Hostname: page-component-7479d7b7d-fwgfc Total loading time: 0 Render date: 2024-07-10T20:32:54.987Z Has data issue: false hasContentIssue false

On hour-glass sector zoning in clinopyroxene

Published online by Cambridge University Press:  05 July 2018

A. K. Ferguson*
Affiliation:
School of Geology, University of Melbourne, Parkville, Victoria, Australia, 3052

Summary

The observations of hour-glass sector zoning from four selected clinopyroxenes in undersaturated lavas best fit a model in which the sector zoning is formed due to a structural requirement in a growth direction normal to {100} where a high concentration of silicate units, required to build the silicate chains, is unsatisfied. In these sectors Al substitutes for Si, the charge balance being maintained by octahedral substitutions, of which Ti contributes to the deeper colour of the sectors. The presence of concentric zoning only reflects a change in temperature and a change in the composition of the liquid during crystallization of the pyroxene.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1973

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

Binns, (R. A.), Duggan, (M. B.), and Wilkinson, (J. F. G.), 1970. Amer. Journ. Sci., 269, 132.CrossRefGoogle Scholar
Brauns, (R.), 1908. The Mineral Kingdom. Stuttgart (Lehmann).Google Scholar
Buckley, (H. E.), 1951. Crystal Growth. New York (Wiley).Google Scholar
Deer, (W. A.), Howie, (R. A.), and Zussman, (J.), 1963. Rock-forming Minerals, 2. London (Longmans).Google Scholar
De Neufville, (J.) and Schairer, (J. F.), 1961. Carnegie Inst. Washington, Yearbook, 61, 56.Google Scholar
Le Bas, (M. J.), 1962. Amer. Journ. Sci., 260, 267–88.CrossRefGoogle Scholar
Manning, (P. G.) and Nickel, (E. H.), 1969. Canad. Min., 10, 71.Google Scholar
O'Reilly, (S. Y.), 1972. Abstracts, Joint Specialist Groups Meetings. Canberra, Australia, A9.Google Scholar
Schorer, (G.), 1970. Neues Jahrb. Min. Monatsh., 310.Google Scholar
Strong, (D. F.), 1969. Min. Mag., 37, 472.CrossRefGoogle Scholar
Verhoogen, (J.), 1962. Amer. Journ. Sci., 260, 211.CrossRefGoogle Scholar
Verma, (A. R.) and Krishna, (P.), 1966. Polymorphism and polytypism in crystals. New York (Wiley).Google Scholar
Yagi, (K.) and Onuma, (K.), 1967. Hokkaido Univ. Fac. Sci. Journ. ser. 3, 13, 463.Google Scholar