The characteristics of spatial distribution of silver minerals and Agin ore minerals within the Lower Zechstein formations at the contact zone between reduced rocks and the Rote Fäule oxidized rocks are shown. All presented outcomes are on based on rock material taken from mining profiles and some archival boreholes in the Radwanice-Gaworzyce deposit area. These studies were used microscopic observations in reflected light and by microprobe analyses using the CAMECASX-100. In all analyzed profiles, oxidized rocks (enriched in hematite) were found, which occur at various levels of the Kupferschiefer series beneath the reduced zone enriched in ore minerals. Silver in the reduced zone occurs in the form of its own minerals, such as: native silver, stromeyerite, mckinstryite, jalpaite, naumannite, silver amalgams. Futhermore, silver is present as Cu and Fe isomorphic substitutions in the crystal lattice of copper sulfides of the Cu-S and Cu-Fe-S groups and in As and Sb sulfosalt. In the oxidized zone, silver occurs as electrum, silver amalgams and substitutions in remnant copper sulfides. A decrease in the concentration of silverin ore minerals and in the content of silver minerals towards the top of the mineralized interval is characteristic. The concentration of silver (both in the form of its own minerals and as isomorphic substitutions in ores) is impoverished in the zone where the oxidation front crosses the Kupferschiefer shale than in the case when the stabilization of the redox front is at the border boundary of the Weissliegend sandstone with and the Kupferschiefer shale. The spatial distribution of silverin the Lower Zechstein formations at the contact zone between the reduced and oxidized rocks is the result of the evolution of ore mineralization, caused by the flows of mineralizing solutions, as evidenced by the depletion of the oxidized zone in silver, and its enrichment in the adjacent reduced rocks.
For a century - since the initiative of a group of parliament members to constitute the Polish Geological Institute (PGI) was supported by the Polish Parliament on May 30, 1919 - the PGI has success fully fulfilled all basic responsibilities and commitments that are conventionally assigned to national geological surveys. Like in the past, in modern geological surveys the research is of great importance and it is clear that they cannot exist without science, the same applies to the PGI. The scientific knowledge achieved during the implementation of geological survey tasks is important for the society and the country's development.
The paper presents the latest state of knowledge on the vertical and lateral ranges and characteristics of prospective zones (PZ) within the Lower Paleozoic unconventional hydrocarbon systems in the Baltic-Podlasie-Lublin Basin (Poland). The PZ were identified within the prospective formations based on rigorously determined criteria with the application of stratigraphic, sedimentological, mineralogical, petrographic, geochemical, petrophysical, and geomechanical studies, and interpretations of borehole logs. Archival geological data and information acquired from boreholes drilled recently in concession areas have also been applied in the interpretations. Following these criteria, four prospective zones have been distinguished. The deposits encompass partly or almost completely the Piaśnica, Sasino, and Jantar formations and the lower part of the Pelplin Formation. The characteristic feature of the Lower Paleozoic deposits at the East European Craton (EEC) margin in Poland is the diachronous appearance of the Sasino and Jantar black shale formations from west to east. The Baltic area is most prospective for the occurrence of unconventional hydrocarbon reservoirs in shale formations, specifically the Łeba Elevation, where all 4 prospective zones have been distinguished. The occurrence of liquid and gaseous hydrocarbons is expected in all zones. Due to the very high TOC content and geochemical characteristics, the Piaśnica Formation within PZ1 is the main petroleum source rock in the Polish part of the Baltic Basin. PZ2 (partly corresponding to the Sasino Formation) present in a large part of the Baltic Basin, is the next important prospective unit, despite not being uniform. PZ3 within the Jantar Formation was distinguished only on a limited area of the Łeba Elevation. Due to the low content of organic matter, the Lublin area is characterized by the lowest hydrocarbon potential. However, low values of that parameter are compensated by a greater thickness and lateral range of PZ4, partly corresponding to the Pelplin Formation. Comparison with other areas within the Lower Paleozoic Baltic Basin reveals the occurrence of shale deposits that may constitute a potential source of hydrocarbons, and that demonstrate diachronism. Towards the east and south-east, ever younger deposits possess the potential for hydrocarbon accumulations. In Poland, in the western part of EEC, these are: the Furongian and the Lower Tremadocian Piaśnica Formation, the Sandbian and Katian Sasino Formation and the Lower/Middle Llandovery (Rhuddanian and Aeronian) Jantar Formation. In the central part of the Baltic Basin (Lithuania), these are the Upper Ordovician and Aeronian shale successions. In the southeastern part of the basin (Ukraine), the Ludlow strata are considered to be the most promising in terms of the potential unconventional hydrocarbons accumulations.
