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EN
The beginning of exploitation of Lower Triassic (Röt, Olenekian) sandstones in Doły Biskupie dates back to the 17th century. The village is situated 12 km west of Ostrowiec Świętokrzyski, in the Świślina Valley, in the north-eastern part of the Holy Cross Mountains. In addition to sandstones, a wide spectrum of other rocks types were excavated in the adjacent areas: Lower Devonian (Emsian) sandstones in Godów, Middle Devonian (Efelian) dolomites in the Doły Opacie quarry and Lower Triassic (Middle Buntsandstein, Olenekian) sandstonesin Wióry. The last quarry at Doły Opacie was closed in 1984. The Doły Opacie and Doły Biskupie quarries currently provide a number of inanimate nature monuments.
EN
The beginning of exploitation of the Lower Devonian sandstones on Barcza Hill, located in the Klonów Range in the central part of the Holy Cross Mountains, dates back to the first decade of the last century. Sandstones of the lower Emsian Barcza Beds, known in older literature as “placoderm sandstones” were mined here. By the time of World War II, there were seven mines that produced mainly paving stones and crushed stone. Three of them resumed work after the war: “Kopalnia Nowa”, “Byk” and “Przy Pomniku”. Unfavourable deposit conditions and competition of the neighbouring mining plants "Bukowa Góra” and "Wiśniówka” led to the abandonment of mining on Barcza Hill in the late 1950s. In 1984, the “Barcza” nature reserve was created, which included the two largest quarries: "Kopalnia Nowa”and "Byk”.
EN
Majority of ca. 90 sites ofsandstone crag groups and individual crags, occurring in the Świętokrzyskie (Holy Cross) Mts. region, represent the following crag-forming lithostratigraphic units: Cambrian Wiśniówka Formation, Devonian Barcza Fm and Zagórze Fm, Triassic Zagnańsk Fm and Krynki Beds, as well as Jurassic Skloby Fm and Ostrowiec Fm. Specific features of these rocks are the occurrence of sandstone series, up to 20 m thick, above more plastic, clayey or heterolithic series, high-energy depositional environments, and siliceous composition. The crag-forming sandstones differ in the amount of siliceous cement: from strongly cemented Paleozoic quartzitic sandstones to porous Mesozoic sandstones with poor cement, which determines diverse mechanical properties. Strongly cemented Paleozoic rocks display high rock strength and abrasion resistance, while porous and theoretically friable Mesozoic sandstones are characterised by high grain packing due to compaction. Regarding the principal role of gravitational disinte¬gration of rock massifs under the periglacial conditions in the Pleistocene, other factors constraining the crag formation and shaping are the tectonic situation of rocks (orientation of strata and joints), adequate joint spacing, and bed thickness. The interrelations between lithological and structural features of crag-forming sandstones and tectonics, conditioning erosion and weathering rates are specific for particular types of these sandstones.
EN
In the Polish part of the Carpathian Foredeep, an intensification of gas exploration and exploitation from Miocene strata took place in the middle of the twentieth century. In spite of a good degree of geological and reservoir recognition, the area of the Carpathian Foredeep is still considered to be prospective for the discovery of new gas reservoirs. Here we analyse statistically selected reservoir parameters of Miocene deposits, such as total porosity, effective permeability and reservoir water inflow. These parameters have been determined on the basis of interpretations of results of well logs and reservoir tests with tubular bed samplers (DST, Drill Stem Test). Analytical results in the form of regression and dependence of the logarithm of permeability as a function of porosity show a weak correlation. However, in the study area, the distribution of porosity values for Miocene strata is close to normal.
