The occurrence and origin of well-crystallised uvarovite garnet from the podiform chromitite deposits of south-eastern New South Wales

Abstract

Chromian garnets occur within three podiform chromitite deposits in south-eastern N.S.W. Fourteen new analyses of these garnets are presented in this paper and these reveal that the garnets are either uvarovite or chromian grossular in composition. These analyses, along with analyses of uvarovite garnets from other world occurrences, suggest that there is no distinct relationship between the composition of uvarovite garnets and the geological setting in which they occur. Although the composition of the chromium-bearing garnets from the two deposits which are examined in some detail in this paper are quite different, their environment of formation was similar. All of the Cr-bearing garnets have formed during calcium metasomatism congruent with localised remobilisation of chromium.