398 Prof. Sedgwick on the New Red Sandstone Series in the 



neighbourhood of Whitehaven : for in following- the overlying deposits into 

 the interior of the coal fields we find many traces of magnesian" conglomerates, 

 with rolled masses of mountain limestone, in every respect identical with those 

 of the coast section (for example, at Gilgaron, near Arlecdon, at Sand 

 Closes, &c.) ; and we have the clearest proof that the lower red sandstone 

 had been exposed to considerable degradations, and scooped out into great 

 hollows before the conglomerates, which form the base of the magnesian lime- 

 stone^ were first accumulated. It follows, therefore, that the "lower red sand- 

 stone" overlying the Yorkshire and Durham coal fields, and the lower red 

 sandstone of Cumberland, are identical in their structure, their relations, their 

 fossils, and in all the accidents to which they were exposed during their de- 

 position. We may therefore conclude that they are true geological equiva- 

 lents ; that they are probably on the parallel of, at least, the lower portion of 

 thegr^s des Vosges ; and that they are unquestionably the equivalents of the 

 rothe iodte liegende overlying the coal series at the southern extremity of the 

 Hartz mountain. 



The magnesian conglomerates^ described in the previous details of this 

 paper, cannot be classed with the lower red sandstone, to which they are 

 sometimes unconformable ; but they graduate into^ and form an integral part 

 of, the magnesian limestone, sometimes appearing entirely to replace it. 



The magnesian limestone of the coast section is evidently on the exact 

 parallel of the magnesian limestone of Nottinghamshire, Yorkshire, and Dur- 

 ham, though not developed on so large a scale, or separable into the same 

 number of minute subdivisions. It is not coextensive with the upper division 

 of the overlying sandstone series; but it mai/ exist in many places, under the 

 great heaps of transported matter ; and it breaks out, as above stated, in a 

 very characteristic form, from beneath the new red sandstone of Low Furness, 

 in a deep valley near the village of Stank*. With this exception, I have never 

 seen it beyond the promontory of St. Bees Head, in any place within the 

 limits of the range of country above described. 



The red marl and gypsum under St. Bees Head are very nearly on the 

 parallel of the " /ower red marl and gypsum " of the Yorkshire series t ; and 

 the red sandstone of St. Bees Head is unquestionably the exact equivalent of 

 the upper red sandstone of that series. The "upper red marl and gypsum" 



* See Plate XXV. fig. 7. 



\ There are in Yorkshire two deposits of red gypseous marls under the great mass of the upper 

 new red sandstone ; one under, the other over the thin-bedded limestone of Ferrybridge. With 

 either of these the gypseous marls of St. Bees Head may be brought into comparison, as the 

 Ferrybridge limestone is not seen in Cumberland. 



