BEITISH ASSOCIATION MEI:TI^'a AT NEWCASTLE. 
385 
at wkLcli the waters of Tjne and Wear now run orer its surface. 3. As 
rior to this siltinoj process the waters which caused the denudation must 
are 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 flow of waters, the prodtice 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 drj-ing after being in 
a moist condition. 
Peemtan Rocks of the Nobth-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 Eed Sandstone. All these deposits had been, 
in the first instance, admirably described hj Professor Sedgwick, whose 
description had been the foundation of all otir 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. TI. 3 D 
