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EN
The Frasnian carbonate-siliciclastic deposits of the Stipinai Formation exposed in two quarries at Petrašiūnai and Klovainiai (northern Lithuania) show considerable vertical facies changes. The lower part of this succession is dominated by argillaceous dolomitic facies with subordinate fine siliciclastic deposits. They display haloturbation and bioturbation structures, represent a hypersaline lagoonal environment, and record the beginning of the transgression. The middle part of the succession consists of secondary dolostones containing moulds of brachiopods, tetracorals, stromatoporoids and trace fossils of deposit feeders; these were deposited in a shallow subtidal marine environment and represent the deepest sedimentary environment of this succession. This was followed by a lagoonal environment (episodic hypersaline), represented by dolomudstones and marly dolomudstones. The upper part of the succession is built of bedded dolostones which document a shallowing trend. Intercalations of clays and palaeosol horizons record emergence events. Palynostratigraphic data tentatively indicate that the Stipinai Formation represents the Upper Frasnian. The succession can be interpreted as a record of the upper part of a T-R cycle (related to the semichatovae transgression) in the Main Devonian Field of the East European Platform. The Stipinai Formation is distributed across western and central Latvia and has a correlative in the Pomerania Basin (northern Poland).
PL
Złoże dolomitów Ujków Stary jest pozabilansowym fragmentem dawnego złoża rud cynku i ołowiu kopalni Bolesław. Opracowanie jego dokumentacji geologicznej z 2006 roku stworzyło nowe perspektywy pozyskania surowca skalnego ze skał dolomitycznych dolnego i środkowego wapienia muszlowego, występujących w serii złożowej. Skały te są wyraźnie zróżnicowane pod względem cech strukturalnych i teksturalnych oraz udziału składników mineralnych. W artykule przedstawiono charakterystykę tej zmienności na podstawie badań próbek skał pobranych z różnych części dwóch poziomów eksploatacyjnych złoża. Stwierdzono, że w złożu występują dolomity o strukturze mikrosparytowej i sparytowej (drobnokrystalicznej i średniokrystalicznej) oraz brekcje dolomityczne. Dowiedziono, że różnorodność petrograficzna skał, związana z ich genezą, ma istotny wpływ na zmienność ich podstawowych fizyczno-mechanicznych właściwości: gęstości objętościowej, nasiąkliwości i wytrzymałości na ściskanie. Ta zmienność petrograficzna skał decyduje także o niejednorodności jakościowej uzyskanych z nich kruszyw. Podstawą do wnioskowania w tym zakresie były wyniki badań odporności na ścieranie (wskaźnik mikro-Devala) i rozdrabnianie (wskaźnik Los Angeles) oraz ocena poziomu reaktywności alkalicznej kruszyw reprezentujących wybrane odmiany dolomitów oraz mieszaninę wszystkich wydzielonych odmian. Stwierdzono, że poszczególne partie kruszywa dolomitowego, pozyskiwane z różnych części złoża, mogą odpowiadać odmiennym kategoriom, określonym przez normy PN-EN. Wykazują one tym samym zróżnicowaną przydatność do stosowania ich między innymi w betonach, mieszankach bitumicznych stosowanych w powierzchniach przeznaczonych do ruchu oraz w niezwiązanych i związanych hydraulicznie materiałach używanych w obiektach budowlanych i budownictwie drogowym.
EN
The Ujków Stary deposit is an uneconomic fragment of the former zinc and lead mine in Bolesław. A geological report prepared in 2006 displays some new perspectives of the Lower-Middle Muschelkalk (Middle Triassic) dolostones. The rocks clearly differ considering their structures, textures and mineral composition. The author characterizes the rock variability based on the investigations of the samples collected from various exploitation levels of the Ujków Stary quarry. The rocks represent microsparitic and sparitic (fine- and medium-crystalline) dolostones, and dolostone breccias. The petrographical variability depends on the rock genesis and significantly affects the essential differences of the physical and mechanical properties of the dolostones, i.e., their bulk density, water absorption and compression strength. Therefore, the aggregates that are mined in Ujków Stary usually differ in their quality which results from the grindability resistance tests (micro-Deval index), fragmentation tests (Los Angeles index) and the alkaline reactivity assessment of the aggregates representing selected dolostone varieties and their components. Some dolostone aggregates obtained from various parts of the deposit correspond to various product categories determined according to PN-EN standards. For this reason, the applicability of the aggregates to be used, among others, to manufacturing concretes, bituminous road surface composites, and also set and unset hydraulic structural and road materials, may considerably vary.
