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PL
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.
EN
The possible occurrence of the Oldest Halite (Na1) unit of the Zechstein PZ1 cyclothem in the Kłodawa salt dome was a discussed matter for many years. Profiling and sampling of the evaporite Zechstein succession (a transition of PZ1 to PZ2 cyclothems) visible in a corridor of the "Kłodawa” Salt Mine at the mining level -650 m, located near the NE marginal pillar of the dome, were done in 2011. The studied section includes rock salt, shale, sulphate and carbonate rocks inclined at 60-90o to the NE and represents a normal succession of the PZ1 and PZ2 cyclothems. The normal succession of the top part of the PZ1 cyclothem consists of two lithological units: 1) rock salt complex (extending over a distance of ca. 5.8 m), defined as the Oldest Halite (Na1) lithostratigraphic unit, and 2) anhydrite bed, c.a. 1.3 m thick, distinguished as the Upper Anhydrite (A1g). These deposits are overlain by 4 lithological units, considered as those creating the normal sequence of the lower part of the younger PZ2 cyclothem. The first one is a dolomitic shale bed, ca. 3.7 m thick, defined as the Stink Shale (T2). It is overlain by a dolomite layer, 0.3-0.5 m thick, representing the Main Dolomite (Ca2), and by an anhydrite series, over 17 m thick, attributed to the Basal Anhydrite (A2). The studied section ends with a rock salt complex, ca. 4 m thick, interpreted as the Older Halite (Na2). The bromine (Br) content in both salt units is relatively low: 81-86 ppm (7 samples) in the Na1 unit and 54-77 ppm (4 samples) in the Na2 unit, with a distinct upward-increasing trend in the latter. Similar low Br values and their distribution trends were characteristic for the top of the Na1 standard bromine curve in Poland and for the lower part of such curve for the Na2 salts. This geochemical similarity could support a proper stratigraphic position of both units. The analysed section was interpreted as a tectonic slice or intrusion, composed of Na1 rock salt overlain with the younger A1g sulphate, incorporated within the folded complex of Na2 rock salt. Such image confirms the current opinion of a more complicated internal structure of the so-called "marginal anticlines” within the Kłodawa dome, composed of intensively folded both salt units. It also documents that the oldest Zechstein evaporites (chlorides and sulphates) could occur above within the dome section than was stated earlier.
EN
The upper Olenekian-Middle Triassic succession of the Tatricum domain (Central Western Carpathians, southern Poland) includes a few horizons of breccias, which are intercalated with early-diagenetic dolostones. On the basis of macroscopic and microscopic (including cathodoluminescence) observations, the paper presents a new interpretation of the genesis of the breccias and their diagenetic history. The rocks studied range from monomictic, cemented mosaic packbreccias to chaotic, unsorted, monomictic, particulate rubble floatbreccias. The processes that preceded the formation of the breccias encompassed the precipitation of evaporites and the early-diagenetic dolomitization of lime muds. The solution-collapse breccias were formed during episodes of cyclic sediment emersions in the upper Olenekian and Middle Triassic, as the result of gradual sediment collapse after karstic dissolution of the intercalated evaporites. After the brecciation process, during diagenesis the rocks were subjected to cementation by sulphate minerals and next, to multi-stage dolomitization. Later tectonic processes led to fracturing and even re-brecciation of the previously formed solution-collapse breccias.
PL
Utwory ewaporatowe (siarczany i sole kamienne) cyklotemów PZ1, PZ2 i PZ3 cechsztynu występują w NW części rowu mazursko-lubelskiego (SE Polska), dla którego skonstruowano w latach 2012-2016. model 3D budowy geologicznej. Dostępne dane z otworów wiertniczych (karotaże, opisy rdzeni wiertniczych i prób okruchowych) pozwoliły ustalić warunki (głębokość, miąższość) i przypuszczalny zasięg występowania tych utworów oraz wyróżnić 8 typów facjalnych, reprezentujących różne środowiska depozycji. Opracowane mapy rozmieszczenia poszczególnych typów facji dla każdego z ewaporatowych wydzieleń litostratygraficznych oraz 3D wizualizacje rozmieszczenia głównych komponentów litologiczno- facjalnych wymienionych cyklotemów umożliwiły przedstawienie zmian środowisk depozycji w kolejnych cyklach cechsztynu w tej części rowu mazowiecko-lubelskiego.
EN
Evaporites (sulphates and halites) of Zechstein PZ1, PZ2 and PZ3 cyclothemes occur in the NW part of Mazovia-Lublin Graben (SE Poland), for which the 3D model of geological structure was created in 2012-2016. Available geological data from boreholes (well logs and descriptions of cores and crushed rock samples) enabled to precise the occurrence parameters (depth and thickness) and the supposed extent of studied evaporites as well as to define 8 facies types, represented various depositional settings. Several maps, illustrating facies distribution of each evaporitic lithostratigraphic unit, supported with 3D images of main lithological-facies components of mentioned cyclothemes allowed to comment the environmental changes in the Mazovia-Lublin Graben area during evaporitic periods of studied cyclotheme successions.
