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Feldspars from the Meldon aplite, Devonshire, England

Published online by Cambridge University Press:  05 July 2018

M. Nawaz Chaudhry
M. Nawaz Chaudhry*
Affiliation:
Department of Geology, University of the Panjab, Lahore, West Pakistan
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Summary

Chemical analyses of nine K-feldspars and thirteen albites, along with their optical, physical, and X-ray data are presented. The obliquity values Δ = 12·5(d131-d13¯1) of the K-feldspars are found to be independent of the contents of silica and volatiles in the rocks. The role of temperature as the primary factor affecting the obliquity values is stressed. The relationship between the (An + Ab) content of the potassic phase of K-feldspars and 2Vα is shown diagrammatically.

Type
Research Article
Information
Mineralogical Magazine , Volume 38 , Issue 294 , June 1971 , pp. 179 - 185
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Bowen, (N.L.) and Tuttle, (O.F.), 1950. The system NaAlSi3O8KA1Si3O8-H2O. Journ. Geol. 58, 489.511 [M.A. 11-325].Google Scholar
Dietrich, (R.V.), 1962. K-feldspar structural states as petrogenetic indicators. Norsk Geol. Tidsskr. 42, 394.414 [M.A. 16-462].Google Scholar
Eskola, (P.), 1951. Around Pitkäranta. Ann. Acad. Sci. Fennicae, ser. A.3, no. 27 [M.A. 11-471].Google Scholar
Goldsmith, (J.R.) and Laves, (F.), 1954a. The microcline-sanidine stability relations. Geochimica Acta, 5, 1–19 [M.A. 12-333].CrossRefGoogle Scholar
Goldsmith, (J.R.) and Laves, (F.), 1954b. Potassium-feldspars Structurally intermediate between microcline and sanidine. Ibid. 6, s-18 [M.A. 12-527].Google Scholar
Orville, (M.P.), 1958. Feldspar investigations. Carnegie Inst. Washington, Year Book, 57, 206.9.Google Scholar
Orville, (M.P.), 1960. Powder X-ray methods for determination of (Abq-An) content of microcline. Bull. Geol. Soc. Amer. 71, 1939.40 (abstr.).Google Scholar
Orville, (M.P.), 1963. Alkali ion exchange between vapor and feldspar phases. Amer. Journ. Sci. 261, 20.-37 [M.A. 16-435].Google Scholar