Hostname: page-component-848d4c4894-r5zm4 Total loading time: 0 Render date: 2024-06-22T02:27:04.723Z Has data issue: false hasContentIssue false

Co-existing Pyroxenes: Some Causes of Variation and Anomalies in the optically Derived Compositional Tie-Lines, with Particular Reference to Charnockitic Rocks

Published online by Cambridge University Press:  01 May 2009

Allan F. Wilson
Affiliation:
Dept. of Geology and Mineralogy, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia.

Abstract

Available data from charnockitic rocks (including twenty-eight new pyroxene pairs fromAustralia) suggest that a major cause of variation in optically derived compositional tie-line trends of co-existing pyroxenes is related to the geothermal history of the rocks concerned. It may yet be possible to subdivide the granulite facies, and also to detect mineral instability by critical study of tie-line trends. Recommendations are made whereby mineralogic and structural studies of charnockitic rocks can be integrated to yield more reliable chemical and optical data.

Type
Articles
Copyright
Copyright © Cambridge University Press 1960

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

REFERENCES

de Vore, G. W., 1957. The association of strongly polarizing cations with weakly polarizing cations as a major influence in element distribution, mineral composition, and crystal growth. Journ. Geol., lxv, 178195.CrossRefGoogle Scholar
Eskola, P., 1952. On the granulites of Lapland. Amer. Journ. Sci., Bowen Volume, 133171.Google Scholar
Hess, H., 1941. Pyroxenes of common mafic magmas, part 2. Amer. Min., xxvi, 573594.Google Scholar
Hess, H., 1949. Chemical composition and optical properties of common clinopyroxenes, part 1. Amer. Min., xxxiv, 621666.Google Scholar
Hess, H., 1952. Orthopyroxenes of the Bushveld type, ion substitutions and changes in unit cell dimensions. Amer. Journ. Sci., Bowen Volume, 173187.Google Scholar
Hietanen, A., 1947. Archean geology of the Turku District in south-western Finland. Bull. Geol. Soc. Amer., lviii, 10191084.CrossRefGoogle Scholar
Hori, F., 1956. Effects of constituent cations on the refractive indices of orthopyroxenes. Mineral. Journ. Japan, i, 359371.CrossRefGoogle Scholar
Howie, R. A., 1955. The geochemistry of the charnockite series of Madras, India. Trans. Roy. Soc. Edin., lxii, 725768.CrossRefGoogle Scholar
Howie, R. A., and Subramaniam, A. P., 1957. The paragenesis of garnet in charnockite, enderbite, and related granulites. Mineral Mag., xxxi, 565586.Google Scholar
Muir, I. D., and Tilley, C. E., 1958. The compositions of co-existing pyroxenes in metamorphic assemblages. Geol. Mag., xcv, 403408.CrossRefGoogle Scholar
Parras, K., 1958. On the charnockites in the light of a highly metamorphic rock complex in south-western Finland. Bull. Comm. Géol. Finlande, clxxxi.Google Scholar
Rothstein, A. T. V., 1958. Pyroxenes from the Dawros Peridotite and some comments on their nature. Geol. Mag., xcv, 456462.CrossRefGoogle Scholar
Subramaniam, A. P., 1956. Mineralogy and petrology of the Sittampundi Complex, Salem District, Madras State, India. Bull. Geol. Soc. Amer., lxvii, 317390.CrossRefGoogle Scholar
Wilson, A. F., 1957. Some structural notes on charnockitic rocks. Bull. Mysore Geol. Assoc., xiii.Google Scholar
Wilson, A. F., 1958. Advances in the knowledge of the structure and petrology of the Precambrian rocks of south-western Australia. Journ. Roy. Soc. W. Austr., xli, 5783.Google Scholar
Wilson, A. F., 1959 a. The charnockitic rocks of Australia. Geol. Rund., xlvii, 491510.CrossRefGoogle Scholar
Wilson, A. F., 1959 b. The charnockitic granites and associated granites of Central Australia. Trans. Roy. Soc. S. Australia., lxxxiii (in press).Google Scholar