The characteristic of ore mineralization in the immediate vicinity of fault zones in the Lower Zechstein deposits is shown. All presented outcomes are on the basis of rock material taken from mining profiles in the Radwanice-Gaworzyce deposit area. During conducted studies ore minerals and oxide minerals were identified under optical microscope in reflected light and photographic documentation of the examined samples was undertaken. In addition, microprobe examination was carried out for selected samples from the studied profiles along with calculations of the chemical composition of individual ore minerals. In all analyzed profiles, Rote Fäule oxidized zone (enriched with hematite) was found, which occurs at various levels of the Kupferschiefer series and the reduced zone (enriched with ore minerals) over the oxidized series. The redox front cuts across the boundaries oflithostratigraphic units, moving from the Weis- liegend to the higher parts of the Zechstein Limestone. The primary ore mineralization in the examined profiles is the chalcocite-digenite association with subordinate bornite and covelitte recorded in the reduced series. Furthermore, the secondary sulphide mineralization in the direct vicinity of tectonic deformation and faults superimposed on primary ore mineralization and hematite enrichments is observed and it is represented by chalcopyrite, bornite, tennantite, tetrahedrite and pyrite, both within reduced and oxidized zones.
Analiza obecnego występowania i zróżnicowania miąższości utworów ewaporatowych (siarczanowych i chlorkowych) górnego permu (cechsztyn) na obszarze centralnej części monokliny przedsudeckiej, bazująca na danych z 635 archiwalnych otworów wiertniczych, umożliwiła przedstawienie obrazu przypuszczalnej paleogeografii basenów siarczanowych i chlorkowych w przypadku niektórych ewaporatowych wydzieleń litostratygraficznych kolejnych czterech cyklotemów. Utwory siarczanowe i chlorkowe cyklotemów PZ1 i PZ3 oraz siarczany cyklotemu PZ2 (anhydryt podstawowy [A2]) powstały w zbiornikach o wyraźnie zróżnicowanej batymetrii, ze strefami płytszymi (bariera i płycizny) i głębszymi (baseny). Akumulacja tych osadów następowała według schematu występującego w basenie typu „wypełnieniowego”, w którym na etapie depozycji soli chlorki wypełniają głównie obniżenia dna wcześniejszego zróżnicowanego batymetrycznie zbiornika siarczanowego, zaakcentowane różnym tempem osadzania siarczanów (szybszym na płycinach i wolniejszym w basenach). Lokalne występowanie pozostałych ewaporatów cyklotemów PZ2 i PZ4 nie pozwala otworzyć paleogeografii ich zbiorników depozycji. Omówiono też wykształcenie wydzieleń ewaporatowych, wykorzystując dane z terenów sąsiadujących z obszarem badań w sytuacji braku miejscowego materiału rdzeniowego.Tektonika dysjunktywna (sieci uskoków i dwa rowy tektoniczne) w różnym stopniu przemodelowała pierwotne rozmieszczenie ewaporatów i spowodowała ich lokalny wzrost miąższości w strefach przyuskokowych.
EN
Analysis of recent extension and thickness of Upper Permian (Zechstein) evaporites (sulphates and chlorides) in the area of central Fore-Sudetic Monocline, based on data from 635 archive boreholes, enabled to reconstruct the possible palaeographic images of both sulphate and chloride basins, represented some evaporitic lithostratigraphic units of four Zechstein cyclothemes. Sulphates and chlorides of PZ1 and PZ3 cyclothemes as well as sulphates of PZ2 cyclotheme (Basal Anhydrite [A2] unit) have deposited in the basins with distinctly varied bathymetry, where existed the shallow (barrier and shoals) and the deeper (basins) parts. Their accumulation realized the depositional scheme of the „infill” type of evaporitic basin, after which dominant infill by chlorides took place in the deeps of former sulphate basin with differentiated bathymetry accentuated by other accumulate rate of sulphates (a higher on bottom shoals and slower in the deeps). Local occurrence of other evaporate units of PZ2 and PZ4 cyclothemes eliminated creation of similar palaeogeographic images for their depositional basins. Commented evaporite units were characterized by data representative for their age equivalents drilled in the nearest areas because of extremely rare core data form the study area. Disjunctive tectonics (fault systems and two tectonic grabens) modified in a different rate the primary extent of studied evaporites as well as it was responsible for their local thickness increase in the near-fault zones.
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