Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/44

22 the conglomerate immediately underlies the great mass of sandstones of group 4, and that it is underlain in its turn by the sandstones and breccias of group 2, I incline to the opinion of the older geologist, and place it, with him and Prof. Sedgwick, in the middle group of Permian strata.

Section 13 is regarded by Mr. Hull as a typical section. With that of Alberbury, it has, in group 2, sandstones and marls, in group 3 a somewhat similar conglomerate, with a base of trappoid breccia, which perhaps belongs more properly to the top of group 2; these are overlain by the usual mass of red and purple sandstones.

The district lying between this point and the Bristol Channel has been well described by Prof. Ramsay, who places the Abberley conglomerates on the same horizon as that of Alberbury. There is a remarkable resemblance in the mineral composition of the breccias described by him and those of group 2 in the Ifton section, composed, as both are, of felstone, porphyry, greenstone porphyry, amygdaloid slate rocks, altered sandstones, and quartz.

It was from the occurrence of large scratched boulders in this conglomerate that Prof. Ramsay inferred the prevalence of glacial conditions in the climate of that period.

Section 14 is from the pit-sinking of Coppice-Hall colliery, near Walsall: I had hoped to be able to give the section of the new sinking at Sandwell Park instead; but all the attempts I have made to obtain any information of it or of the promised book descriptive of it have been ineffectual. Both the Walsall and Tunstall sections are situated, though far apart, on the eastern side of the New-Red-Sandstone plain of Shropshire and part of Staffordshire; and they are interesting from the similarity of the strata in group 2 to those of the Ifton section in the same division, pointing (as this similarity does) to a continuity underground through the intervening area.

Section 15 is one described by Mr. Howell of the strata overlying the Warwickshire coal-field. In group 1, Mr. Howell states that the Spirorbis-limestone occupies a position about 50 feet below