Acta Geologica Polonica

Cenozoic tectonic evolution of the main lignite-rich grabens in Poland. Part 2. Tectonics versus autocompaction and compaction

2024-07-03T14:14:30+02:00

This paper is a continuation of the previous one (Widera, 2024. Acta Geologica Polonica, 74 (1), e2). A new, alternative interpretation of the tectonic development of two lignite-rich deposits in the Lubstów and Kleszczów grabens in central Poland is presented. The maximum thickness of lignite mined from both deposits is >86 and >250 m, respectively. These grabens were selected for detailed tectonic analysis because syn-depositional or post-depositional tectonic uplift is undeniably evident. The current study focuses on the distinction between tectonic subsidence/uplift and autocompactional subsidence, and on the timing of their occurrence. Such a research approach allows for the presentation of new conceptual models of Cenozoic tectonic evolution during the formation of the third, very thick, Ścinawa lignite seam (ŚLS-3) and the second Lusatian lignite seam (LLS-2). As a result, it is shown here that the magnitude of both the downward and upward tectonic movements are significantly smaller than previously thought. This new interpretation is also confirmed by the low rank of lignite coalification and the net calorific value of the ŚLS-3 and LLS-2.

Correlation of the Coniacian and Santonian stages of the Upper Cretaceous in the Anglo-Paris Basin

2024-07-05T12:52:42+02:00

The correlation of the Coniacian and Santonian chalks of the Anglo-Paris Basin is described on the basis of detailed lithological logs and extensive records of macrofossils and microcrinoids. In the almost complete absence of ammonites, inoceramid bivalves afford the highest resolution correlation of these stages in chalks, but their value here is limited by the absence of key genera and species, most notably in the Upper Coniacian and middle and Upper Santonian. Echinoids and other macrofossils (brachiopods, stalked crinoids, belemnites) have proved useful, but many are long-ranging or uncommon. Some marker beds, including flints and marl seams, provide useful correlations across the basin, but are locally absent. For the Upper Santonian, the stemless benthonic crinoids Uintacrinus and Marsupites provide high-resolution correlation, both within the basin and to other regions. The successions on the basin margins, in the far north of France (Nord, Pas de Calais) and the southwest (Touraine) are condensed and yield ammonites in association with important inoceramid species. The controls on sedimentation caused by sea-level changes are evaluated on a basinal and global scale, most especially for the Upper Santonian.

Spit bar deposits from the Upper Cretaceous (Cenomanian) transgressive sequence in NE Bohemia (Czechia)

2024-08-01T10:10:35+02:00

We propose a spit bar setting as the possible palaeoenvironment of the basal Late Cretaceous transgressive sequence in NW Bohemia. A new Cenomanian transgression model for the Bohemian Basin is also proposed. The uppermost Devět Křížů Sandstone, which has been conventionally referred to the Bohdašín Formation, probably represents the middle or lower upper Cenomanian (Upper Cretaceous), not the Triassic as previously supposed. We assume that this controversial unit was deposited before the main latest Cenomanian–early Turonian transgression. The spit bars were likely overgrown by vascular plants during their emergence in the late Cenomanian, and then inundated during the latest Cenomanian and early Turonian transgressive phases. The studied deposits had been intensively bioturbated, and the cf. Taenidium suite was recognized for the first time in them alongside the Thalassinoides assemblage (T. paradoxicus, T. suevicus, Thalassinoides isp., cf. Thalassinoides), which are characteristic of the Scoyenia and Glossifungites ichnofacies, respectively. The bioturbated, rhizolith-bearing horizon was presumably a paleosol.

On some Turonian and Coniacian ammonites from the Czech Republic

2024-08-01T10:33:33+02:00

Ammonites, chiefly from the Upper Turonian Prionocyclus germari Zone, the Lower Coniacian part of the Forresteria (Harleites) petrocoriensis Zone, and the Lower Coniacan Peroniceras (Peroniceras) tridorsatum Zone from the Czech Republic are figured and described, including classic material originally described by Fritsch (1872–1898) and Jahn (1892, 1896). In all, 25 species are recognised, including two, Pseudojacobites sp. and Muniericeras sp., that represent genera previously not known from the area.

Sub- and supra-moraine loesses in the Vistula catchment (Poland) with regard to the age and extent of the Scandinavian ice-sheets

2024-08-01T10:59:38+02:00

The study focuses on the geochronology and correlation between loesses and glacial tills in the Vistula catchment in Poland, in an area covered by all Scandinavian ice-sheets and characterized by thick loess successions. The basis for this correlation was a litostratigraphic analysis of selected loess sites in the uplands, which are well-documented in the literature, and the occurrences of loess and loess-like deposits under the cover of glacial deposits in the lowland part of the Vistula catchment, characterized by a much sparser documentation. The nomenclature of loess horizons follows Maruszczak (2001) and Kukla (1987), but sometimes is significantly
changed, according to modern Quaternary stratigraphical schemes. According to the analysis, accumulation of almost all loess horizons distinguished so far has been documented in the Pleistocene succession of the Vistula catchment: the oldest – lower (LNd), middle (LNs), and upper (LNg); older: lower (LSd), middle (LSs), and upper (LSg); and younger: lowest (LMn), lower (LMd), middle (LMs), and upper (LMg). In most cases loess accumulation took place in steppe-tundra conditions preceding the maximum ice-sheet development during the succeeding Scandinavian glaciations. For selected sites, the loess occurrence is presented in superposition
to glacial tills and interglacial deposits. The distinguished loesses and glacial tills are tied to the stratigraphic schemes of the Pleistocene in Poland (Marks et al. 2016, 2019) and correlated with Ukrainian loess horizons (Łanczont et al. 2019).

