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| Titel: |
Contrasts between I- and S-type granitoids of the Kosciusko Batholith |
| Auteur: |
Hine, R. Williams, I. S. Chappell, B. W. White, A. J. R. |
| Verschenen in: |
Australian journal of earth sciences |
| Paginering: | Jaargang 25 (1978) nr. 3-4 pagina's 219-234 |
| Jaar: |
1978-06 |
| Inhoud: |
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 SiO2 values. 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. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 2 van 9 gevonden artikelen
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