Development of a non-perennial to ephemeral fluvial system in continental fault-bounded basin – an example from the early Permian Krajanów Formation of the Intra-Sudetic Basin (NE Bohemian Massif)

Abstract

De vel op ment of a non-pe ren nial to ephem eral flu vial sys tem in con ti nen tal fault-bounded basin -an ex am ple from the early Perm ian Krajanów For ma tion of the Intra-Sudetic Ba sin (NE Bo he mian Mas sif). Geo log i cal Quar terly, 67: 31, doi: 10.7306/gq.1701 Non-pe ren nial to ephem eral flu vial sys tems dom i nated by sea sonal dis charge fluc tu a tions and ep i sodic rapid flood-flow events are typ i cal of arid to semi-arid cli ma tic con di tions. Dryland flu vial sys tems have been de scribed from many an cient and mod ern, pre dom i nantly tec toni cally-con trolled sed i men tary bas ins across the globe. This study pro vides de tailed sedimentological anal y sis and palaeoenvironmental in ter pre ta tion of the low er most part of the early Perm ian (?Asselian) Krajanów For ma tion ex posed within the con ti nen tal, fault-bounded Intra-Sudetic Ba sin (ISB), lo cated on the NE pe riph ery of Bo he mian Mas sif. High-res o lu tion sedimentological log ging and fa cies anal y sis in di cate that the early Perm ian flu vial system in this area was dom i nated by ephem eral flu vial pro cesses in flu enced strongly by a semi-arid to arid cli mate. Rapid (?cat a strophic) flood events led to ep i sodic sed i men ta tion of ver ti cally and lat er ally amal gam ated flu vial chan nel infills, with abun dant up per flow re gime struc tures as well as poorly channelized, lat er ally ex ten sive sheet-like bod ies of sand stone. The overbank de pos its are poorly pre served due to fre quent lat eral shift ing of the chan nels. Soft-sed i ment de for ma tion structures formed due to events of river bank col lapse as well as de bris flow fa cies point to high-en ergy, wan ing flows. It is concluded that de po si tion oc curred on broad, ter mi nal-type al lu vial fans, prob a bly in their prox i mal-to me dial seg ments within a dis trib u tive flu vial sys tem of the Perm ian Intra-Sudetic Ba sin. Petrographic com po si tion and mea sured palaeocurrent di rections show that the sed i ment was sourced from the neigh bour ing mas sifs -the Sowie Mts. Mas sif to the east, the Bardo Struc ture and a hy po thet i cal South ern Mas sif to the south/south-east.

A diadectid skin impression and its implications for the evolutionary origin of epidermal scales

“…Regarding the abundance and quality of preservation, the Piaskowiec Czerwony quarry is the second most important site of I. cottae tracks in the world after the early Permian Bromacker locality in Germany [21,22]. Biostratigraphical and radioisotopical data suggest an early Permian age for the Building Sandstone member of the Słupiec Formation [16,17,23].…”

Influence of Late Carboniferous–Early Permian climate change on the sedimentary evolution – a case study of the lacustrine Lower Anthracosia Shales (Intra-Sudetic Basin, SW Poland)

“…We de scribe the pet ro log i cal and geo chem i cal re cord of the Penn syl va nian-Lower Perm ian of the Intra-Sudetic Ba sin, namely of the Lower Anthracosia Shales (LAS), in or der to constrain the in flu ence of cli ma tic fac tors on the sed i men tary sys -tem, while also tak ing the con tri bu tion of tec tonic and vol ca nic ac tiv ity into con sid er ation. The Anthracosia Shales have been pre vi ously de scribed as re gards their strati graphic, palynological and sedimentological fea tures, and their or ganic pe trogra phy (Dziedzic, 1959(Dziedzic, , 1961Don, 1961;Miecznik, 1989;Lorenc, 1993;Bossowski and Ihnatowicz, 1994;Mastalerz and Nehyba, 1997;Nowak, 1998Nowak, , 2003Nowak, , 2007Nowak et al, 2022;Kowalski and Furca, 2023).…”