290 . Professor Sedgwick and Mr. Murchison on the 



the kiesel schiefer. The structure of the rock was very interesting. The component beds were greatly- 

 contorted, and intersected by a fine, highly inclined, transverse, slaty cleavage inclining to the S.E. A 

 number of regular horizontal joints gave a false appearance of horizontal bedding, and these were inter- 

 sected by another system of dip-joints, with seams of carbonate of lime. The lower part of the valley 

 (where the river emerges into the plains of keuper, muschelkalk, &c.,) gave us no additional information. 



Section (N.N.W. and S.S.E.) from the Hills a few miles north of Goslar, through 

 Rammelsherg to the Granite of Ocker Thai. 



The woodcut, Fig. 14, given in p. 286 will be sufficient to convey a general notion of the actual posi- 

 tion of the mineral masses in this section. 



1. We have first a series of dark earthy slates and psammites much contorted. 



2. Then a series of hard dark glossy roofing slates, interrupted by great alternating parallel ridges of 

 trap (e.ff. in Grana Thai, Nordberg, and Steinberg). These schists have a fine slaty cleavage, which 

 hangs steadily to the S.E. at a great angle. Some of the slates, alternating with the thick bands of trap, 

 are, however, highly contorted, and of very complicated mineral structure, as is shown in the accom- 

 panying woodcut. 



Fig. 16. 



Slate-quarries of Nordberg, near Goslar. 



The undulating lines of this figure indicate the bedding ; the inclined lines the cleavage ; and the horizontal hnes the 



pecuUar joints or floors. 



Trap. 



The true beds of slate are marked by a contorted stripe. The sides near the trap are altered and in- 

 durated ; the slaty cleavage is very well defined, dipping at a high angle to the S.E. ; and the whole 

 mass is separated into well-marked tabular masses by horizontal joints. 



3. The preceding series is overlaid by soft earthy slates (of the gorge above Goslar), which, in their 

 turn, are overlaid by the series of the Rammelsberg. The beds here continue on the whole to hang to 

 S.E., but not at a great angle ; and there are several small undulations, by which the dips are changed 

 and sometimes reversed. Many of the beds are, however, intersected by planes of cleavage, inclined at a 

 great angle toward the south-east, which sometimes convey a false notion both of the bedding and dip. 

 Near the top of the hill we have the following apparently ascending section : — 



(1.) Hard grey well-bedded sandstone. 



(2.) Hard flagstone, with bands of indurated slate. 



(3.) Chert or quartz rock, broken into small irregular fragments by joints coated with ferruginous 



stains. 

 (4.) Ragged arenaceous slates. 

 (5.) Hard quartzose arenaceous beds rising to the top of the hill. The preceding beds contain a few 



fossils. 



Following the line of section to the southern side of the mountain, we found the arenaceous system 



