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The Occurrence of Orthoclase and Microcline in the Granitic Gneisses of the Carn Chuinneag-Inchbae Complex, E. Ross-shire

Published online by Cambridge University Press:  01 May 2009

R. I. Harker
R. I. Harker
Affiliation:
Mineral Sciences Building, Pennsylvania State College, Pennsylvania, U.S.A.
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Abstract

Optical examination of the potash feldspars in the granitic gneisses of the Carn Chuinneag-Inchbae complex suggests that both ortho-clase and microcline occur together—not infrequently in the same crystal. Optic axial and extinction angles, intermediate in value between those characteristic of the two polymorphs, have been recorded and plotted graphically. X-ray powder diffraction patterns confirm that both orthoclase and microcline are present together in these rocks. It is believed that most of the microcline developed from orthoclase during the regional metamorphism of the area, which permitted recrystallization at a lower temperature than that at which the orthoclase was formed.

Type
Articles
Information
Geological Magazine , Volume 91 , Issue 2 , April 1954 , pp. 129 - 136
Copyright
Copyright © Cambridge University Press 1954

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References

REFERENCES

Berg, R. R., 1952. Feldspathized sandstone. Journ. Sedimentary Petrology, xxii, 221.CrossRefGoogle Scholar
Buddington, A. F., 1939. Adirondack igneous rocks and their metamorphism. Geol. Soc. Amer. Mem., No. 7.Google Scholar
Chayes, F., 1952. On the association of perthitic microcline with highly undulant or granular quartz in some calc-alkaline granites. Amer. Journ. Sci., ccl, 281.CrossRefGoogle Scholar
Daly, R. A., 1917. Low temperature formation of alkaline feldspars, in limestone. Proc. Nat. Acad. Sci., U.S.A., iii, 659.CrossRefGoogle Scholar
Dolar-Mantuani, L., 1952. The feldspar in the intrusive rocks near Beaver-dell, B.C. Amer. Min., xxxvii, 492.Google Scholar
Eskola, P., 1952. On the granulites of Lapland. Amer. Journ. Sci., Bowen Volume, 133.Google Scholar
Goldich, S. S., 1934. Authigenic feldspar in sandstones of south-eastern Minnesota. Journ. Sedimentary Petrology, iv, 89.Google Scholar
Hinxman, L. W., and Grant-Wilson, J. S., 1902. The geology of lower Strathspey. Geol. Survey Mem.Google Scholar
Johannsen, A., 1932. A descriptive petrography of the igneous rocks, Vol. 2.Google Scholar
Laves, F., 1950. The lattice and twinning of microcline and other potash feldspars. Journ. Geol., lviii, 548.CrossRefGoogle Scholar
Laves, F., 1952. Phase relations of the alkali feldspars. Journ. Geol., lx, 436 and 549.CrossRefGoogle Scholar
Mackenzie, W. S., 1952. Optical and X-ray studies of alkali feldspars. Carnegie Institution of Washington Year Book, No. 51, 49.Google Scholar
Oftedahl, C., 1950. Petrology and geology of the Rondane area. Norsk. Geol. Tidskr., xxviii, 199.Google Scholar
Peach, B. N. et al. , 1912. The geology of Ben Wyvis, Carn Chuinneag, Inchbae, and the surrounding country. Geol. Survey Mem.Google Scholar
Read, H. H., 1923. The geology of the country around Banff, Huntly, and Turriff. Geol. Survey Mem.Google Scholar
Read, H. H., Phemister, J., and Ross, G., 1926. The geology of Strath Oykell and Lower Loch Shin. Geol. Survey Mem.Google Scholar
Tilley, C. E., 1935. The role of kyanite in the “ hornfels-zone ” of the Carn Chuinneag granite, Ross-shire. Miner. Mag., xxiv, 92.Google Scholar
Tuttle, O. F., 1952. Optical studies on alkali feldspars. Amer. Journ. Sci., Bowen Volume, 553.Google Scholar
Wilson, A. F., 1950. Some unusual alkali-feldspars in the Central Australian charnockitic rocks. Miner. Mag., xxix, 215.Google Scholar