Evidence of Tethyan continental break-up and Alpine collision in the Argentera-Mercantour Massif, Western Alps
Articolo
Data di Pubblicazione:
2020
Citazione:
Evidence of Tethyan continental break-up and Alpine collision in the Argentera-Mercantour Massif, Western Alps / M. Filippi, D. Zanoni, J.M. Lardeaux, M.I. Spalla, G. Gosso. - In: LITHOS. - ISSN 0024-4937. - 372-373:(2020 Nov 01). [10.1016/j.lithos.2020.105653]
Abstract:
In the Argentera-Mercantour Massif, swarms of high-K calc-alkaline lamprophyres intruded into Carboniferous migmatites and early Permian granites, likely in Permian-Triassic times. The dykes collected multiple magmatic injections, the latest of which of alkaline affinity. Syn-intrusive vesicles and straight chilled margins suggest that the lamprophyres emplaced at a shallow crustal level.
Lower greenschist facies mineral assemblages replaced lamprophyre igneous minerals as a result of late-intrusive hydrothermal circulation that occurred soon after the dyke emplacement. The hydrothermal event is constrained at T=300–350°C and P < 0.1 GPa by matching thermobarometry and pseudosection results. During the Alpine collision, the lamprophyreswere intersected by upper greenschist faciesmylonitic shear zones developed at T= 420–450°C and P=0.2–0.4 GPa,which are the metamorphic peak conditions of the Argentera-MercantourMassif in Alpine times.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
High-K calc-alkaline lamprophyres; Permian-Triassic crustal thinning; Alpine collision; External crystalline Massifs; Helvetic-Dauphinois-Provençal domain
Elenco autori:
M. Filippi, D. Zanoni, J.M. Lardeaux, M.I. Spalla, G. Gosso
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