BRITISH ASSOCIATION MEETING AT NEWCASTLE. 



385 



at which the waters of Tyne and Wear now run over its surface. 3. As 

 prior to this silting process the waters which caused the denudation must 

 have been in motion at a point at a depth of 140 feet below the present 

 level of the ocean, is it unreasonable to suppose that the whole length of 

 the valley in which it occurs was once at a higher level than that at which 

 it now exists ? 4. When the deep areas thus depressed and excavated 

 were sufficiently silted up, the now of waters, the produce of drainage 

 and springs in higher grounds, would flow off at the easiest level to the 

 sea by the present course of the rivers Tyne and Wear, the diversion in 

 favour of the latter being possibly induced by the subsidence of so large 

 a thickness of coal strata as occurs at Monkwearmouth, being here not 

 less than 2500 feet in depth, and composed extensively of argillaceous 

 shales, which are known to contract considerably in drying after being in 

 a moist condition. 



Permtan Rocks of the North-west of England. By Sir Roderick 

 Murchison. — The author described the Permian rocks as the newest pa- 

 laeozoic deposits forming a natural group, characterized by community of 

 animal and vegetable forms in various parts of Europe ; and until he pro- 

 posed the term Permian, this group had no collective name. In the east 

 of England there was no perceptible deposit that could be classed with 

 the Permian. In the north-west, particularly at St. Bees' Head and in 

 the valleys leading from the river Eden to the Pennine range, there was a 

 remarkable display of rocks, sandstones, and conglomerates, which were 

 linked indissolubly and conformably with the magnesian limestones. The 

 lower portion of the deposit, over a very large portion of England, was 

 formerly called the Lower Red Sandstone. All these deposits had been, 

 in the first instance, admirably described by Professor Sedgwick, whose 

 description had been the foundation of all our knowledge on this subject. 

 His reason for proposing this simple name was that he found on the Con- 

 tinent the representatives of the formation spread over a country twice 

 as large as France ; and when the same, community of character was found 

 in this country, our geologists adopted the name. He had asserted that 

 in Germany there was a great overlying sandstone superposed on the 

 magnesian limestone which formed the upper part of the group, and he 

 showed, in all sections that were typical, that this mass of sandstone went 

 with the magnesian limestone, and was completely separated from the 

 Triassic deposits which were named the New Red Sandstones. This con- 

 clusion was steadily contested by many German authorities, who did not 

 like to part with any portion of their Bunter Sandstein or to accord any 

 part of it to his Permian group. Amongst those who opposed this view- 

 was Dr. Geinitz, who had endeavoured to show that it was a dual deposit 

 and not a triad deposit, and he now called it Dias. Against that he (Sir 

 Roderick) had entered his protest. The labours of Mr. Binney, followed 

 by those of Professor Harkness, had, confirmed by his own survey of the 

 rocks, proved that in reality the west side of England offered the most 

 complete confirmation that could be given of the tripartite arrangement 

 of the Permian group, and completely fortified him in the opinion that 

 the Germans were wrong and that he was right. A detailed exami- 

 nation of the rocks, which he had been looking at with Professor Hark- 

 ness, had led him to the conviction that if you ascend any one of the 

 little groups, particularly the Hilton group, from the vale of Eden, up to 

 the great Pennine fault, you will find a succession of conglomerate beds 

 overlying the enormous mass of the lower portion of this great group. 

 The details had been explained by Professor Harkness, whose observa- 

 tions he confirmed. He called attention to the value of them in reference 



VOL. VI. 3 D 



