Western part of the Palatinate. 227 



Mont Tonnerre, I observed among the tiappean rocks a 

 remakable mixture of talcose parts, and silky asbestos. 

 Breccias and conglomerates are also observed in this forma- 

 tion, composed of fragments of cornean and quartz, sometimes 

 very large,* at others so fine that the rock insensibly passes 

 into a red sandstone (rothe liegende). These arenaceous 

 rocks commonly appear above the crystalline rocks, often 

 also the superposition of the red sandstone on the trap is 

 very distinct, as is seen near Winnweiler ; but sometimes 

 also the whole appears disposed in alternating beds, and in 

 this case an insensible passage may often be observed from 

 the cornean or wacke to a fine grained sandstone : I have 

 observed the latter fact at the Schaumberg, near Tholey, on 

 the N. of St. Wendel, in the hills which border the Brems 

 near Wadern, on the banks of the Nahe near Durckroth, and 

 elsewhere. Sometimes the paste of the cornean, by alter- 

 ation, becomes whitish, soft, and unctuous ; it is theni 

 worked as fuller's earth. 



From the environs of Birkenfeld to below Oberstein, the! 

 principal trap band is many leagues broad on the right bank 

 of the Nahe, where it extends to beyond Baumholder. 

 Throughout all this country, the coal measures lest on the 

 slope of the trap mountains. Further to the N.E. the latter 

 are more contracted ; in the environs of Kyrn, the coal 

 measures traverse the Nahe in many places, and the trap 

 rocks occur above them, and it is then that they especially 

 become analogous to the basalts. I have observed the su- 

 perposition of these rocks on the coal measures, principally 

 on the banks of the Nahe, near the coal mine of Durckroch, 

 and near Hefersweiler, 2 leagues to the E. of Wolfstein. 

 An analogous fact it is imagined may be observed in the 

 mountains of Landsberg and Stahlberg, celebrated for their 

 mines of mercury ; but the whole interior of these mountains 

 appears so much disturbed, that it is very difficult to deter- 

 mine any real superposition. On the contrary, 1 have seen 



* A singular breccia formed of fragments of cornean cemented by a 

 cornean paste or base, occurs associated witli trap at Cutfern mountain 

 near Roch, and in Ramsay Island, Pembrokeshire. (Trans.) 



p2 



