caa a22 4500 606149422 CHVBK 20210128100534.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00531-015-1169-z doi (NATIONALLICENCE)springer-10.1007/s00531-015-1169-z Thermal history of the Sabero Coalfield (Southern Cantabrian Zone, NW Spain) as revealed by apatite fission track analyses from tonstein horizons: implications for timing of coalification [Elektronische Daten] [Dariusz Botor, Aneta Anczkiewicz] Apatite fission track (AFT) central ages from Carboniferous (Stephanian) tonsteins of the Sabero Coalfield, NW Spain, range from 140.8±7.5 to 65.8±8.1Ma (Cretaceous), with mean c-axis projected track length values ranging from 12.5 to 13.4μm. Mean random vitrinite reflectance (R r) of these samples ranges from 0.91 to 1.20%, which can be translated into maximum palaeotemperatures of ca. 130 to 180°C. All analysed samples experienced substantial post-depositional annealing. The considerably younger AFT ages compared to the depositional ages of the samples and R r data indicate the certainty of the occurrence of at least one heating event after the deposition of strata. The unimodal track length distributions, the relatively short mean track length, and the rather low standard deviation (SD) (1.0-1.6μm) indicate a relatively simple thermal history that could be related to the post-Late Variscan heating event followed by prolonged residence in the apatite partial annealing zone (APAZ). Geological data combined with thermal models of AFT data indicate that Stephanian strata reached the maximum palaeotemperatures in the Permian period, which was therefore the major time of the coalification processes. The Permian magmatic activity was responsible for a high heat flow, which, with the added effect of sedimentary burial, could account for the resetting of the AFT system. It appears that the fault-related hydrothermal activity could have redistributed heat in areas of significant subsidence. Cooling occurred in the Triassic-Cretaceous times after a high heat flow Permian regime. A post-Permian maturation of the Stephanian organic matter is not very likely, since there is no evidence of a high Mesozoic burial that was sufficient to cause a significant increase in the palaeotemperatures. Finally, exhumation and associated erosion rates may possibly have been faster in the Tertiary, causing the present exposure of the studied rocks. The Author(s), 2015 Sabero Coalfield nationallicence Cantabrian Zone nationallicence Apatite fission track analyses nationallicence Vitrinite reflectance nationallicence Thermal history nationallicence Pull-apart basin nationallicence Botor Dariusz Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, al. Mickiewicza 30, 30-059, Kraków, Poland aut Anczkiewicz Aneta Institute of Geological Sciences PAS, Senacka 1, 31-002, Kraków, Poland aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/7(2015-10-01), 1779-1793 1437-3254 104:7<1779 2015 104 531 https://doi.org/10.1007/s00531-015-1169-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-015-1169-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Botor Dariusz Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, al. Mickiewicza 30, 30-059, Kraków, Poland aut NATIONALLICENCE 700 1- Anczkiewicz Aneta Institute of Geological Sciences PAS, Senacka 1, 31-002, Kraków, Poland aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/7(2015-10-01), 1779-1793 1437-3254 104:7<1779 2015 104 531