Published online by Cambridge University Press: 01 May 2009
The north-country lamprophyres occur usually as dykes of no great magnitude, sometimes as sills, more rarely as small bosses or laccolites. They are scattered over an area extending from Teesdale to Furness, from Bassenthwaite to Ingleton. A circle thus defined has a diameter of about fifty miles, and embraces all the known occurrences, though others may exist beyond these limits concealed by post-Silurian strata. In the centre of the circle is the Shap granite, and the probable genetic connexion between the lamprophyres and this granitic intrusion has already been urged by Mr. Marr and the present writer.
page 199 note 1 It may be remarked here that the lamprophyre of Sale Fell, near Bassenthwaite, which is of a somewhat acid variety, may possibly have had a quite distinct origin.
page 199 note 2 Bonney, (analyses by Houghton), Q.J.G.S., vol. xxxv. p. 160;Google Scholar Eutley,ibid.vol. xxxiv. p. 29, and Mem. Geol. Suvv. Ingleborough (97 S.W.); Tate, Proc. Torks. Geol. Pol. Soc. vol. ix. p. 372, vol. xi. p. 311, and Rep. Brit. Assoc. for 1890, p. 814; Hatch,ibid.p. 813, and Mem. Geol. Surv. Mallerstang (97 N. W.); Balderston, , “Naturalist,” 1889, p. 131;Google ScholarHarker, and Marr, , Q.J.G.S., vol. xlvii. p. 285;Google Scholar Harker, ibid. p. 521; see also Teall, “Brit. Petr.” chap. x.
page 200 note 1 Iddings, , Amer. Journ. Science, vol. xxxvii. p. 208 (1888).CrossRefGoogle Scholar
page 201 note 1 Tsch, . Min. Mitth..(2) xi. p. 27 (1890).Google Scholar
page 202 note 1 The name mica-trap evidently cannot be made to cover all the types here included.
page 202 note 2 Tsch, . Min. Mitth. (2) vol. xi. p. 445.Google Scholar
page 202 note 3 Rep. Geol. Surv. Ark. for 1890, vol. i.Google Scholar
page 203 note 1 Mitth, . Grossherz. Baden Landes, vol. ii. p. 258.Google Scholar
page 203 note 2 Brögger, , Syenitpegmatitgänge, p. 49.Google Scholar
page 204 note 1 Zeits, . deuts. geol. Ges. vol. xli. p. 163 (1889).Google Scholar