EN
The paper is focused on multi-stage dolomitization process in the Lower-Middle Triassic succession of the High-Tatric series from the Western Tatra Mts. Lower and Middle Triassic bedded dolostones have several features indicating their early-diagenetic (synsedimentary) origin: preservation of sedimentary structures, fine-grained fraction (except redeposited deposits), relatively high concentration of siliciclastics, pseudomorphs after sulfates, lack of benthic fauna (except storm deposits). This can also be identified by presence of teepee structures and solution-collapse breccias. The sedimentological features and δ13C values may lead to conclusion that bedded dolostones were formed in the hypersaline environment, within supra- to interitidal zone. The part of bedded dolostones (mainly Early Triassic and latest Middle Triassic age) were formed during dilution of hipersaline waters by periodic fresh-water inputs. Positive correlation between δ13C and δ18O in dolomitized calcarenites suggests dolomitization with the influence of mixed meteoric and marine (hypersaline) waters. That dolomitization process took place during relatively early stage of burial diagenesis at marine regression times. The δ13C values of dolomitized calcilutites, as well as mosaic and saddle dolomitic cements suggest the dolomitization by solutions of marine origin. The lack of correlation between δ13C and δ18O indicates high temperature of these solutions. The values of δ18O indicate the temperature formation of dolomitic mosaic cements at 45-65°C. Calcilutites were dolomitized at 70-80°C, and saddle dolomite cements were formed in similar thermal conditions (70–85°C). Hydrothermal dolomitization is dated on Middle Triassic time.
EN
The Upper Olenekian and Middle Triassic shallow water carbonates from Tatra Mts. were hitherto described using old, descriptive nomenclature only. Moreover, some sedimentological features were also misinterpreted, for example, fenestral structures were described mostly as organic ones. Authors carried out genetic reinterpretation of these sediments and selected sedimentological structures, which allow to apply modern terminology for the mentioned carbonate rocks. Generally, dolomites with fenestral structures are interpreted as early diagenetic sabkha dolomites with pseudomorphs after sulfates (gipsum, anhydrite). Fenestral structures in dedolomites are also interpreted as evaporite pseudomorphs while those developed in mudstones are interpreted as pseudomorphs after celestite. Dolosparites, earlier described as "sugar dolomites", are actually dolomitized calcarenites (grainstones and packstones).
EN
The paper focuses on an interpretation of sedimentary and early diagenetic environment in the carbonate-dominated uppermost Ladinian-Norian succession from the Tatricum domain of the Tatra Mountains as well as its controlling factors. Limestones with cherts are the product of pedogenic processes, formed during long-term exposures of carbonate substrate. Chalcedony cherts were formed during relatively early diagenesis of pedogenic limestones. Dolostones and dolomitic mudstones were deposited in a kind of salt marshes. Pseudomorphs after sulfates and absence of benthic fauna indicate increased salinity and intensive evaporation. Additionally, low TOC concentration suggests a low productivity in the basin. On the contrary, stable isotope signals indicate that the sedimentary environment was strongly affected by meteoric water. Moreover, 18O and concentration of Sr suggest that dolostones were formed under the influence of both marine and meteoric waters. Dolomitic mudstones could be deposited in a salt-marsh environment fed by distal sheet floods. Components of palynological material and organic compounds in black dolomitic mudstones indicate the terrestrial origin of organic matter. Dolomitic regoliths were formed as the result of subaerial exposure and karstification of dolostones. Coarse-grained siliciclastics and variegated mudstone are interpreted, respectively, as a fluvial channel and flood plain facies of ephemeric fluvial environment. Sedimentary environment of the Keuper sediments was controlled by two main factors: synsedimentary tectonic movements and climate changes. In the latest Ladinian, the Middle Triassic carbonate platform was emerged, what resulted in the development of palaeosols. Block tectonic movements affected the Tatricum Basin in Keuper time. Horsts were emerged, whereas troughs were filled with fluvial or salt marsh sediments. Intensive tectonic movements are suggested by seismic-generated slumps and abrupt facies changes. More intensive chemical weathering and intensive contribution of pure siliciclastics suggest climate pluvialization in late Ladinian-early Carnian time. On the contrary, domination of physical weathering indicates the aridization of climate in late Carnian?-Norian time. The upper Carnian?-Norian succession was formed in hot and semi-arid climate conditions. Long-term climate changes was masked by short-term climate fluctuations. Geochemical indicators suggest that dolostones represent more humid periods, whereas dolomitic mudstones relatively dry periods.
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