The South Carpathians: Tectono-metamorphic units related to Variscan and Pan-African inheritance

Abstract

This overview of the pre-Mesozoic tectono-stratigraphic units from the South Carpathian basement is based on updating the published and unpublished maps with recent age determinations. Updating is focused on pre-Upper Carboniferous metamorphosed sequences and related magmatites, which yielded protoliths ages in the Neoproterozoic to Carboniferous time span. Within the Danubian Domain, the Upper Proterozoic (Pan-African/Cadomian) granitoid massifs are intruded in the metaterrigenous Lainici-Păiuş unit, while Paleozoic (Carboniferous and Lower Permian) granitoids and volcanics are present in both Neoproterozoic units, Lainici-Păiuş and Drăgşan (oceanic type rock assemblages). A Devonian ophiolitic and tectonic paleosuture separating these two units is preserved in the Danubian Domain. In the Getic-Supragetic Domain, Neoproterozoic protoliths are recognised in the Lotru and Ursu units, Cambrian protoliths in the Făgăraș unit, while Lower Paleozoic (Ordovician) metagranitoids are associated to the Cumpăna and Sebeș units. Variscan tectonic lines are cartographically identified based on simple shear zones and syn-tectonic parageneses, contrasting lithologies, structural-metamorphic features and the recognized paleosutures. The main feature of the gneissic units in the Getic-Supragetic basement is the exhumation of the deep seated shear zones and HP mafic-ultramafic rocks with Carboniferous izotopic ages, as well as the widespread metatectic migmatisation and anatexis.