Thermal history of the East European Platform margin in Poland based on apatite and zircon low-temperature thermochronology

Abstract

Abstract. The Phanerozoic tectonothermal evolution of the SW slope of the East European Platform (EEP) in Poland is reconstructed by means of thermal maturity, low-temperature thermochronometry, and thermal modelling. We provide a set of new thermochronometric data and integrate stratigraphic and thermal maturity information to constrain the burial and thermal history of sediments. Apatite fission track (AFT) analysis and zircon (U-Th)/He (ZHe) thermochronology have been carried out on samples of sandstones, bentonites, diabase, and crystalline basement rocks collected from 17 boreholes located in central and NE Poland. They penetrated sedimentary cover of the EEP subdivided from the north to south into the Baltic, Podlasie, and Lublin basins. The average ZHe ages from Proterozoic basement rocks as well as Ordovician to Silurian bentonites and Cambrian to lower Carboniferous sandstones range from 848 ± 81 to 255 ± 22 Ma with a single early Permian age of 288 Ma, corresponding to cooling after a thermal event. The remaining ZHe ages represent partial reset or source ages. The AFT ages of samples are dispersed in the range of 235.8 ± 17.3 Ma (Middle Triassic) to 42.1 ± 11.1 Ma (Paleogene) providing a record of Mesozoic and Cenozoic cooling. The highest frequency of the AFT ages is in the Jurassic and Early Cretaceous prior to Alpine basin inversion. Thermal maturity results are consistent with the SW-ward increase of the Paleozoic and Mesozoic sediments thickness. An important break in a thermal maturity profile exists across the base Permian–Mesozoic unconformity. Thermal modelling showed that significant heating of Ediacaran to Carboniferous sedimentary successions occurred before the Permian with maximum paleotemperatures in the earliest and latest Carboniferous for Baltic–Podlasie and Lublin basins, respectively. The results obtained suggest an important role of early Carboniferous uplift and exhumation at the SW margin of the EEP. The SW slope of the latter was afterward overridden in the Lublin Basin by the Variscan orogenic wedge. Its tectonic loading interrupted Carboniferous uplift and caused resumption of sedimentation in the late Viséan. Consequently, a thermal history of the Lublin Basin is different from that in the Podlasie and Baltic basins but similar to other sections of the Variscan foreland, characterized by maximum burial at the end of Carboniferous. The Mesozoic thermal history was characterized by gradual cooling from peak temperatures at the transition from Triassic to Jurassic due to decreasing heat flow. Burial caused maximum paleotemperatures in the SW part of the study area, where the EEP was covered by an extensive sedimentary pile. However, further NE, due to low temperatures caused by shallow burial, the impact of fluids can be detected by vitrinite reflectance, illite/smectite, and thermochronological data. Our new results emphasize the importance of using multiple low-temperature thermochronometers and thermal modelling in connection with thermal maturity analysis to elucidate the near-surface evolution of platform margins.

Hydrocarbon generation modelling in the Permian and Triassic strata of the Polish Basin: implications for hydrocarbon potential assessment

“…lower heat flow) in the Late Cre ta ceous zone along the MPT were ob tained from thermochronological ap a tite fis sion-track data (Poprawa and Andriessen, 2006). In the area of EEC east of the TTZ, a re cently ac com plished thermochronological study of Botor et al (2021) sup ple mented by earlier work of Kowalska et al (2019) based on K-Ar dat ing and clay min er als and pro duced a more re li able ther mal his tory of this area. The Me so zoic ther mal his tory of the SW slope of the EEC area was char ac ter ised by grad ual cool ing from peak temper a tures (>120°C) at the tran si tion from the Tri as sic to Ju rassic due to de creas ing heat flow (Botor et al, 2021).…”

Post-Caledonian tectonic evolution of the Precambrian and Palaeozoic Platforms boundary zone offshore Poland based on the new and vintage multi-channel reflection seismic data

“…A recent apatite and zircon low-temperature thermochronology study postulates an important early Carboniferous uplift in the area of the Baltic Basin, NE of the CDF and Koszalin Fault (Botor et al, 2021). It remains uncertain from the seismic profiles presented whether this uplift was localised along the pre-existing Devonian faults or had a character of long wavelength doming.…”

First Evidence of the Post-Variscan Magmatic Pulse on the Western Edge of East European Craton: U-Pb Geochronology and Geochemistry of the Dolerite in the Lublin Podlasie Basin, Eastern Poland

“…A paleothermal investigation of the platform sediments performed recently, using multiple low-temperature thermochronometer methodologies e.g., apatite fission-track (AFT) and zircon (U-Th)/He (ZHe) and a K-Ar analysis of the clay fractions [78][79][80], allows for the identification of a few thermal events, which were related to the area of cratonic foreland of its neighboring orogenic systems. K-Ar dating of the clays from volcanogenic rocks (E Poland and W Belarus) documents [78] a thermal activity event coinciding with the events of the Caledonian orogeny (dated at 417-447 Ma).…”

“…was identified more to the south, close to Volyn area. Moreover, thermal modeling [80] showed that significant heating of the Ediacaran and Carboniferous sedimentary successions occurred before the Permian, with maximum paleotemperatures occurring in the earliest and latest periods of the Carboniferous for Baltic-Podlasie and Lublin Basins, respectively [80].…”

“…Such evidence of various magmatic and tectonic activities (regional uplift) jointly reflect the thermal perturbation of the lithosphere. The elevated Permian heat flow was probably a consequence of Early Permian continental rifting [80].…”