EN
The St. Elizabeth of Hungary Basilica is one of the most important and recognizable monuments of Wroclaw - the capital of Lower Silesia (SWpart of Poland). The origin of the church dates back to the beginning of the 13th century. The basilica received its present Gothic form in the 14th-15th centuries. At the foot of the church tower, overlooking the buildings of the nearby Market Square, there is a late-Gothic portal built in 1456. This is the oldest portal of the basilica. Adjacent to it, there are epitaphs of wealthy Wroclaw burghers. These monuments are the top-class works of Silesian stonemasonry and also an interesting example of the use of natural stone in constructing architectural details. From the portal and three epitaphs (devoted to the Krapps’family, Georg Althoff Scholz and Hans Schulz von Wolkovitz), atotal often samples of clastic rock were collected. These were subjected to detailed petrographic and mineralogical studies in order to determine the provenance of the stone material. The research confirmed that these architectural details were made of quartz sandstones. The probable source of this material was the Cretaceous joint sandstones from the North-Sudetic Basin (Conacian, upper joint sandstone - Rakowice type).
EN
An excavation dug out in the glacially transported rock masses at Golaszyn near Łuków (eastern Poland), revealed the presence of deposits unknown so far in this area. These are older than the only known so far here glacially transported clays containing concretions with splendidly preserved ammonites of late Callovian at Łapiguz brickyard of Łuków. The succession exposed consists of sands and sandstones of Middle Callovian age which rest on red-brownish clays. The latter may be compared with the Triassic - Buntsandstein deposits of the northwestern Lithuania, that is the home area of glacially transported rock masses, commonly occurring in eastern Poland in the Łuków area. The new geological discoveries markedly increase a set of attractions for the promotion of the Łuków region for the education and geotourism purposes.
PL
Zróżnicowane właściwości fizycznych oraz różnorodność kolorów i faktur skał osadowych, sprawiają, że znajdują one zastosowanie w rozmaitych dziedzinach budownictwa i gospodarki. W Polsce skały te wydobywane są na terenie niemalże całego kraju. W niniejszej pracy analizowano w sposób szczególny wapienie, dolomity i piaskowce występujące na obszarze województwa świętokrzyskiego i małopolskiego. Zestawiono ich parametry fizyczno-mechaniczne oraz cechy wizualne, a następnie dokonano porównania. Na podstawie otrzymanych wyników porównań przyporządkowano skałom sposoby ich wykorzystania.
EN
Diversified physical properties and diversity of colors and structures of sedimentary rocks make them applicable in various fields of construction and economy. In Poland, these rocks are mined in almost the entire country. In this work, the limestones, dolomites and sandstones occurring in the area of the Świętokrzyskie and Małopolskie voivodships were analyzed in a special way. Physico-mechanical parameters and visual characteristics of the studied rocks were compared. On the basis of the obtained results of comparisons, the ways of utilization were assigned to the relevant rocks.
EN
Information on Jurassic palynomorphs from the Greater Caucasus is potentially of great importance, but its availability to the international research community is severely limited. New palynological data for Toarcian deposits of the Western Caucasus are recorded in the present paper. Particularly, dinoflagellate cysts are described for the first time from the Bagovskaja Formation; palynomorphs are found in sandstone levels within this unit. The most representative assemblage includes pollen (with predominant bisaccate pollen), spores (Cyathidites being commonest), and dinoflagellate cysts amongst which the predominant taxon is Nannoceratopsis spiculata. The dinocyst assemblage implies a late Toarcian age for the upper part of the Bagovskaja Formation. On the basis of these new palynostratigraphical results, the range of the formation is extended; previously, only the lower part had been dated on ammonite evidence.
PL
Celem artykułu była charakterystyka petrofizyczna piaskowców poziomu karbonu w profilu odwiertu Paproć-29, zlokalizowanego w północnej części monokliny przedsudeckiej. Pomiary porozymetrii rtęciowej zostały przeprowadzone na 12 próbkach materiału rdzeniowego w celu oszacowania podstawowych parametrów petrofizycznych, obejmujących porowatość efektywną i dynamiczną dla gazu i ropy, gęstość szkieletową i objętościową, a także szeroko pojętą geometrię przestrzeni porowej. Otrzymane wyniki pozwoliły zaklasyfikować piaskowce karbońskie do skał o bardzo niskiej pojemności zbiornikowej oraz przypisać im porowy typ przestrzeni zbiornikowej. Ponadto wskazano interwał głębokościowy skał o relatywnie dobrych właściwościach petrofizycznych w kontekście występowania złóż gazu zamkniętego (tight gas).
