Coal-bearing fluvial cycles of the late Paleozoic tropics, astronomical control on sediment supply constrained by high-precision radioisotopic ages, Upper Silesian Basin

0556448 - GFÚ 2023 RIV NL eng J - Journal Article
Opluštil, S. - Laurin, Jiří - Hýlová, L. - Jirásek, J. - Schmitz, D. - Sivek, M.
Coal-bearing fluvial cycles of the late Paleozoic tropics, astronomical control on sediment supply constrained by high-precision radioisotopic ages, Upper Silesian Basin.
Earth-Science Reviews. Roč. 228, May (2022), č. článku 103998. ISSN 0012-8252. E-ISSN 1872-6828
Institutional support: RVO:67985530
Keywords : late Paleozoic * fluvial cycles * cyclothems * cyclostratigraphy * CA-ID TIMS geochronology * biostratigraphy
OECD category: Geology
Impact factor: 12.1, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/abs/pii/S0012825222000824

The late Paleozoic sedimentary record is well known for its mixed marine-terrestrial coal-bearing sedimentary sequences, traditionally called cyclothems, and their hypothetical glacioeustatic sea-level control. In contrast, coeval sedimentary cycles deposited in continental, nonmarine settings have received comparatively little attention. These fluvial and fluvio-lacustrine cycles are common in many late Paleozoic basins across paleoclimatic belts ranging from the tropics to the higher latitudes. Several mechanisms explaining the origins of these sequences have been suggested, including autogenic processes and tectonically driven allocycles. However, progress in understanding the climatic signal recorded in paleosols together with cyclostratigraphic analysis indicate that these terrestrial cycles record climate-driven upstream changes in sediment supply, possibly linked to astronomical (Milankovitch) forcing. We evaluate this hypothesis by reviewing the existing models for repetitive fluvial facies and the lateral continuity of coal-bearing fluvial cycles in the Upper Silesian Basin (similar to 3 degrees S paleolatitude). In this basin, mixed terrestrial-marine short eccentricity-driven coal-bearing cyclothems of Serpukhovian age are replaced in the Early Pennsylvanian by coal-bearing fluvial allocycles of the Saddle and Lower Such ' a Members (Bashkirian). Facies and cyclic pattern analyses suggest that the terrestrial cycles record alternation of contrasting fluvial styles: a low sinuosity avulsive/laterally migrating sand and gravel dominated braided river and fluvial systems with well-developed floodplains and narrow channels transporting minimal sediment load across widespread peat swamps. Tonsteins in coals indicate that peat swamps were broadly isochronous over a large area. Lateraly persistent coals and fluvial channels indicate clastic deposition not coeval with periods of active peat accretion in extensive and long-lasting swamps.
Permanent Link: http://hdl.handle.net/11104/0330665