Published online by Cambridge University Press: 01 May 2009
When a group of beds has well-defined boundaries above and below, and when moreover its palæontological characteristics coincide with its stratigraphical limits, it becomes a boon alike to the field-geologist and to the fossil collector. When, on the other hand, both limits and fossils fail to enable one to follow a group beyond a certain point, the sooner the series as such is relegated to the limbo of purely-local, convenient, but untrue divisions, the better. I propose to show in this paper that the important group of beds commonly known as the Yoredale Series in the North-Western parts of Yorkshire is a group of the latter kind, convenient indeed in that district, but quite incapable of being traced much further North either stratigraphically or palæontologically.
page 539 note 1 Essay on the Geology of Cumberland and Westmorland, by Nicholson, H. A., D.Sc, F.G.S., etc., London and Manchester, 1868, p. 79.Google Scholar
page 540 note 1 On the Whin Sill of Northumberland, by W. Topley, F.G.S., and G. A. Lebour, F.G.S. (Abstract in Report of the British Association for 1873, London, 1874, part 2, p. 92).Google Scholar
page 540 note 2 On the ‘Great’ and ‘Four-Fathom’ Limestones and their associated beds in South Northumberland, by Lebour, G. A., F.G.S., etc., Trans. N. Engl. Inst. of Min. Eng., 1875, vol. xxiv. p. 140, and fig. i. pl. xxxiii.Google Scholar
page 540 note 3 Mr. R. Howse, in discussion on above paper, ibid. p. 147.
page 541 note 1 Nicholson, op. jam. cit., p. 78.
page 541 note 2 The geological map which accompanies the Coal Commission Report is an exception, although in that map the assumed doubtful line of boundary between Yoredale and Scar is more out than usual, owing, doubtless, to the general character of the map.
page 541 note 3 A Synopsis of the Geology of Durham and Part of Northumberland, by Richard, Howse and Kirkby, J. W., Newcastle-on-Tyne, 1863, p. 22.Google Scholar
page 542 note 1 The Scar beds are not supposed to be worth much for lead-mining purposes, and are therefore, with a few striking exceptions, seldom worked into.
page 542 note 2 On the “Little Limestone” and its Accompanying Coal in South Northumberland, by Lebour, G. A., Trans. N. Engl. Inst. Min. Eng. 1875, vol. xxiv. p. 1, et seq.Google Scholar
page 543 note 1 Up to the present time, the well-marked foraninifer Saccammina Carteri, Brady, is apparently limited to a bed in the Upper or Yoredale part of the series, viz. the Four-fathom Limestone.
page 543 note 2 Abstract of Proc. of the Geol. Soc. of London, No. 296, p. 2.
page 543 note 3 Physical Geology and Geography of Great Britain, by Ramsay, A. C., LL.D., F.R.S., 2nd edition, 1872, p. 76.Google Scholar