EN
The purpose of the study is to determine the petrophysical characteristic of the Carboniferous sandstones in the Paproć-29 borehole section, located in the northern part of the Fore-Sudetic Monocline. Mercury Injection Capillary Pressure (MICP) measurements were conducted on 12 core samples in order to assess basic petrophysical parameters, including effective and dynamic porosities for oil and gas, bulk and skeletal densities and broadly comprehended pore space geometry. The data obtained from method used in this study have allowed to classify sandstones as poor hydrocarbon reservoir capacity rocks and define their pore space character as pore-fracture type. In addition, the rock interval of relatively good petrophysical properties in the context of the presence of tight gas deposits was indicated.
PL
Badaniom poddano przykładowe piaskowce, różniące się genezą i wykształceniem, w celu określenia wpływu mikrostruktur kierunkowych na ich właściwości. Dla pobranych prób przeprowadzono obserwacje petrograficzne oraz wykonano badania właściwości fizycznych i mechanicznych. Mikrostruktury kierunkowe objawiały się występowaniem w próbach wydłużonych ziaren ułożonych w preferowanych kierunkach, obecnością laminacji równoległej bądź przekątnej, związanej z wysortowaniem ziaren i laminarnym nagromadzeniem substancji spoiwa czy mikrospękań lub ich wtórnych wypełnień. Próbą ilościowej oceny wymienionych cech było określenie poza graficznymi parametrami uziarnienia, także wskaźnika kształtu ziaren kwarcu. Badania prędkości fal podłużnych i ścieralności na tarczy Boehmego przeprowadzone na zorientowanych sześciennych próbach wykazały istnienie anizotropii tych parametrów, co powiązano z obecnością struktur linijnych. Przedstawiono wartości współczynnika anizotropii także dla innych kierunkowo uwarunkowanych właściwości, przewidując zależność pomiędzy jego wielkością a zdolnością pękania i niszczenia skały wzdłuż preferowanych powierzchni.
EN
Sandstones of different genesis and development were studied with the aim of establishing an impact of directional microstructures on rock properties. The investigations included petrographical observations and physico-mechanical determinations. The microstructures were manifested in the presence of elongated grains arranged along preferred directions, in the parallel or diagonal lamination resulting from grain sorting and laminar accumulation of cement substances, and also in microfractures filled with secondary mineral substances. An attempt of quantitative estimation of these characteristics was achieved by calculation of the shape index of quartz grains, besides the graphic grain-size parameters. Measurements of the velocity of ultrasonic waves and abrasion resistance of the sandstones using Böhme tests conducted on oriented sandstone cubes have revealed an anisotropy of the rock properties, which has been attributed to the presence of linear structures of the sandstones. The values of the anisotropy coefficient have also been established for other, directionally controlled rock properties, predicting the dependence between this coefficient and the fracturing and damaging of sandstones along preferred surfaces.
PL
W artykule scharakteryzowano przypowierzchniową część warstw orzeskich w rejonie siodła głównego. W profilu litologicznym omawianego rejonu stwierdzono obecność iłowców przewarstwionych piaskowcami oraz występujące na powierzchni piaski. Wśród iłowców nawiercono warstwę węgla. Obserwacje terenowe z użyciem kamery, bezpośrednio w wykonanych otworach wiertniczych oraz badania laboratoryjne pobranych próbek skał wykazały znaczny stopień zwietrzenia utworów klastycznych. W obrębie warstw piaskowców w wyniku oddziaływania czynników wietrzenia tworzą się szczeliny oraz pustki skalne, którymi w głębsze partie górotworu swobodnie przesącza się woda opadowa. Piaskowce w składzie mineralnym zawierają przede wszystkim kwarc, któremu w mniejszych ilościach towarzyszą plagioklazy, łyszczyki, okruchy skalne i minerały ciężkie. Spoiwo piaskowców jest typu cement, ilasto-węglanowe. Występujące na powierzchni piaski stanowią ich zwietrzelinę, o czym świadczą podobne cechy teksturalne obu osadów. Iłowce bogate są w kaolinit i kwarc; w ich składzie stwierdzono również minerały z grupy smektytu. Charakteryzują się bardzo dużą nasiąkliwością, co prowadzi do ich pęcznienia i rozmywania. Stwierdzono, że zwietrzałe partie skał wykazują znacznie obniżoną wytrzymałość na ściskanie w stosunku do wartości przyjmowanych dla skał warstw orzeskich.
