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An anorthite-epidote-garnet-hornfels from Namaqualand, South Africa

Published online by Cambridge University Press:  14 March 2018

C. B. Coetzee
C. B. Coetzee*
Affiliation:
Geology Department, University of Cape Town
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Extract

The present communication deals with a calc-silicate hornfels of uncommon mineralogical and chemical composition. It may be tentatively referred to the deep-seated metamorphism of a marl, and on account of the shortage of analytical data pertaining to metamorphosed sediments of the calcareo-argillaceous type, a detailed investigation of a variety of this group seems justified.

Intercalated bands of anorthite-epidote-garnet-hornfels bordered bilaterally by pyroxene-bearing gneisses occur on the farms Zandfontein, Pella, and Klein Pella in the north-eastern part of the division of Namaqualand, South Africa (cf. geological map), On Klein Pella small exposures also extend intermittingly for approximately 1·5 miles due WNW.-ESE. of the amphibolite koppie situated on the northern boundary of the farm area. The bands exhibit a gentle pinch and swell structure with maximum widths of 15 to 41 inches, and the contact with the host rock is commonly marked by an epidotic fringe ¾ inch in thickness. In some cases the anorthite-epidote-garnet-rock is penetrated by parallel lenticles of pure quartz which may attain maximum breadths of 0·8 inch.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 26 , Issue 175 , December 1941 , pp. 134 - 139
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1941

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References

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