and afterwards by Mr. Binney[1]. It is an interesting section, combining, as it does, the features of the strata on both the western and eastern sides of the North of England. Prof. Sedgwick says the Magnesian Limestone of group 3, is the exact equivalent of the Magnesian Limestone of Nottingham, Yorkshire, and Durham. The same is true, he states, of the red marls and gypsums, while the red sandstone of St. Bees Head, group 4, is unquestionably the exact equivalent of the Upper Red Sandstone of those counties. The lower part of the section, group 2, is more fully described by Sir R. I. Murchison and Prof. Harkness in the paper already referred to.
Section 5 takes us over to the eastern coast of England. It is taken from the pit-section of the Monkwearmouth Colliery. It will be observed that the same order prevails in group 3 as on the western coast, except that here the limestone has thickened considerably. Group 2 is represented by about 45 feet of red and grey sandstones. Group 4 is not represented at all. This district is more fully described in section 17.
Section 6 brings us southward down the eastern side of England, to the country around Leeds. It is given by Messrs Aveline, Green, Ward, Dakyns and Russell[2]. The upper limestone is described as grey, hard, and full of fossils. It contains little or no magnesia.
The lower limestone is yellow in colour; it decomposes readily near the surface. It sometimes contains a hard flinty rock locally known as "calliard;" and, in places, its lowest beds are pebbly. Its common fossils are Schizodus of three species. The interstratified and overlying marls are red and variegated. They alternate with beds of soft sandstone, which, in places, contain deposits of gypsum. The authors describe these beds as slightly unconformable to each other; but they hardly mean to imply, I should think, that they represent the three great divisions of the Permian strata.
A more complete view of the Permian strata of South Yorkshire is the following, given by Mr. J. W. Kirkby[3].
Group 3 of Sections.
ft.
- Brotherton Limestone and lower red marl and gypsum of Brotherton, Knottingley,Womersley,Wadworth, Tickhill, &c.
120
- Small-grained dolomite of the Vale of Went, Lound Hill, Cusworth, Levit, Hagg, Roche Abbey. Warmsworth, &c.
200
- Lower Limestone of Pontefract, Wentbridge, Conisborough, &c.
120
Group 2 of Sections.
ft.
- Lower red, yellow, and variegated sandstone of Pontefract, Hickleton, Cadeby, &c.
100
This section brings us nearer, geographically, to Section 7, which shows the strata overlying the Nottinghamshire coal-field. Group 2 is taken from the pit-section of the Shire-Oaks Colliery; the red and grey sandstones at its base are taken by local engineers to be
