Contrasts between i- and s-type granitoids of the kosciusko batholith

R. Hine, I. S. Williams, B. W. Chappell, A. J R White, R. Hine, I. S. Williams

    Research output: Contribution to journalArticlepeer-review

    218 Citations (Scopus)

    Abstract

    Two distinct groups of granitoids occur on the eastern side of the Kosciusko Batholith. Those considered to be derivatives of sedimentary source rocks (S-types) are usually foliated and either contain cordierite or white-mica secondary after cordierite. The granitoids produced from igneous source material (I-types) are generally massive and frequently contain hornblende. Geochemical parameters provide the best discriminant between the two groups, I-types have higher Ca, Al, Na2O/K2O, and Fe2O3/FeO, and lower Fe, Mg, Sc, V, Cr, Co, Ni, Cu, Zn, Ba, Rb, Th, La, Ce, and Y than S-types of comparable SiO2values. The differences between the two groups are not the result of differences in the melt-forming process but reflect differences in the nature of the source material. Thus the geochemical features of the S-type granitoids are indicative of their source rocks having been through a process of chemical weathering in a sedimentary cycle. Conversely, the I-type granitoids were derived from fractionated rocks that had not been involved in weathering processes.

    Original languageEnglish
    Pages (from-to)219-234
    Number of pages16
    JournalJournal of the Geological Society of Australia
    Volume25
    Issue number3-4
    DOIs
    Publication statusPublished - 1978

    Fingerprint

    Dive into the research topics of 'Contrasts between i- and s-type granitoids of the kosciusko batholith'. Together they form a unique fingerprint.

    Cite this