کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6439166 | 1638060 | 2012 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
An experimental study of H solubility in feldspars: Effect of composition, oxygen fugacity, temperature and pressure and implications for crustal processes
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
ژئوشیمی و پترولوژی
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چکیده انگلیسی
A series of experiments, with run durations of â¼100-240 h, have been carried out on H solubility in natural labradorite, albite and anorthoclase at 2-10 kbar and 700-850 °C, in equilibrium with different oxygen buffer materials: Fe-FeO, Ni-NiO, Re-ReO2 and Fe2O3-Fe3O4. Attainment of equilibrium water contents were examined by conducting experiments with different run-durations and by performing profile analysis along crystal core-to-rim paths. The annealed products generally show typical OH-related infrared absorption bands in the range 3700-2600 cmâ1: the spectra of the labradorite and anorthoclase are dominated by broad bands at â¼3300-3100 cmâ1, while the spectra of the albite consist of broad bands at â¼3100-3000 cmâ1 and sharp bands at â¼3600-3400 cmâ1. The measured H solubility, ranging from â¼80 to 285 ppm H2O, differs greatly between the feldspars with different chemical compositions, depends strongly on oxygen fugacity, and increases with increasing temperature and pressure. The H solubility is significantly higher, e.g., by a factor of â¼3 or even more, at very reducing conditions than at oxidizing conditions. The high H solubility of feldspar at reduced conditions indicates that, at least locally, the Earth's ancient deep continental crust was probably more hydrous than the modern one. Crustal dehydration can be caused by a change of oxygen fugacity and a corresponding change of water solubility in the constituent feldspar under isothermal conditions, without the requirement of high temperature and/or additional heat sources.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geochimica et Cosmochimica Acta - Volume 97, 15 November 2012, Pages 46-57
Journal: Geochimica et Cosmochimica Acta - Volume 97, 15 November 2012, Pages 46-57
نویسندگان
Xiaozhi Yang,