On the Permian Rocks of the North-west of England. 543 



In this paper the authors propounded a new view of the composi- 

 tion of the Permian Group in the north-west of England, and, by the 

 consequent rearrangement of the rocks involved in this change in 

 classification, they were enabled to place the Permian strata of Great 

 Britain in direct correlation with those of the continent of Europe. 

 This new feature in British classification is the assignment of a large 

 amount of red sandstone in the north-western counties to the 

 Permian period, and its removal from the New Red Sandstone, or 

 Trias -formation, to which they have hitherto been assigned in all 

 geological maps. The authors showed that these red sandstones are 

 closely and conformably united with the Magnesian Limestone or its 

 equivalent, and form the natural upper limit of the Palaeozoic de- 

 posits. They affirmed that thus a tripartite arrangement of the Per- 

 mian rocks holds good in Westmoreland, Cumberland, and Lanca- 

 shire, and that the three subdivisions are correlative with those for- 

 merly shown by Sir R. I. Murchison to exist in the Permian deposits 

 of Germany and Russia, thus proving the inapplicability of the 

 term Dyas to this group of rocks. 



The difference in lithological details of the Permian rocks of the 

 north-west of England from those on the opposite flank of the Pen- 

 nine chain was next adverted to ; and it was observed that, with so 

 vast a dissimilarity in their lithological development in England, we 

 need not be surprised at finding still greater diversities in these pro- 

 tean deposits when followed into Germany and Russia. 



The discovery, by Professor Harkness, in the central member of 

 this siliceous group in Westmoreland, of numerous fossil Plants 

 identical with the species of the Kupfer-Schiefer in Germany, and in 

 the Marl-slate of the Magnesian Limestone of Durham, was given as 

 a strong proof of the correctness of the authors' conclusions. 



The comparative scarcity of igneous rocks, and the evidence of 

 powerful chemical action, in the Permian strata of Britain, is con- 

 trasted with their abundance in deposits of that age in Germany ; 

 but proofs are nevertheless brought forward to show that the 

 hsematite of Cumberland and Lancashire was formed in the early 

 accumulation of the Permian deposits. 



In describing in detail the different members of the Permian 

 group of the north-west of England, the authors define the down- 

 ward and upward limit of the strata which have undergone dolo- 

 mitization ; for whilst certain bands of calcareous breccia (the 

 " brockrum " of the natives), which occur in the central portion of 

 the series, contain much magnesia, the lower breccias, composed of 

 the same mountain- limestone fragments, have no trace of it ; nor is 

 it to be detected in the upper member, or St. Bee's Sandstone. 



February 24. — W. J. Hamilton, Esq., President, in the Chair. 



The following communications were read : — 

 1. "On further Discoveries of Flint Implements and Fossil Mam- 

 malia." By J. Wyatt, Esq., F.G.S. 



The opening of a section at Summerhouse Hill gave the author 



