pebbly beds of the Rothe-todte-liegende ; 

 but great dislocations have affected the flanks of this mass, and no 

 good section like that of Leimbach is there to be seen. 



Before we quit the consideration of the Rothe-todte-liegende of the 

 region around the Harz, we beg to state, that, although, as before said, 

 there are very rare occurrences of poor and thin coal in that rock, all 

 the best local authorities, including M. Plumecke of Eisleben, are 

 agreed, that the old coal* properly so called (the Stein-kohlen-gebirge 

 of the Germans) lies entirely beneath the Red rock. Having also in- 

 terrogated M. Breslau, a practical '* bergmeister " who has observed 

 the progress of a great trial for coal now going on near Rotheburg, we 

 ascertained that slightly inclined red sandstone and conglomerate, in 

 which one thin course of limestone without fossils has been noted, have 

 there been pierced to a depth of 1000 feet without a trace of coal. 

 Though the speculators hope to find it beneath the great Red cover, 

 we have already adverted to much deeper sinkings in the same rock, 

 near Eisenach, which have entirely failed. 



Zechstein^ with Kupfer-schiefer and other associated strata. — 

 In numerous places around the older rocks of the Harz, the Zechstein 



* At Wettin, Ilmenau, &c. 



