Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-02T22:48:50.811Z Has data issue: false hasContentIssue false
  • English
  • Français

A granophyre from Coire Uaigneich, Isle of Skye, containing quartz paramorphs after tridymite (Plate XIII)

Published online by Cambridge University Press:  14 March 2018

L. R. Wager ,
D. S. Weedon  and
E. A. Vincent
L. R. Wager
Affiliation:
Department of Geology and Mineralogy, University Museum, Oxford
D. S. Weedon
Affiliation:
Department of Geology and Mineralogy, University Museum, Oxford
E. A. Vincent
Affiliation:
Department of Geology and Mineralogy, University Museum, Oxford
Get access Rights & Permissions [Opens in a new window]

Extract

The narrow belt of granophyre lying to the west of Blaven in the Isle of Skye showed so admirably the effects of chilling that a series of specimens was collected by one of us (L.R.W.) and found to contain, in the chilled marginal rock, phenoerysts of tridymite, now inverted to quartz. In the Thulean Tertiary igneous province former tridymite is known from certain acid lavas, for example, the Tardree rhyolite (von Lasaulx, 1877) and certain Icelandic liparites (Hawkes, 1916), and from metamorphosed arkoses adjacent to basic igneous intrusions (Harker, 1908, 1932), but it has not previously been noted in the intrusive acid rocks. In addition to phenocrysts of tridymite inverted to quartz, there is present in the groundmass of the unchilled granophyre a second generation of inverted tridymite crystals, surrounded by a final stage of quartz and felspar which has crystallized with normal microgranitic textures. Some of the textural features resemble those of the normal Skye granophyres, while others resemble certain metamorphosed arkoses.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 30 , Issue 223 , December 1953 , pp. 263 - 276
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1953

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barth, (T. F. W.), 1952. Theoretical petrology. New York, p. 128. [M.A. 11-514.]Google Scholar
Carr, (J. M.), 1952. An investigation of the Sgurr na Stri-Druim Hain sector of the basic igneous complex of the Cuillin Hills, Isle of Skye. Unpublished thesis, Oxford, 1952.Google Scholar
Fenner, (C. N.), 1913. The stability relations of the silica minerals. Amer. Journ. Sci., ser. 4, vol. 36, pp. 331-384.Google Scholar
Harker, (A.), 1904. The Tertiary igneous rocks of Skye. Mem. Geol. Surv, Scotland, p. 153.Google Scholar
Harker, (A.) 1908. The small isles of Inverness-shire. Mem. Geol. Surv. Scotland, p. 61-67.Google Scholar
Harker, (A.) 1932. Metamorphism. London, p. 68.Google Scholar
Hawkes, (L.), 1916. On tridymite and quartz after tridymite in Icelandic rocks. Geol. Mag., dec. 6, vol. 3, pp. 205-209. [M.A. 1-58.]Google Scholar
Hess, (H.), 1952. Orthopyroxenes of the Bushveld type, ion substitution and changes in unit cell dimensions. Amer. Journ. Sci., Bowen volume, pp. 173-187. [M.A. 12-97.]Google Scholar
Holmes, (A.), 1936. A record of new analyses of Tertiary igneous rocks. Proc. Roy. Irish Acad., vol. 43B, pp. 89-94. [M.A. 7-189.]Google Scholar
Larsen, (E. S.), Irving, (J.), Gonyer, (F. A.), and Larsen, (E. S., 3rd), 1936. Petrologic results of a study of the minerals from the Tertiary volcanic rocks of the San Juan region, Colorado. Amer. Min., vol. 21, p. 687. [M.A. 7-31.]Google Scholar
Lasaulx, (A. VON), 1877. On the discovery of tridymite in the trachyte porphyry of Co. Antrim. Journ. Roy. Geol. Soc. Ireland, new ser., vol. 4, p. 227.Google Scholar
MacGregor, (A. G.), 1938. The volcanic history and petrology of Montserrat, with observations on Mt. Pelé in Martinique, Phil. Trans. Roy. Soc. London, ser. B, vol. 229, pp. 58-61.Google Scholar
Poldervaart, (A.), 1947. The relationship of orthopyroxene to pigeonite. Min. Mag., vol. 28, pp. 164-172.Google Scholar
Ray, (L. L.), 1947. Quartz paramorphs after tridymite from Colorado. Amer. Min., vol. 32, p. 646. [M.A. 10-384.]Google Scholar
Richey, (J. E.), 1932. Tertiary ring structures in Great Britain. Trans. Geol. Soc. Glasgow, vol. 19, pp. 42-140 (comment on p. 75).Google Scholar
Schairer, (J. F.), 1950. The alkali-feldspar join in the system NaA1SiO4-KAlSiO4-SiO2 . Journ. Geol. Chicago, vol. 58, pp. 512-517. [M.A. 11-325.]CrossRefGoogle Scholar
Tilley, (C. E.), 1949. An alkali facies of granite at granite-dolomite contacts in Skye. Geol. Mag. Hertford, vol. 86, pp. 81-93. [M.A. 11-395.]Google Scholar
Wager, (L. R.) and Deer, (W. A.), 1939. Petrology of the Skaergaard intrusion, Kangerdlugssuaq, east Greenland. Meddel. om Grønland, vol. 105, no. 4. [M.A. 8-27.]Google Scholar
Wells, (M. K.), 1951. Sedimentary inclusions in the hypersthene-gabbro, Ardnamurchan, Argyllshire. Min. Mag., vol. 29, p. 720.Google Scholar