The Lepontine Area, a Geochronological Summary

  • V. Köppel

Abstract

Within the subcontinental mantle of the Lepontine area evidence for a 1725-Ma-old magmatism is still preserved. The formation of oceanic crust and island arcs started about 1000 Ma ago. Orthogneisses constitute the dominating rock type of the area. The majority of them are of Variscan age, but some are of Caledonian origin. The depositional age of the pre-Permian metasediments is not well contrained. Zircon U-Pb ages of metapsammites and metapsephites indicate that some of the pre-Variscan metasediments were deposited after the emplacement of the Caledonian granites. It seems reasonable to assume that also pre-Orodovician metasediments are present.

Keywords

Permian Crystallization Zircon Petrol Subduction 

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© Springer-Verlag Berlin Heidelberg 1993

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  • V. Köppel

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