EN
The article presents the characterization of a near-surface part of Orzesze beds in the region of the main saddle. The lithological profile of the region in concern has been confirmed to contain claystones with interburdens of sandstones and sands occurring at the surface. Among the claystones, a coal bed was drilled into. Field observations with a video camera, direct observations made in the boreholes and laboratory studies of the obtained rock samples have indicated high levels of weathering of the clastic formations. The weathering processes within the sandstones form fissures and rock voids by means of which rainwater flows freely into the deeper parts of the rock mass. The mineral composition of the sandstones includes mostly quartz, accompanied by plagioclases, micas, breccias and heavy minerals in smaller amounts. The binding material is cement-type and clayey-carbonate. The sands occurring at the surface constitute their eluvium, which is evidenced by similar texture qualities of both the sediments. The claystones contain mostly kaolinite and quartz; in their composition minerals from smectite group were also found. They are characterized by very high absorbability, which leads to their swelling and washing out. It has been found that the weathered parts of rocks indicate significantly lowered compressive strength in comparison to the values assumed in case of the rocks of the Orzesze beds.
EN
Often analyses of depositional environments from sparse data result in poor interpretation, especially in multipartite depositional settings such as the Niger Delta. For instance, differentiating channel sandstones, heteroliths and mudstones within proximal environments from those of distal facies is difficult if interpretations rely solely on well log signatures. Therefore, in order to achieve an effective and efficient interpretation of the depositional conditions of a given unit, integrated tools must be applied such as matching core descriptions with wireline log signature. In the present paper cores of three wells from the Coastal Swamp depositional belt of the Niger Delta are examined in order to achieve full understanding of the depositional environments. The well sections comprise cross-bedded sandstones, heteroliths (coastal and lower shoreface) and mudstones that were laid down in wave, river and tidal processes. Interpretations were made from each data set comprising gamma ray logs, described sedimentological cores showing sedimentary features and ichnological characteristics; these were integrated to define the depositional settings. Some portions from one of the well sections reveal a blocky gamma ray well log signature instead of a coarsening-upward trend that characterises a shoreface setting while in other wells the signatures for heteroliths at some sections are bell blocky in shaped rather than serrated. Besides, heteroliths and mudstones within the proximal facies and those of distal facies were difficult to distinguish solely on well log signatures. However, interpretation based on sedimentology and ichnology of cores from these facies was used to correct these inconsistencies. It follows that depositional environment interpretation (especially in multifarious depositional environments such as the Niger Delta) should ideally be made together with other raw data for accuracy and those based solely on well log signatures should be treated with caution.
EN
Natural gas in the Polish Rotliegend Basin occurs in porous and permeable aeolian sandstones, and traps are mostly structural. Lithological traps are rare and occur on the northern slope of the Wolsztyn Ridge where fluvial and aeolian sandstones overlap with alluvial facies. Both fluvial and aeolian sandstones are reservoir rocks in this area. The X-ray micro computed tomography (MCT) results and microscopic observations indicate that the sandstones in lithologic traps on the northern slope of the Wolsztyn Ridge form highly compartmentalized vertical reservoir rocks composed of four types of sandstones. The profiles are dominated by very low-porosity fluvial sandstones (F2), and low-porosity aeolian and fluvial sandstones (A2, F1). The A1 type of sandstones with high porosity (10%) occurs only in some sections of the profiles. The most important diagenetic processes that reduced porosity were compaction and cementation by carbonate cements. All studied sandstones were subjected to the same diagenetic processes. However, each of the processes ran with varying intensity in different types of sandstones. Detailed analyses of pore distribution by MCT methods with respect to primary depositional or lithofacies effects, and secondary diagenetic effects, help to understand the 3D geometry of pores and pore shape-size distributions. The results can be used in the studies of other sandstones with a different origin and age.
