Tectonic discrimination of siliciclastic sedimentary record of the northern Tethyan margin at the end of the Triassic

Abstract

Tectonic setting of both the uppermost Triassic Tomanová and the lowermost Jurassic Dudziniec formations can be characterized by a series of diagnostic discrimination diagrams. High-silica and low-silica multi-dimensional diagrams indicate that the sediments could have been deposited in the continental collision/rift setting. Diagrams of K₂O/Na₂O versus SiO₂, SiO₂/Al₂O₃versus K₂O/Na₂O and Th-Co-Zr/10 as well as Th-Sc-Zr/10 determine an origin from the tectonically active and/or passive continental margin setting. REE parameters indicate predominantly a passive margin tectonic setting of the sediments. The most probable source of clastic admixture in the Scythian to Domerian sediments in the Tatric Unit was situated in a remnant of the Variscan collisional orogen – the Vindelician Highlands. Occasional monsoonal rains occurring in orbitally controlled cycles transported weathered material from the source area down river valleys on the seaward slopes of the Variscan Vindelician Mountains towards the Tethyan Sea. The input of this material influenced also the marginal parts of the Fatricum (e.g., Vysoká or Havran units).