314 Rev. A. Irving — Geology of the Nottingham District. 



tlie displaced water ; and the rise in the latitude of Edinburgh, would 

 be 312 feet. The fall of level on the southern hemisphere would, 

 of course, be equal to the rise of level on the northern. According 

 to the method advanced by Mr. D. D. Heath (Phil. Mag. for April, 

 1866, p. 323), the rise of level at the North Pole would be about 

 650 feet. Archdeacon Pratt's method (Phil. Mag. for March, 1866, 

 p. 172) makes the rise still greater; while according to Rev. 0. 

 Fisher's method ("Reader," 10th FcId. 1866) the rise would be no 

 less than 2000 feet. There is, however, another circumstance which 

 must be taken into account, which will give an additional rise of 

 upwards of one hundred feet. 



(Fo be continued.) 



IV. — On the Geology op the Nottingham Distkict.^ 



By the Eev. A. Irting, B.A., B.Sc, F.G.S., 

 Second Master of the Hig-h School, Nottingham. 



GLANCE at the map shows that within a short distance of the 

 town of Nottingham there are Coal-measures, Permian, Bunter, 

 Keuper, and Lias rocks. A paper therefore on the district must 

 of necessity be somewhat lengthy, but perhaps of all the greater 

 interest as dealing with the border-land of the Palaeozoic and Mesozoic 

 epochs. The generally supposed unconformability between the Per- 

 mian and Triassic rocks does not appear to exist in this area ; while 

 that between the Permian and the Coal-measnres is very consider- 

 able. 



(1). Coal-measures. — There are seven seams of coal at present 

 worth working in this coal-field, with many more of inferior quality. 

 The uppermost of the seven is the "Top-hard" or "Barnsley" Coal, 

 the lowest the Kilburn Coal. Below the latter are the compara- 

 tively worthless strata known as the "Ganister Beds," which are 

 found on the Derbyshire side of the coal-field, resting upon the 

 Millstone-grit. The enormous unconformability betv/een the Coal- 

 measures and the Permian is shown by the fact that at the Shire- 

 oak Colliery, near Worksop, 1300 feet of Coal-measures had to be 

 penetrated in sinking the shaft before the Top-hard seam was 

 reached ; while at Strelley, rather more than twenty miles to the 

 south, the Magnesian Limestone is seen, as the author is informed 

 by Mr. G. Fowler, C.E., resting immediately upon the same seam. 

 This so far corroborates the opinion of Mr. Howell, that the 

 axis of the elongated basin in which these Coal-measures probably 

 lie is along a line passing north-west and south-east through 

 Bradford and Worksop. At the same time it removes the Permian 

 rocks, by an enormous space in time, from the Carboniferous Period. 

 This removal is further shown by the examination of a fault at the 

 Cinder Hill Colliery, at Basford. This fault has been found, by 

 actual measurement in the pit, to have effected a displacement in 

 the Coal-measures to the extent of 88 yards of throw, while the 

 same fault, passing upwards through the Permian and Bunter rocks, 



^ Being the substance of a paper read before the Geologists' Association, March 6th . 

 — Prof. Morris, F.G.S., Vice-President, in the Chair. 



