294 Professor Sedgwick and Mr. Murchison on the 



some beds may have been brought up, by the action of the granite, of an older 

 date than any of those above described in the traverse from Elbingerode. 



From the lower gorges of the Bode we returned to the south-eastern edge of 

 the great calcareous dome near Hiittenrode. The ascending section is there more 

 clear than on the banks of the Bode, being less modified and interrupted by the 

 trappean slates. It is nearly as follows : — 



(1.) Great limestone. 



(2.) Four or five bands of limestone, alternating with masses of brown and some red iron ores. 

 (3.) Stratified slaty trappean rocks (schaalstein, &c.), alternating with some dark slates, 

 (4.) Dark-coloured slates, &c. 



Beyond Hiittenrode the bands of ironstone recede towards the north, bending 

 round with the dome of limestone ; and along the new chausse'e, from Hiittenrode 

 to Blankenburg, both black slate and kiesel schiefer are seen distinctly to overlie 

 the limestone series. The analogy with the Westphalian sections {supra, p. 229 

 etseq.) is therefore still more complete than we had shown it to be in either of the 

 two preceding traverses. 



Lastly, we descended to Blankenburg among schists, psammites, and masses of 

 eruptive trap, probably of an older date than any of the rocks in the above 

 section. 



Two lines drawn, in the strike of the beds, across the chain, one through the 

 granite of the Brocken, the other through the granite of the Rosstrappe, will cut off 

 a great central area. Within this area, are the rocks last described, and on the north- 

 eastern side of it we have shown that the Devonian system is widely expanded. The 

 beds on the south-western side of the central area we did not examine ; but, from 

 general analogy, and from the information we obtained respecting them, we believe 

 that none of them are older than the Silurian grauwacke of the Rhenish provinces. 



South-eastern Extremity of the Hartz. 



A line drawn along the strike of the beds a little north of Ballenstadt and Stoll- 

 berg, cuts off the south-eastern extremity of the Hartz, which it remains for us 

 very briefly to notice. 



We made one excursion from Ballenstadt to Magdesprung, and thence down 

 the whole gorge of the Selke. We found a dark limestone, with white veins, 

 alternating with schists and psammites near the Furst-weg, about three miles from 

 Ballenstadt ; but we were not fortunate enough to find any fossils associated with 

 it. After descending among bosses of trap to Magdesprung, we found beds of hard 

 glossy clay slate, with a true transverse cleavage, crossing the Selke below the 

 village, and dipping about S.E. Further down the banks of the river the slates 