EN
Natural humidity of rocks in the Upper Silesian Coal Basin results from the influence of mining activities and dewatering the rock mass. The state of humidity which best approximates laboratory rock tests to the conditions in the exploited rock mass is the capillary saturation state. Deformation properties of sandstones (Young’s modulus, post-peak failure modulus, critical strain, residual strain) were determined for samples of slenderness ratio of 1 and 2, which were loaded in a servo-controlled testing machine. In the samples of sandstones of different slenderness ratio, values of Young’s modulus decreased for the samples in dry-air condition and capillary saturation state. In the samples of rocks of different slenderness ratio, tested in the same state of humidity, an increase in the value of Young’s modulus was observed. The increase depends on grain size. Post-peak failure modulus of sandstones shows similar trends of changes depending on slenderness ratio, state of humidity of the samples and their grain size. In the conditions when the samples of sandstones of slenderness ratio of 1, were tested in two states of humidity, values of critical strain decreased by a few per cent. For the samples of greater slenderness ratio, which also were tested in two states of humidity there was an increase in the value of critical strain and in humidity. For the samples of slenderness ratio of 1 and 2 tested in dry-air condition and in capillary saturation state there was a decrease in the value of critical strain by a few tens percent. The trends of changes in values of residual strain are the same as of critical strain. Based on the conducted tests it was shown that humidity and slenderness ratio of the sandstone samples influence differently their deformability. Humidity has a greater influence on the value of Young’s modulus than slenderness ratio of the tested samples. For critical strain and residual strain it was demonstrated that slenderness ratio of the samples has a greater influence than humidity. Moreover, a greater influence of the value of residual strain, in comparison with the values of critical strain, was observed for sandstone samples of lower slenderness ratio.
PL
Artykuł przedstawia wyniki wykorzystania wysokorozdzielczej mikrotomografii komputerowej w analizie strukturalnej oraz ilościowej przestrzeni porów i szczelin w piaskowcach mioceńskich. Dodatkowo wykonano badanie przepuszczalności analizowanych skał. Próbki zostały pobrane z odwiertu S-3, zlokalizowanego we wschodniej części zapadliska przedkarpackiego. W celu przeprowadzenia badania wykonano dwie serie naświetlania rentgenowskiego próbek. Pierwszy zestaw próbek został wytypowany dla uzyskania przestrzennego rozkładu ziaren, porów oraz szczelin. Długość boku woksela (tzn. najmniejszego elementu objętości) w tym etapie badań wynosiła około 26 μm. Drugi zestaw naświetlania został wykonany dla zobrazowania elementów strukturalnych o wielkościach od około 3 μm do 26 μm oraz cech petrofizycznych. Wynikiem przeprowadzonych badań jest charakterystyka analizowanych skał, która umożliwia podział próbek na dwie grupy. Pierwsza grupa próbek posiada cechy strukturalne oraz petrofizyczne typowe dla skał złóż konwencjonalnych, natomiast druga grupa – dla skał złóż typu niekonwencjonalnego. Właściwe rozpoznanie parametrów petrofizycznych każdego typu złoża stanowi kluczowy element optymalizacji procesu jego udostępniania.
EN
The article presents results of high-resolution computed microtomography use in the structural analysis and quantification of pores and fractures in Miocene sandstones. Furthermore, the permeability studies of rocks were performed. Miocene samples were taken from well S-3, located in the eastern part of the Carpathian Foredeep. For the aforementioned analysis two series of X-ray irradiation were performed. The first set of samples was selected to obtain the spatial distribution of grains, pores and fractures. At this stage of the study, the length of the voxel side amounted to approx. 26 μm. The second set of X-ray exposure was performed to reveal structural elements and petrophysical characteristics of sizes ranging from approx. 3 μm to 26 μm. The result of performed characteristics is the division of samples into two groups. The first group of samples has structural and petrophysical features of rocks typical for conventional reservoir deposits, while the second – for the unconventional type. Appropriate identification of petrophysical parameters of the formation is a key element for the optimization of the reservoir development.
