of two Rocks of Basalt near Niirburg in the Eifel. 177 



sing adit has been driven close. It consists of various frag- 

 ments of rocks, and its course is parallel with the magnetic 

 meridian, and consequently with the group of basalt of Niir- 

 burg. The mountain consists of grauwacke-slate, formed of 

 beds of common grauwacke, slaty grauwacke, and clay-slate. 

 By the trials since made, under the name of Katliarinengrube, 

 it is found to fall 70° S. ; a clip which is as little constant as 

 its direction. The great character of the strata is undulation, 

 and the greater declivities run S. and S.E. 



" The line on which the three highest cones, the Hohe- 

 Acht, the Niirburg and the Hoch-Kellberg, are placed, is the 

 south-eastern range of the Eifel, from the southern declivities 

 of which the waters stream towards the Mosel and Rhine, but 

 from the north-western declivity, towards the Ahr. 



" It seems as if the basaltic cone of Niirburg had afforded 

 some protection to the grauwacke-slate, as the latter gently 

 rises even to the spot whence the former abruptly ascends. 

 The mass of basalt is indeed small when we consider the view 

 it affords from a distance; but on the other hand the highest 

 cone is surrounded by several smaller ones, some of which, 

 such as the Selberg, at its northern foot, near Guiddebach, 

 equal it in bulk. This Selberg rises from the bottom of the 

 valley without, its top reaching the elevation of the borders of 

 the valley. Other cones of a gray colour lie on the southern 

 declivity of the same valley to the N.E. of the Niirburg; 

 towards the E., at a distance of about 150 fathoms, rises on the 

 table-land of the mountain chain a low gentle acclivity, with 

 low rocks, called the Stein- Ecke, and a quarter of a German 

 mile, towards the S.W., rises a remarkable cone. From this 

 cone several very small masses of basalt run in a line towards 

 the Niirburg, as it were marking the throwings up of an adit. 

 Except the Stein-Ecke, all these masses of basalt have nothing 

 to distinguish them from others of a similar formation. Look- 

 ing from the top of the Niirburg, I perceived at first some- 

 thing on the eastern flat hill resembling some unimportant 

 ruins of a building. Instead of ruins, however, I found two 

 insignificant rocks, about half a fathom distant from each other 

 in their diagonals, about one fathom high, and holding each 

 half a square fathom in their base. The south-eastern rock is 

 one fathom long, half a fathom broad ; the other to the N. W. 

 a little shorter, but broader. Both rocks are in strata, or ra- 

 ther are separated into thick slabs, as is seen in flinty-slate, 

 which slaty structure is parallel to the long sides. Their dip is 

 twelve hours, and therefore parallel to the basaltic range on 

 which they lie, as well as to that of the metallic ore mentioned 

 above. The separating surfaces fall 73° E. This inclination 



N. S. Vol. 8. No. 45. Sept. 1830. 2 A does 