The serpulid tube worm Laqueoserpula reussi (Weinzettl, 1910) from the Upper Cretaceous of the Bohemian Cretaceous Basin - an alleged gastropod which has turned out to be a characteristic faunal element of marine nearshore high-energy environments

2024-08-01T11:17:11+02:00

The serpulid tube worm Laqueoserpula reussi (Weinzettl, 1910), originally introduced as a gastropod named Burtinella(?) reussi, is described from the Upper Cenomanian and Lower Turonian of the Bohemian Cretaceous Basin. It had usually been confused with other species and genera before 2008. Comparison with specimens from the type locality of the type species of the genus Laqueoserpula Lommerzheim, 1979 confirms the affiliation of the Bohemian species to this genus. The simple prismatic (SP) ultrastructure of the tube wall of L. reussi agrees with an assignment to the tribe Serpulini Rafinesque, 1815. In the Upper Cretaceous, representatives of Laqueoserpula are exclusively found in nearshore deposits, where they are accompanied by a high diverse marine invertebrate fauna. By its compact, large and robust tube forming a spiral and extremely thick tube wall, L. reussi was well-adapted to live in nearshore high energy environments, where its tube could be encrusted by bryozoans, brachiopods and oysters, and infested by hydroids and borers.

Application of palynomorphs and palynofacies in Early Cretaceous paleoenvironmental reconstruction; Shushan Basin, Egypt

2024-08-01T12:10:22+02:00

An integration of palynomorph and palynofacies data from the Shushan-1X well is used to infer the paleoenvironmental conditions of the Valanginian to Middle Cenomanian (Cretaceous) section of the western Shushan Basin, northern Egypt. The data obtained contribute significantly to the depositional history of the basin. The low diversity of dinoflagellate cyst assemblages, along with the dominance of land-derived spores and pollen, suggest restricted (marginal) marine environments, in contrast to their coeval representatives from the Tethyan Realm. Open marine (inner shelf) environments developed at a few horizons in the Dahab and Bahariya formations, partly contemporary with the global Aptian and Cenomanian eustatic cycles. These environments were relatively more offshore than those described in the eastern and southeastern parts of the basin. The study of total palynological organic matter (TPOM) has contributed largely to these established environmental settings. It has also allowed the recognition of redox (suboxic to anoxic) conditions and the impact of a large magnitude of terrigenous influence.

The maximum extent of the Odranian Glaciation (Saalian, MIS 6) in the South Podlasie Lowland (SE Poland) in the light of sites with lacustrine deposits of the Mazovian Interglacial

2024-08-01T12:18:45+02:00

Based on the analysis of the geological context and palynological studies performed on lake and bog sediments in the Southern Podlasie Lowland, a new concept of the maximum extent of the Odranian Glaciation (Saalian, MIS 6) is presented for the study area. It is depicted by the Siedlce-Łosice-Kornica zone of end moraines, which so far was considered as stadial-rank or as the Wartanian ice sheet limit. To the south of this zone, near Biała Podlaska and in the Łuków Plain, there occur numerous sites with fossil deposits of the Mazovian Interglacial (MIS 11c). Sites with new documentation, i.e., Wólka Domaszewska, Kolonia Bystrzycka, Przytulin, Hermanów, and Skrzynka are located about 30 km to the south and 6 km to the west of the Biała Podlaska area. Palynological analysis unequivocally indicates the presence of a vegetation succession characteristic of the Mazovian Interglacial. In all sites, deposits of the Mazovian Interglacial are covered by lacustrine sediments of the Liviecian Glaciation (Fuhne, MIS 11b-MIS 10) or mineral sediments of the Vistulian Glaciation (Weichselian, MIS 2) and the Holocene. The sediments infill paleolakes carved in glacial tills of the Sanian 2 Glaciation (MIS 12). The lake sediments of the Mazovian Interglacial and the overlying biogenic and mineral deposits occur in the analysed sites directly below the surface. They are never covered by glacial deposits, which suggests that the Odranian ice sheet did not cover the study area. The location of the lake and bog sites with their geological analysis allow for the precise depiction of the eastern limit of the Odranian ice sheet lobe, which in the study area correlates with the limit suggested in the late 19th century. The Odranian ice sheet did not cover Southern Podlasie.