EN
Upper Miocene sandstones in the Sava Depression (Northern Croatia) are potential targets for carbon dioxide (CO2)-based enhanced oil recovery (EOR) processes or mineral carbonation with reservoir brine. In general, sandstone lithology, even rich with aluminosilicate minerals, is not the most favourable rock medium for efficient sequestration of CO2 in minerals. However, CO2 is naturally sequestered in minerals when CO2 is injected into sandstone reservoirs and subdued to carbonation. The timescale of such sequestration is on the order of 104–105 years. Upper Miocene sandstones in the Sava Depression could incorporate up to 25% of aluminosilicate minerals (10% K-feldspars) and up to 20% dolomites and often laterally transition between pelitic and psammitic lithofacies, rich in clay minerals (15% micas). Total volumes are approximately 107 and 62 million m3 (approximately 268 and 155 million t of rocks), respectively for the potential injection reservoirs in the Ivanić Field. Oil saturation in the injection intervals is estimated to be approximately 14.8 and 4.1 million m3 respectively. Geochemical analogies and mineralogy can be used to support predictions for the low percentages of injected CO2 that may be stored during carbonation and form secondary minerals
EN
The Upper Badenian and Sarmatian sandstones recognized from boreholes in southeastern Poland and western Ukraine are very fine to medium-grained subarkosic and sublithic arenites and wackes. The deposits underwent diagenesis well below 100°C, and their evolutionary pathways of diagenetic and related reservoir properties represent eo- and mesodiagenesis. Eodiagenesis here comprised mechanical compaction, development of chlorite, microcrystalline calcite, pyrite, siderite, kaolinite and quartz, and dissolution of feldspar and mica grains. Mesodiagenesis included quartz and K-feldspar overgrowths, albitisation, crystallisation of dolomite and ankerite and coarsely crystalline calcite, dissolution of feldspar grains and carbonate cement, and illite growth. The isotopic data of δ18OVPDB of carbonate cements suggest their crystallisation from porewater which is a mixture of marine and meteoric waters. The δ13CVPDB values suggest derivation of carbon from microbial methanogenesis of organic matter. The 87Sr/86Sr values in coarsely crystalline calcite are higher than those of Badenian seawater. The radiogenic strontium may have been supplied during diagenesis by meteoric waters draining the continental area. The Middle Miocene sandstones show better filtration abilities (good and very good) in the western part of the study area (Poland) than in the east. Primary intergranular porosity is more frequent than secondary intragranular and intercrystalline porosities.The primary porosity was diminished due to compaction and cementation from west to east. Some increase in porosity was caused by dissolution of detrital grains and by decay of soft parts of organisms.
PL
Piaskowce dolnego karbonu strefy wielkopolsko-śląskiej to waki, rzadziej arenity, głównie sublityczne, lityczne i subarkozowe. Ich porowatość całkowita wynosi najczęściej 1–2%, a ich przepuszczalność jest bardzo niska. W skałach tych zaobserwowano ślady działania następujących procesów diagenetycznych: kompakcji, cementacji, a także zastępowania, przeobrażania i rozpuszczania składników. Piaskowce najbardziej perspektywiczne pod względem obecności gazu zamkniętego znajdują się w południowej i ­południowo-zachodniej części strefy wielkopolsko-śląskiej. Strop utworów karbonu w tych rejonach występuje przeważnie na głębokości do 3 km.
EN
The Lower Carboniferous sandstones of the Wielkopolska-Silesia zone are represented mainly by sublithic, lithic and subarkosic wackes and less frequent arenites. They are characterized by total porosity of mostly 1–2% and very low permeability. The effects of diagenetic processes such as compaction, cementation, replacement, alteration and dissolution have been distinguished in the investigated rocks. The most prospective tight gas sandstones occur in the south and south-western parts of the Wielkopolska-Silesia zone. The top of the Lower Carboniferous rocks does not exceed a depth of 3 km in these regions.
