- Tytuł:
- Valences and site characteristics of iron in radioactive magmatic veins (Egypt): A Mössbauer and chemical study
- Autorzy:
- Hassan, Kamaleldin M.
- Powiązania:
- https://bibliotekanauki.pl/articles/2086502.pdf
- Data publikacji:
- 2010
- Wydawca:
- Polskie Towarzystwo Mineralogiczne
- Tematy:
-
Egypt
Mössbauer
peralkaline rocks
aegirine-augite
Fe-oxide phases
radioactive/rare metals - Opis:
- Radioactive veins in shear zones of the El-Seboah granite in Egypt with anomalous concentrations of Nd, Ce, Zr, Y, Nb, Sm, Th and U were studied by petrographic microscopy, x-ray diffraction, 57Fe Mössbauer and wet chemical methods. The veins are composed essentially of quartz, aegirine-augite and minor K-feldspar ± α-iron oxide (hematite) ± γ-iron oxide hydroxide (goethite). They likely represent late-stage felsic melt that was quenched and devitrified at high temperature to yield crystals and crystallites, and then subjected to low temperature alteration during which most of the K feldspar transformed to kaolinite and opal. Mössbauer parameters of the samples indicate that the existing Fe-bearing minerals are primary, with appreciable ordering in the Fe sites. The bulk-sample iron (ΣFe) contents are extremely high (12.3-22.4%). The extent of oxidation of the Fe has been found to be 100% by Mössbauer spectroscopy and 95.36-99.69% by a chemical method. These conditions of Fe enrichment and strong oxidation suggest that the veins are extreme differentiates of granite magmas where high states of oxygen fugacity prevailed.
- Źródło:
-
Mineralogia; 2010, 41, 1/2; 23--33
1899-8291
1899-8526 - Pojawia się w:
- Mineralogia
- Dostawca treści:
- Biblioteka Nauki
Artykuł