574 Meeting of the British Association. [Ofet., 



maintained that the two kinds of granite, the coarse and the fine r 

 in that island, had been erupted at different periods, and that the 

 difference in their texture arose from the difference in their ages. 

 This view, however, was opposed by Mr. E. A. Wiinsch, who had 

 accompanied Dr. Bryce during his explorations, and preferred to 

 explain the differences in question by the differences in the texture 

 of the original strata previous to metamorphism, a view which 

 appeared to meet with general support. 



While on the subject of Physical Geology we may refer to two 

 papers, by Mr. E. Hull, F.K.B., relating to the North- West of 

 England. In the first of these the author showed that the Car- 

 boniferous "sedimentary" rocks originally attained in the neigh- 

 bourhood of Burnley, along the Pendle Range, a thickness greater 

 than in any other part of Britain, and produced sections of the 

 strata, in this and other districts, in confirmation of his views on the 

 south-easterly attenuation of the Carboniferous " sedimentary " strata 

 of the north of England. Taking four sections along a south- 

 easterly line from Pendle Hill, the following were stated to be the 

 comparative thicknesses : — 



! North | South ! North | IjlSs!BtmMttt 



Lancashire. , Lancashire. ! Staffordshire. ^eicesterMiire. 



Coal-measures . . . ; 8,260 7,630 6,000 2,500 



Millstone Grit Series . ' 5,500 2,500 1,000 50 



Yoredale Series . . . ! 5,020 2,000 2.000 50 



18,780 12,130 



9,000 2,600 



The calcareous members are excluded from these sections, as having 

 been deposited on a different plan. 



In his second paper, Mr. Hull endeavoured to show that there 

 were three consecutive periods of disturbance of great force affecting 

 the Carboniferous districts of Lancashire. The first and the earliest 

 took place before the Permian period, and produced the upheaval 

 of the Lower Carboniferous rocks along the northern boundary of 

 the Lancashire and Yorkshire coal-fields. The second resulted in 

 the separation of the Lancashire and Cheshire from the Yorkshire 

 and Derbyshire coal-fields, by the' upheaval of the Lower Carboni- 

 ferous rocks along " the Backbone of England ; " and might be 

 referred to the close of the Permian, or Paleozoic period. The 

 third had produced the system of north-north-westerly faults which 

 traversed the coal-fields, as well as the Permian and Triassic form- 

 ations of Cheshire. This system of disturbances the author con- 

 sidered to be referable to the close of the Jurassic period. The 



