An extensive record of orogenesis recorded in a Madagascar granulite
| العنوان: | An extensive record of orogenesis recorded in a Madagascar granulite |
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| المؤلفون: | Forrest Horton, Carl Swindle, Robert M. Holder |
| المصدر: | Journal of Metamorphic Geology. 40:287-305 |
| بيانات النشر: | Wiley, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Geochemistry and Petrology, Geochemistry, Geology, Granulite |
| الوصف: | We present a comprehensive petrological and geochronological study of a single granulite sample from the lithosphere-scale Beraketa shear zone in southern Madagascar to constrain the orogenic history of Gondwana assembly in this region. The studied sample provides a panoply of data constraining the prograde, retrograde, and late metasomatic history of the region via the application of Ti-in-quartz, Ti-in-zircon, Zr-in-rutile, and Al-in-orthopyroxene thermobarometry; phase-equilibrium modeling; U–Pb monazite, zircon, and rutile petrochronology; and trace element diffusion chronometry in rutile methods. Our results reveal five stages of metamorphism along a clockwise P-T path that may have begun as early as 620–600 Ma and certainly by 580–560 Ma, based on the oldest concordant zircon dates. The rock heated to >725 °C at less than 7.5 kbar (stage 1) before burial to ~8 kbar (stage 2). By c. 540 Ma, the rock had heated to ~970 °C at ~9 kbar, and lost approximately 12% melt (stage 3), before decompressing and cooling to the solidus at ~860 °C and 6.5 kbar within 10 Myr (stage 4). The vast majority of monazite and zircon dates record stage 4 cooling and exhumation. Monazite and zircon rim dates as young as c. 510 Ma record subsolidus cooling (stage 5) and associated symplectite formation around garnet. U–Pb rutile dates record partial resetting at c. 460 Ma; Zr- and Nb-in-rutile diffusion chronometry link these dates to a metasomatic event that lasted |
| وصف الملف: | application/vnd.ms-excel; application/pdf; application/msword |
| تدمد: | 1525-1314 0263-4929 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3f22b9fa2c4afc2ed4a83f5d8c521393 https://doi.org/10.1111/jmg.12628 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....3f22b9fa2c4afc2ed4a83f5d8c521393 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15251314 02634929 |
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