Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-05T09:23:40.717Z Has data issue: false hasContentIssue false
  • English
  • Français

High chromium and vanadium in andalusite, phengite and retrogressive margarite in contact metamorphosed Ba-rich black slate from the Abercrombie Beds, New South Wales, Australia

Published online by Cambridge University Press:  05 July 2018

Vincent J. Morand
Vincent J. Morand*
Affiliation:
Department of Geology and Geophysics, University of Sydney, N.S.W. 2006, Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

Graphitic, quartz-rich black slate within the Late Ordovician Abercrombie Beds, Lachlan Fold Belt, southeast Australia, has undergone contact metamorphism adjacent to the Siluro-Devonian Wyangala Batholith. This produced porphyroblasts of andalusite and cordierite, and smaller grains of pale green phengitic mica. Later regional metamorphism caused complete retrogression of cordierite and partial retrogression of andalusite, with margarite replacing some andalusite.

The aluminous minerals andalusite, margarite and phengite all contain V and Cr substituting for Al. Andalusite has up to 1.39% V2O3 and 1.09% Cr2O3, margarite has up to 1.07% V2O3 and 0.37% Cr2O3, and phengitic mica has up to 6.93% V2O3 and 1.52% Cr2O3. This mica also has BaO contents of up to 1.96%.

Chemical analyses reveal very high SiO2 contents for these rocks (about 89%), carbon contents of about 2%, and extremely low CaO, FeO, MgO and Na2O. Although V and Cr are prominent in aluminous minerals, their concentrations in the rock are only about average for black shales. However, Ba values range from 2000 to 6000 p.p.m., well above average for black shales. It is suggested that V and Cr probably precipitated from sea water, but Ba may have been concentrated by planktonic organisms such as radiolaria.

Keywords

black slateandalusitemicabariumvanadium
Type
Silicate Mineralogy
Information
Mineralogical Magazine , Volume 54 , Issue 376 , September 1990 , pp. 381 - 391
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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.)

Footnotes

*

Present address: Department of Geology, James Cook University, Townsville, Qld 4811, Australia

References

Berry, W. B. N., Wilde, P., Quinby-Hunt, M. S. and Orth, C. J. (1986) Norsk Geol. Tidds. 66, 45-51.Google Scholar
Carlson, W. D. and Rossman, G. R. (1988) Am. Mineral. 73, 1366-9.Google Scholar
Cas, R. A. F. (1983) A review of the palaeogeographic and tectonic development of the Palaeozoic Lachlan Fold Belt of south eastern Australia. Geol. Soc. Austral. Spec. Publ. No. 10.Google Scholar
Chinner, G. A., Smith, J. V. and Knowles, C. R. (1969) Am. J. Sci. 267A, 96–113.Google Scholar
Deer, W. A., Howie, R. A. and Zussman, J. (1962) Rock-forming Minerals, Vol. 3, Sheet Silicates, John Wiley, New York.Google Scholar
Deer, W. A., Howie, R. A. and Zussman, J. (1982) Rock-forming Minerals, Vol. 1A, Orthosilicates. 2nd ed. Longman, London.Google Scholar
Goldberg, E. D. (1957) In Ecology (Hedgpeth, J. W., ed.. Geol. Soc. Am. Mem. 67, 1: 345-57.Google Scholar
Gray, D. R. (1979) Am. J. Sci. 279, 97-128.CrossRefGoogle Scholar
Guidotti, C. V. (1984) In Micas. Reviews in Mineralogy, Vol. 13 (Bailey, S. W., ed.. Mineral. Soc. Am., 357-467.Google Scholar
Holland, H. D. (1979) Econ. Geol. 74, 1676-80.CrossRefGoogle Scholar
Joplin, G. A. (1945) Proc. Linn. Soc. N.S.W. 70, 158-72.Google Scholar
Morand, V. J. (1984) Ph.D. thesis, University of Sydney.Google Scholar
Morand, V. J. (1987) Austral. J. Earth Sci. 34, 119-33.CrossRefGoogle Scholar
Morand, V. J. (1988a) Ibid. 35, 339-53.CrossRefGoogle Scholar
Morand, V. J. (1988b) Mineral. Mag. 52, 341-5.CrossRefGoogle Scholar
Packham, G. H. (1969) In Geology of New South Wales (Packham, G. H., ed.. J. Geol. Soc. Austral. 16, 76-103.Google Scholar
Powell, C. McA. (1983) Ibid. 30, 353-74.Google Scholar
Sehreyer, W., Werding, G. and Abraham, K. (1981) J. Petrol. 22, 191-231.CrossRefGoogle Scholar
Snetsinger, K. G. (1966) Am. Mineral. 51, 1623-39.Google Scholar
Vine, J. D. and Tourtelot, E. B. (1970) Econ. Geol. 65, 253-72.CrossRefGoogle Scholar
Vinogradova, Z. A. and Koval'skiy, V. V. (1962) Dokl. Acad. Nauk S.S.S.R. 147, 1458.Google Scholar
Winkler, H. G. F. (1979) Petrogenesis of Metamorphic Rocks, 5th ed. Springer-Verlag, New York.Google Scholar