Augite from Bail Hill, Dumfriesshire
Published online by Cambridge University Press: 14 March 2018
Extract
The crystals to which this paper refers are found at Bail Hill, about three miles north of Sanquhar, in Dumfriesshire. At this locality volcanic rocks of Arenlg age outcrop in the midst of the greywacke of the Southern Uplands. The rocks are mainly lavas, and include some coarse-grained tufts which are composed chiefly of augite- and hornblendeandesites. Ill the andesitic fragments, there arc numerous porphyritic crystals of a black augite, which call be easily separated from the rest of the rock. Isolated crystals of augite and hornblende occur also in the matrix of the tufts. No mention of this occurrence is made in Heddle's 'Mineralogy of Scotland', and apparently the only reference to it in previous literature is the short petrographic description in the Geological Survey Memoir.
- Type
- Research Article
- Information
- Mineralogical magazine and journal of the Mineralogical Society , Volume 17 , Issue 79 , July 1914 , pp. 100 - 110
- Copyright
- Copyright © The Mineralogical Society of Great Britain and Ireland 1914
References
page 100 note 1 ‘Silurian Rocks of Scotland,’ Mem. Geol. Survey, 1899, pp. 87, 306Google Scholar.
page 100 note 1 i. e. the acute angle between a and the s-s edge.
page 100 note 2 Rosenbusch, H., Mikroskopische Physiographie, 1905, vol. i (2), p. 207, Pl. VI fig. 3Google Scholar.
page 100 note 3 Williams, G. H., Amer. Journ. Sci., 1887, ser. 3, vol. xxxiv, p. 275Google Scholar.
page 103 note 1 R. E. Liesegang, 'Ueber die Schiehtungen bei Diffusivnen,' Leipzig, 1907.
page 103 note 2 The most generally accepted explanation of Liesegang's phenomonon is that due to Ostwald (Zeits. Physik. Chem., 1897, vol. xxiii, p. 865), who attributes it to supersaturation.
page 104 note 1 L. van Wervoke, Neues Jahrb. Min., 1879, pp. 482, 882.
page 104 note 2 H. Rosenbusch, Mikroskopische Physiographie, 1905, vol. i (2), p. 210.
page 104 note 3 J. Blumrich (Min. Petr. Mitt., 1892, vol. xiii, p. 239) was the first to notice that this hour-glass structure is practically confined to augltes in alkali-rich rocks. A summary of the different occurrences is given by Pelikan (Min. Petr. Mitt., 1896, vol. xvi, pp. 1-64).
page 104 note 4 Gaubert, P., Bull. Soc. franç. Min., 1905, vol. xxviii, p. 286 Google Scholar.
page 104 note 5 Gaubert, P., Compt. Rend. Acad. Sci. Paris, 1910, vol. cli, p. 1134 Google Scholar.
page 105 note 1 P. Gaubert, 'Recherches récentes sur le Facies des Cristaux,' 1911, p. 26.
page 106 note 1 The differences between the values of B for the s-sector as calculated from the axial angle and as observed by the prism method are probably to be explained by the fact that section 3 contained b- and m-sectors in addition to a and s, and it is very difficult to distinguish those sectors from the s. The prism values of β are certainly the more reliable.
page 107 note 1 Less than 0·006 per cent.
page 107 note 2 G. Tschermak, Min. Mitt., 1871, p. 21.
page 108 note 1 Wiik, F. J., Zeits. Kryst. Min., 1884, vol. viii, pp. 208–210 Google Scholar.
page 108 note 2 Doelter, C., Neues Jahrb. Nin., 1885, vol. i, p. 56 Google Scholar.
page 108 note 3 Hintze, C., ‘Handbuch der Mineralogie,’ 1897, vol. ii, pp. 1025–1029 Google Scholar.
page 108 note 4 A. M. Lévy and A. Lacroix, 'Les Minéraux des Roches,' 1888, p. 265.
page 108 note 5 G. Tschermak, Min. Mitt., 1871, p. 29.
page 108 note 6 Wülfing, E. A., Min. Petr. Mitt., 1896, vol. xv, pp. 29–48 Google Scholar.
page 109 note 1 Galkin, X., Neues Jahrb. Min., 1910, Beil.-Bd. xxix, pp. 681–718 Google Scholar.
page 109 note 2 Quoted in H. Rosenbusch, 'Elemente der Gesteinslehre,' 1910, 8rd edit., p. 445.
page 109 note 3 Schmidt, W. B., Min. Petr. Mitt, 1882, vol. iv, p. 14 Google Scholar.
page 109 note 4 E. A. Wülfing, loc. cit.
- 2
- Cited by