Ediacaran rocks from the Cadomian basement of the Saxo-Thuringian Zone (NE Bohemian Massif, Germany): age constraints, geotectonic setting and basin development

Abstract

This paper is focused on a compilation of known data from the low-grade metamorphosed rocks of the Ediacaran period in the German part of the Saxo-Thuringian Zone at the northeastern margin of the Bohemian Massif. The geotectonic setting during the formation of Ediacaran rock units is characterized by Cadomian orogenic processes from c. 650-540 Ma at the periphery of the West African Craton. The basin development during that time is characterized by the formation of a Cadomian backarc basin with a passive margin, and the outboard sitting Cadomian magmatic arc originated at c. 570-560 Ma. This arc-marginal basin system was formed on stretched continental crust in a strike-slip regime and reflects an active-margin setting in a style similar to the recent West Pacific. The backarc basin was closed between c. 560-540 Ma by the collision of the Cadomian magmatic arc with the cratonic hinterland: this resulted in the closure of the backarc basin and the formation of a Cadomian retroarc basin. Collision of an oceanic ridge with the Cadomian Orogenic Belt led to a slab break-off of the subducted oceanic plate resulting in an extreme heat flow, and a magmatic and anatectic event culminating at c. 540 Ma that was responsible for the intrusion of voluminous granitoid plutons.

Provenance of the early Palaeozoic volcano-sedimentary successions from eastern part of the Central Sudetes: implications for the tectonic evolution of the NE Bohemian Massif

“…The lack of HP conditions during Cadomian arc-continent collision and limited crustal thickening (e.g. Dörr et al 2002) are consistent with the inferred hot conditions of the KMB rhyolitic magma generation and correlate with intrusions into transitional crust at the peripheries of Gondwana that were postulated by tectonic model of Linnemann (2007) for the late Cambrian in the Saxothuringia (e.g. Zieger et al 2018).…”

“…12–14; e.g. Fernández-Suárez et al 2002; Linnemann, 2007; Linnemann et al 2008; Žáčková et al 2010; Drost et al 2011; Mazur et al 2012; Košler et al 2014; Strachan et al 2014; Soejono et al 2020). The youngest population of zircon grains recognized in the metasedimentary succession analysed from the DMC was probably derived from the erosion of Cambro-Ordovician granites widely exposed in the Saxothuringian (Zieger et al 2018 and references therein), Teplá-Barradian (e.g.…”

“…However, several detrital zircons were most probably supplied by volcano-sedimentary successions represented by, for example, the Stronie and Młynowiec formations in the Orlica-Śnieżnik dome (Jastrzębski et al 2010; Mazur et al 2012; Mazur et al 2015), the Zwethau and the Rothstein formations in the Saxohuringian zone (e.g. Elicki, 1997; Linnemann, 2007) or from glaciomarine sedimentary rocks documented in the Elbe zone and the North Saxon antiform in the southeastern part of the Saxothuringian zone (Linnemann et al 2018). Consequently, the anhedral Neoproterozoic zircons documented in the studied rocks may represent recycled material supplied by local sedimentary successions.…”

Drainage and environmental evolution across the Permo–Triassic boundary in the south‐east Germanic Basin (north‐east Bavaria)

“…Two tectonostratigraphic domains are recognized along the western BM: (i) the Moldanubian terrain (SE BM) (Fig. 2) consisting of pre‐Variscan paragneisses and granulites (Źák et al ., 2011) and metavolcanic/metasedimentary rocks; and (ii) the Saxo‐Thuringian terrain (NW BM) consisting of Ediacaran plutonic and volcano‐sedimentary rocks overlain by Cambrian to Early Carboniferous metasedimentary units and low to high‐grade metamorphic series (Linnemann, 2007; Wall et al ., 2019). Several north‐west/south‐east‐striking strike‐slip faults (for example, Franconian Line , Kulmbach Fault, Danube Fault and Pfahl Fault ) (Fig.…”

“…Palaeogeography of the Franconian Basin during the deposition of: (A) Rotliegend; (B) Zechstein; and (C) Buntsandstein (compiled from Freudenberger & Schwerd, 1996). The Bohemian Massif terrains are shown to the East (Linnemann, 2007). K‐E: Kulmbach–Eisfeld Fault (Wall et al ., 2019).…”