240 Professor Sedgwick and Mr. Murchison on the 



where these ores occur (as is often the case) with courses of limestone, the mass 

 is frequently charged with fossils. In this ferruginous matrix the characteristic 

 forms of Shigocephalus, Goniatites, and Calceola sandalina, are found near Brilon 

 and Meschede. They are also found at Martenberg, five miles south of Stadt- 

 berg (the extreme point of these ancient rocks), where the older strata are over- 

 lapped horizontally by Kiipfer schiefer, greensand, &c. (see map, PI. XXIV.). Dis- 

 turbed, therefore, as the tract has been, still each zone may be clearly distinguished 

 — the outer (or lower carboniferous) by its small plants, its carbonaceous character, 

 and its courses of " kiesel schiefer," black limestone, and shale with Posidonice — 

 the inner (or Devonian zone) by its limestones, fossils, iron ores and slates : and 

 both may in like manner be distinguished from the older grauwacke (or Silurian 

 rocks), of which we shall treat hereafter. 



Besides a complete reversal of the formations (and upon such an enormous 

 scale) , this tract exhibits a very singular insulated mass of the Devonian limestone 

 in a highly mineralized condition at Warstein, about ten miles north of Meschede. 

 Surrounded by hills of slaty schist, psammite and kiesel schiefer, this limestone 

 breaks out to the surface. Its structure is very much varied, and it contains 

 amorphous masses of dolomitic and of a veined, impure limestone, associated 

 with hornstone and iron ore. The ore is worked in pits, some of which are up- 

 wards of forty fathoms in depth, and seems to occur in masses more or less ver- 

 tical. Both in its structure and its position among the surrounding rocks, it 

 resembles the kidney ore deposited in fissures of the mountain limestone near 

 Ulverstone. That plutonic rocks, though not apparent at the surface at War- 

 stein, have had their influence in producing some of these results, is a fair infer- 

 ence from analogy. 



Some of the porphyries of these tracts, especially those of the ridges to the 

 south of Brilon, Bilstein, and Kleine-Poppelsberg, have a character intermediate 

 between intrusive porphyry in mass, and those varieties of finely laminated and 

 bedded porphyritic rocks which (although they contain both concretions and 

 crystals of felspar) are often interstratified with courses of schist and limestone, 

 and dip along with them to the S.S.E. In the sequel we shall have to speak 

 at greater length of the extraordinary variety of forms put on by the bedded trap- 

 pean rocks, when they pass into the state of " schaalstein." All the sedimentary 

 deposits in contact with the porphyries and greenstones of Brilon and Meschede 

 are much altered ; the calcareous bands being either blended with hornstones 

 or impregnated with iron ores, while the schists and slates are often traversed 

 by veins of lead and copper ore. The longitudinal valley of Hoppeke, south 

 of Brilon, offers an excellent illustration of the manner in which the bands and 



