P–T CONDITIONS, U/Pb AND 40Ar/39Ar ISOTOPIC AGES OF UHT GRANULITES FROM CAPE KALTYGEI, WESTERN BAIKAL REGION
| Autor: | E. I. Mikheev, V. V. Khlestov, A. V. Travin, Alexander Vladimirov, A. S. Mekhonoshin, N. I. Volkova |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
cape kaltygei Science Geochemistry 010502 geochemistry & geophysics Granulite 01 natural sciences p–t pseudosections Geophysics u-pb and ar-ar geochronology Cape western baikal region Geology uht granulites 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Geodinamika i Tektonofizika, Vol 12, Iss 2, Pp 310-331 (2021) |
| Popis: | The study is focused on metapelitic granulites of Cape Kaltygei (Western Baikal region) that contain a diagnostic mineral assemblage of ultrahigh temperature (UHT) metamorphic rocks (orthopyroxene+sillimanite+quartz). The pseudosection-based thermobarometry yields peak metamorphic temperature and pressure values (T=950 °C, P=~9 kbar) and suggests near-isobaric cooling (IBC) conditions during the retrograde evolution of the granulites. The U/Pb zircon age estimates for metamorphism (~1.87 Ga) support the data published by other researchers. The SHRIMP-II U-Pb dating of zircon cores yields a minimum protolith age of 1.94–1.91 Ga. Biotites and amphiboles from granulites of Cape Kaltygei show the 40Ar/39Ar isotopic ages that are close to the Early Paleozoic accretion-collision system of the Western Baikal region. |
| Databáze: | OpenAIRE |
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