The tectonic Wolsztyn-Pogorzela palaeo-High (WPH) is the south-eastern termination of the Brandenburg-Wolsztyn High (western Poland), which during Late Permian times was an intra-basin ridge surrounded by Upper Rotliegend sedimentary basins within the Southern Permian Basin. The geological history and structural framework of the WPH are complex. The High belongs to the Variscan Externides, consisting at present of strongly folded, faulted and eroded Viséan to Namurian flysch deposits capped by a thick cover of Upper Carboniferous-Lower Permian volcanic rocks. This sedimentary-volcanic complex was strongly fragmented and vertically differentiated by tectonic movements and subsequently eroded, resulting in the deposition of coarse clastics surrounding uplifted tectonic blocks. During late Rotliegend time, arid climatic conditions significantly influenced occurrences of specific facies assemblages: alluvial, fluvial, aeolian and playa. Sedimentological study helped to recognize the interplay of tectonic and palaeoclimatic factors and to understand the phenomenon of aeolian sandstones interbedded with coarse deposits of alluvial cones close to fault scarps.Subsequent tectonic and possible thermal subsidence of the studied area was synchronous with inundation by the Zechstein Sea. The rapid inundation process allowed for the preservation of an almost perfectly protected Uppermost Rotliegend landscape. Based on 3D seismic data from the base Zechstein reflector, a reconstruction of Rotliegend palaeogeomorphology was carried out, which shows examples of tectonic rejuvenation of particular tectonic blocks within the WPH area before inundation by the Zechstein Sea.The inundation led to the deposition of the marine Kupferschiefer Shale followed by the Zechstein Limestone. In the deeper parts of the basin the latter is developed in thin basinal facies: in shallow parts (e.g. uplifted tectonic blocks forming in some cases islands), carbonate buildups were formed. The remarkable thickness of those buildups (bryozoan reefs) is interpreted as due to stable tectonic subsidence together with a rise of sea level. A detailed study of carbonate buildups has showed that their internal structure reflects changes in shallow marine environments and even emersion events, caused by sea-level oscillations and tectonic movements of the reef substrate.
A tourmaline depleted in Si has been found in the cement of Upper Rotliegend aeolian sandstone overlaying Lower Rotliegend volcanic rock in the 'Ługi-1' prospecting borehole near Jarocin in the Fore-Sudetic Monocline, south-western Poland. Tourmaline, representing Mg-bearing foitite, crystallized around quartz grains in the form of radial aggregates of tiny crystals, reaching only 1-2 μm in diameter. Due to the very small size of the tourmaline crystals and the presence of significant contents of transitional metals in the crystal lattice, only direct determination of B 2 O 3 in nm-sized spots enables evaluation of [4] Al and [4] B. Compositions of the tourmaline in successive analytical spots show that Si deficiency is supplemented both by [4] Al (0.00 to 0.48 Al apfu) as well as by [4] B (0.00 to 0.83 B apfu) at varying proportions. The origin of the mineral was related to diagenesis of evaporate sediments inducing reactions of quartz and clay minerals as primary components in the tourmaline-bearing sandstone with Ca saturated pore brines rich in Cl -and (BO 3 ) 3-.
A., 2016. Sand sheets in ter ac tion with ae olian dune, al lu vial and mar ginal playa beds in Late Permian Up per Rotliegend set ting (west ern part of the Poznañ Ba sin, Po land). Geo log i cal Quar terly, 60 (4): 771-800, doi: 10.7306/gq.1336The Up per Rotliegend de pos its of the west ern part of the Poznañ Ba sin, Po land, rep re sent three main sed i men tary en vi ronments: ae olian desert (dunes and sand sheets), al lu vial plain (al lu vial cov ers with wadi de pos its) and mar ginal playa. In arid pe ri ods, dunes prograded into ar eas dom i nated by al lu vial sed i men ta tion. Dur ing wet pe ri ods, al lu vial de pos its eroded the ae olian de pos its and prograded onto dune fields. Playa sed i ments were de pos ited among ae olian or al lu vial sed i ments during pe ri odic ex pan sions of the playa. These aeolian, allu vial and playa de pos its are ar ranged in depositional se quences. Bound aries be tween se quences are marked by rapid changes in depositional fa cies; and by ero sional bound ing sur faces. Max i mum Wet ting Sur faces have been dis tin guished within some parts of the depositional se quences, which en able regional cor re la tions. The sec tions stud ied are com posed of thick se quences of sand and sand-gravel sheets. The sand sheets rep re sent pe ri ods of strati graphic con den sa tion. Sys tems of sand sheets are typ i cal of mar ginal ar eas of ergs. We dis tin guish nine depositional com plexes (units) num bered 1-9 from base to top, re spec tively. These sub di vi sions are based on the in ter pre ta tion of the sedimentological re cord in palaeoclimatic terms, and in terms of ma jor ero sional bound aries, which are prob a bly of re gional ex tent. In the ae olian de pos its, ma jor bound aries are as so ci ated with de fla tion sur faces related to the sta bi li za tion of ground wa ter lev els. In the mar ginal playa de pos its, the most im por tant bound aries are cor re lated to transgressive sur faces that de vel oped dur ing playa ex pan sion. Time gaps rep re sented by the bound aries and the scale of ero sion be low them, are dif fi cult to es ti mate. The depositional sys tem of the Up per Rotliegend was dom i nated by sand and sand-gravel sheets, and is ei ther a unique fea ture in the en tire South ern Perm ian Ba sin or, as we as sume, sand sheets oc cur more com monly in the Rotliegend than has been pre vi ously thought.
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