Abstract

Along the base of the Brenner Mesozoic (Central Alps, Austria), the topmost part of the Oetztal-Stubai crystalline complex displays a zone of Fe- and Al-rich phyllitic schists. Field relations and geochemical and mineralogical data suggest that this zone is a paleo-weathering horizon, which was overprinted at higher greenschist grade during Alpidic regional metamorphism. Considering the overlying elastic sedimentary rocks and the mode of occurrence, a hydrothermal-metasomatic origin of the alteration zone can be excluded. Dating of the basement uplift and event-stratigraphic correlations of the overlying elastic rocks with unmetamorphosed sedimentary rocks of the Northern and Southern Alps imply a middle to late Scythian age (Early Triassic) of the weathering. A combination of structural, petrographic, and stratigraphic data to correlate such horizons, especially in metamorphic terranes, is necessary for reconstructing the paleoenvironment and solving tectonic problems.

You do not currently have access to this article.