PL
Analizie petrograficznej i petrofizycznej poddano piaskowce z otworów wiertniczych położonych w strefie Szczecin–Radom. Piaskowce reprezentują głównie arenity i waki kwarcowe, od bardzo drobno- do średnioziarnistych. Głównym typem spoiwa są matriks oraz cementy, wśród których wyróżniono kwarc, węglany, minerały ilaste oraz lokalnie piryt. Największe znaczenie w piaskowcach jury dolnej odgrywa cement kwarcowy, tworzący obwódki syntaksjalne na ziarnach kwarcu. Autigeniczne minerały ilaste są głównie reprezentowane przez kaolinit robakowaty. Występowanie autigenicznego illitu oraz Fe/Mg chlorytów stwierdzono lokalnie. Cementy węglanowe są reprezentowane głównie przez wczesną i późną generację syderytu (minerał szeregu syderyt–magnezyt). Przeważa syderyt wczesnodiagenetyczny, reprezentowany przez syderyt oraz syderoplesyt. Wartości δ18C syderytu mieszczą się w przedziale od –24,50 do –4,56‰PDB, a wartości δ13O wynoszą od –14,37 do –0,33‰PDB. Miejscami występuje syderyt późny o składzie chemicznym syderoplesytu oraz pistomesytu. Ponadto występuje Fe-dolomit/ankeryt oraz sporadycznie kalcyt. Piaskowce jurajskie charakteryzują się bardzo dobrymi i dobrymi właściwościami filtracyjnymi. Dominuje w nich porowatość pierwotna, która często przekracza 20%, a przepuszczalność mieści się w przedziale od 0,001 do 1930,756 mD. Najważniejszymi procesami diagenetycznymi w piaskowcach są kompakcja, cementacja i rozpuszczanie. Kompakcja zredukowała porowatość pierwotną przeciętnie o około 30%, a cementacja – o około 21%.
EN
Sandstones from the boreholes located in Szczecin–Radom area have been subjected to petrographic and petrophysical analysis. Sandstones are represented mostly by quartz arenites and wacks, from very fine- to middle-grained. The main type of cements are matrix and cements, among which quartz, carbonates, clay minerals and locally pyrite were distinguished. Quartz cement occurring as syntaxial overgrowths developed on the quartz grains displays the greatest significance in the Lower Jurassic sandstones. Authigenic clay minerals are represented mainly by vermiform kaolinite. Authigenic illite and Fe/Mg chlorites are locally observed. Carbonate cements are represented mainly by early and late generation of siderite (mineral of series of siderite–magnesite). The early diagenetic siderite represented by siderite and sideroplesite is predominant. The siderite δ18C values are in the range from –24.50 to –4.56‰PDB and δ13O values range from –14.37 to –0.33‰PDB. The late siderite of pistomesite and sideroplesite chemical composition also occurs, but occasionally. Furthermore, there are Fe-dolomite/ankerite and occasionally calcite. The Jurassic sandstones are characterized by very good and good filtration properties. The primary porosity is dominant, it often exceeds 20%, and permeability is in the range of 0.001 to 1930.756 mD. The most important diagenetic processes operating in the sandstones are: compaction, cementation and dissolution. Compaction reduced primary porosity on average by about 30%, and cementation by about 21%.
PL
Na obszarze północno-zachodniego obrzeżenia Gór Świętokrzyskich w ostatnich latach nastąpił znaczący rozwój wydobycia piaskowców do celów architektonicznych i dekoracyjnych. Coraz większą popularność zyskują piaskowce jurajskie i kredowe województwa łódzkiego, które szturmem podbijają rynek kamieniarski. Charakteryzuje je interesująca barwa oraz korzystne parametry techniczne. Z ich udziałem zostały zrealizowane m.in. takie inwestycje jak: elewacja kina Praha w Warszawie czy kompleks budynków Murawa Office Park w Poznaniu. W artykule przedstawiono charakterystykę piaskowców jurajskich i kredowych w województwie łódzkim.
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