التفاصيل البيبلوغرافية
| العنوان: |
Magnetic susceptibility of Variscan granite-types of the Spanish Central System and the redox state of magma |
| المؤلفون: |
VILLASECA, C., RUIZ-MARTÍNEZ, V.C., PÉREZ-SOBA, C. |
| المصدر: |
Geologica Acta; Vol. 15 No. 4 (2017): Granites and Related Rocks. A tribute to Guillermo Corretgé; 379-394 ; 1696-5728 ; 1695-6133 |
| بيانات النشر: |
Universitat de Barcelona |
| سنة النشر: |
2017 |
| المجموعة: |
Revistes Científiques de la Universitat de Barcelona |
| مصطلحات موضوعية: |
Magnetic susceptibility, Granite type, Biotite chemistry, Oxygen fugacity |
| الوصف: |
Magnetic susceptibility (MS) has been measured in Variscan granites from central Spain. They yield values in the order of 15 to 180μSI units for S- and I-type granites, indicating that both types belong to the ilmenite series. Only samples from magnetite-bearing leucogranites from the I-type La Pedriza massif show high MS values, in the order of 500-1400μSI, reflecting the presence of this ferromagnetic mineral. Mineral chemistry of magmatic Fe-rich minerals (mainly biotite) suggests similar oxidation values for both granite types. MS values change in highly fractionated granites accordingly either with the presence of rare new Fe-oxide phases (some I-type leucogranites) or with the marked modal amount decrease of Fe-rich minerals (I- and S-type leucogranites). The redox state in highly fractionated granite melts is mostly controlled by magmatic processes that modify redox conditions inherited from the source region. Thus, the occurrence of magnetite or ilmenite in granites is primarily controlled by the oxidation state of the source material but also by the differentiation degree of the granite melt. The presence of magnetite in some Variscan I-type leucogranites might be a consequence of crystal fractionation processes in a more limited mafic mineral assemblage than in S-type granite melts. |
| نوع الوثيقة: |
article in journal/newspaper |
| وصف الملف: |
application/pdf |
| اللغة: |
English |
| العلاقة: |
http://revistes.ub.edu/index.php/GEOACTA/article/view/GeologicaActa2017.15.4.8/22398Test; http://revistes.ub.edu/index.php/GEOACTA/article/view/GeologicaActa2017.15.4.8Test |
| الإتاحة: |
http://revistes.ub.edu/index.php/GEOACTA/article/view/GeologicaActa2017.15.4.8Test |
| حقوق: |
Drets d'autor (c) 2017 Geologica Acta |
| رقم الانضمام: |
edsbas.C0F082A9 |
| قاعدة البيانات: |
BASE |
