Structural, lithostratigraphic and thermal features of a Permian lower crust from the Western Italian Alps (Valpelline Series, Valle d’Aosta)
Articolo
Data di Pubblicazione:
2024
Citazione:
Structural, lithostratigraphic and thermal features of a Permian lower crust from the Western Italian Alps (Valpelline Series, Valle d’Aosta) / F. Caso, A. Strambini, M. Zucali. - In: GEOLOGICAL MAGAZINE. - ISSN 1469-5081. - (2024), pp. 1-27. [Epub ahead of print] [10.1017/S0016756824000037]
Abstract:
The Valpelline Series (Dent-Blanche Tectonic System, Western Italian Alps) is a sector of lower continental crust, which consists of Permian migmatitic metapelite with different mineral
assemblages (i.e., garnet-, cordierite- and orthopyroxene-bearing), minor amphibolite and marble, intruded by aplite and pegmatite. Widespread melt production in metapelite and locally
in amphibolite occurred during the development of the regional foliation. The P–T conditions
during migmatisation, estimated using conventional geothermobarometers, range between
800–900 °C and 0.5–0.8 GPa, with a difference of up to ~50 °C between cordierite- and
orthopyroxene-bearing migmatites, the latter reaching higher temperatures. The Valpelline
Series shows rock types, metamorphic assemblages, P–T conditions and published ages of high temperature regional metamorphism like the archetypal lower crust section of the Ivrea-
Verbano Zone in the Southern Western Alps. The latter likely represents an external portion of
the same extending lower crust, at the onset of the Tethyan rifting due to lithospheric extension and asthenospheric rising.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
partial melting; migmatite; high-temperature metamorphism; Austroalpine;
Elenco autori:
F. Caso, A. Strambini, M. Zucali
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