Hostname: page-component-77c89778f8-7drxs Total loading time: 0 Render date: 2024-07-24T21:12:22.753Z Has data issue: false hasContentIssue false

The optical properties and composition of the acmitic pyroxenes

Published online by Cambridge University Press:  14 March 2018

P. A. Sabine*
Affiliation:
Geological Survey and Museum, London, 1

Extract

The occurrence of acmitic pyroxenes in the post-Cambrian intrusions of the north-west of Scotland was first noted by Teall (Home and Teall, 1892) who recorded aegirine in two dikes discovered by Gunn in the Coigach district of Ross-shire, and aegirine-augite in the borolanite of the Cnoc-na-Srbine mass. Since then, acmitic pyroxenes have been recorded by Teall (1900) from the Assynt felsites, Shand (1910) from dikes of the border zone of Cnoc-na-Srbine, and Phemister (1926) from the dikes and plutonic rocks of the Loch Ailsh laccolite.

Having undertaken a comprehensive examination, in the field and in the laboratory, of the post-Cambrian sills and dikes of the Assynt district, the writer determined some of the optical constants of the acmitic pyroxenes of these intrusions. Arising from this work the considerable data now available on the acmitic pyroxenes has been reviewed. A chemical analysis has also been carried out, and it is hoped that the information assembled and re-interpreted here may be of some general interest.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1950

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

Adamson, (O.J.), 1944. The petrology of the Norra Käirr district. An occurrence of alkaline rocks in southern Sweden. Geol. För. Förh. Stockholm, vol. 66, pp. 113-255 (p. 135). [M.A. 9–87.]Google Scholar
Alling, (H.L.), 1921. The mineralography of the feldspars. Journ. Geol. Chicago, vol. 29, pp. 193294. [M.A. 3- 33.]Google Scholar
Berman, (H.), 1937. Constitution and classification of the natural silicates. Amer. Min., vol. 22, pp. 342408.Google Scholar
Berzelius, (J.), 1835. Neues Jahrb. Min., p. 184.Google Scholar
Evans, (R.C.), 1939. An introduction to crystal chemistry. Cambridge. [M.A. 7–311.]Google Scholar
Goranson, (R.W.), 1927. Aegiritc from Libby, Montana. Amer. Min., vol. 12, pp. 37-39. [M.A. 3–455.]Google Scholar
Horse, (J.) and Teall, (J. J. H.), 1892. On borolanite-?an igneous rock intrusive in the Cambrian limestone of Assynt, Sutherlandshire, and the Torridon sandstone of Ross-shire. Trans. Roy. Soc. Edinburgh, vol. 37, pp. 163 178.Google Scholar
Larsen, (E.S.), 1942. Alkalic rocky of Iron Hill, Gunuison County, Colorado. Prof. Paper, U.S. Geol. Surv., 197 A. [M.A. 9–174.]Google Scholar
Maconeoor, (M.) and Phemister, (J.), 1937. Geological excursion guide to the Assynt district of Suthcrland. Edinburgh Geol. Soc., 1937.Google Scholar
Nockolds, (S.R.) and Mitchell, (R.L.), 1948. The geochemistry of some Caledonian plutonic rocks: a study in the relationship between the major and trace elements of igneous rocks and their mim'rals. Trans. Roy. Soc. Edinburgh, vol. 61, pp. 533–575. [M.A. 19 424.]Google Scholar
Pecora, (W.T.), 1942. Nepheline syenite pcgmatitcs, Rocky Boy stock, Bearpaw Mountains, Montana. Amer. Min., vol. 27, pp. 397-424. [M.A. 9–173.]Google Scholar
Phemister, (J.), 1926. Strath Oykell and Lower Loch Shin. Mem. Geol. Surv.Google Scholar
Rogers, (A.F.) and Kerr, (P.F.), 1933. Thin-section mineralogy. New York. [M.A. 5–433.]Google Scholar
Rosenbusch, (H.), 1892. Mikrosk. Physiogr., vol. 1, p. 537.Google Scholar
Shard, (S.J.), 1910. On borolanite and its associates in Assynt. Trans. Edinburgh Geol. Soc., vol. 9, pp. 376416.Google Scholar
Ström, (P.), 1821. UndersSkning af ett nytt fossil. K. Vet. Acad. Handl. Stockholm, p. 160; Berzelius, (J.), ibid., p. 163.Google Scholar
Teall, (J. J. H.), 1900. Nepheline-syenite and its associates in the north-west of Scotland. Geol. Mug., dec. 4, vol. 7, pp. 385392.Google Scholar
Tscnermak, (G.), 1872. Ueber Pyroxen und Amphibot. Min. Mitt., for 1871. p. 17 (also in Jahrb. Geol. Reichsanstalt, Wien, 1872. vol. 21, for 1871).Google Scholar
Walker, (T.L.) and Parsons, (A.L.), 1926. Minerals from the nepheline syenite area, French river, Ontario. Univ. Toronto Studies, Geol. Ser., no. 22, pp. 514. [M.A. 3–302.]Google Scholar
Warren, (B.E.) and Biscoe, (J.), 1931. The crystal structure of the monoelinic pyroxenes. Zeits. Krist., vol. 80, pp. 391-401. [M.A. 5–186.]Google Scholar
Washington, (H.S.) and Merwin, (H.E.), 1927. The aemitie pyroxenes. Amer. Min., vol. 12, pp. 233252. [M.A. 3–374,]Google Scholar
Winchell, (A.N.), 1933. Elements of optical mineralogy, vol. 2, p. 223. [M.A. 5–337.]Google Scholar
[Zavaritzky (A. N.)] (A. H.), 1946. [An interesting example of a syenite-pegmatite from Ilmen Mountains.] . [Problems in mineralogy, geochemistry, and petrography. Fersman memorial volume], Moscow and Leningrad (Acad. Sei. U.S.S.R.), pp. 319-325. [M.A. 16-433.]Google Scholar