Chemistry of biotite as a guide to the nature of magmas, Hajja granitoid complex. Yemen Republic
Biotites separated from Hajja granatic rocks, Yemen Republic, have been examined. The chemical data of 14 analysed biotites show that the biotites are ferrous iron varieties. The behaviour of major elements in the examined biotites discussed according to different variation diagrams and elemental ra...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
University of Szeged, Department of Mineralogy, Geochemistry and Petrology
Szeged
1995
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| Sorozat: | Acta mineralogica-petrographica
36 |
| Kulcsszavak: | Kőzettan, Ásványtan, Földtan |
| Tárgyszavak: | |
| Online Access: | http://acta.bibl.u-szeged.hu/24822 |
| Tartalmi kivonat: | Biotites separated from Hajja granatic rocks, Yemen Republic, have been examined. The chemical data of 14 analysed biotites show that the biotites are ferrous iron varieties. The behaviour of major elements in the examined biotites discussed according to different variation diagrams and elemental ratios. The significance of Fe(1) (Fe(1,+Mg) ratio as a relative measure of biotite crystallization suggests that the biotites may be formed under a temperature range of 815'-950"C. In the present study since Fe shows little variation with A1 in biotites in both calc-alkaline and peralumios magmas, the substitution 2A1 -» 3Fe2 * does not play an important role during the crystallization of biotites in these two types. On the other hand the substitution 3Mg -> 2A1 is vital. The contrasting behaviour of Fe and Mg with respect to A1 during the crystallization of biotites is partly governed by the various physicochemical conditions including the behaviour of volatiles in these magmas. |
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| Terjedelem/Fizikai jellemzők: | 35-54 |
| ISSN: | 0365-8066 |