5
Content available remote Ewaporaty Katalonii 2014 – wyprawa Polskiego Stowarzyszenia Górnictwa Solnego
PL
Celem kolejnej wyprawy Polskiego Stowarzyszenia Górnictwa Solnego w 2014 roku było poznanie geologii utworów ewaporatowych, w tym też soli, w rozległym trzeciorzędowym basenie katalońskim na przedpolu Pirenejów. Basen ten wykazuje pewne analogie w budowie i rozkładzie facji do polskiego zapadliska przedkarpackiego, lecz jego gigantyczne rozmiary i długa historia rozwoju sprzyjały powstaniu osadów potasonośnych. Podczas bogatego programu badań terenowych poznano wykształcenie utworów siarczanowych z obrzeża basenu salinarnego (gipsy w rejonie Odena i Vilobi) oraz serii potasonośnych z centrum panwi ewaporacyjnych (czynne kopalnie soli potasowych w Suria i Sallent oraz kopalnia-muzeum w Cardona). Facje klastyczne krawędzi basenu katalońskiego były widoczne w ścianach stromych klifów góry Montserrat.
EN
Following expedition of the Polish Salt Mining Association in 2014 was dedicated to geology of evaporites, especially the salts, developed in the giant Tertiary Catalonian Basin (Fig. 1) located on the Pyrenean foreland. This basin has same analogies in its structure and facies pattern to the Polish Carpathian Foredeep, but its extent and the long history favoured generation of potash-bearing sediments (Fig. 2). The numerous field stops of geological tour enabled to study the development of sulphate deposits from the salinary basin margin e. g. gypsum from Odena (Figs 6-7) and Vilobi (Figs 14-17) and of the potash-bearing series from the evaporite pans in the active potash mines in Suria (Fig. 3, 5), Sallent (Fig. 4) and in the old mine-museum in Cardona (Figs 8-11). The clastic facies of the Catalonian basin frames were visible in the steep cliff walls of Montserrat Mountain (Fig. 12).
EN
Seismic data and core from the shallow cartographic Pilzno P-7 borehole were used to construct a new model of the Carpathian orogenic front between Tarnów and Pilzno, in the Pogórska Wola area (southern Poland). The most external, frontal thrust of the orogenic wedge (the Jaśniny structure) was identified as a syn-depositional fault-propagation fold de- tached above the Upper Badenian evaporites. Its formation was controlled by the presence of mechanically weak foredeep evaporites and by the morphology of the sub-Miocene Meso-Paleozoic foreland plate (Jaśniny and Pogórska Wola palaeovalleys). The frontal zone of the Carpathian orogenic wedge (the Skole thrust sheet and the deformed foredeep deposits of the Zgłobice thrust sheet) is characterized by significant backthrusting of the foredeep succession towards the south, and by the presence of a triangle zone, with strongly deformed Upper Badenian evaporites of the Wieliczka Formation in its core. The triangle zone was formed during the latest thrusting movements of the Carpathians. An indication of the existence of the triangle zone in the vicinity of Dębica has also been provided by reinterpretation of the archive regional geological cross-section. The youngest foredeep deposits, brought to the surface above the backthrust, have been dated as Sarmatian (NN7 nannoplankton zone), which indicates that the latest thrust movements within the frontal Carpathian orogenic in the vicinity of Tarnów-Dębica took place approx. 11-10 million years ago. Thermochronological studies (AFT and AHe) indicated that the foredeep succession drilled by the Pilzno P-7 borehole has not been buried deeper than 1.5-2 km, which is compatible with reconstruction based on the seismic data.
EN
The development of basal Zechstein (Wuchiapingian) strata inSW Polandindicates the existence of a diversified relief inherited after the flooding of the pre-existing depression by the transgressing Zechstein sea. The deeper parts of the basin were the place of development of thin basinal Zechstein Limestone showing sedimentary condensation manifested by bored and encrusted grains and thick evaporites (mostly halite), and in shallow parts Zechstein Limestone reefs followed by thinner evaporite sequences (dominated by anhydrite) occur. The analysis of 3D seismic sections showed that instead of three conventionally recognized evaporite units of stratigraphic potential in the PZ1 cycle, five units occur (from the base to the top: Lower Anhydrite, Lower Oldest Halite, Middle Anhydrite, Upper Oldest Halite, Upper Anhydrite). In a particular place their number may vary from two (Lower Anhydrite at the base of the PZ1 cycle and Upper Anhydrite at the top of the PZ1 cycle) to five. There are two complexes of Lower Anhydrite occurring throughout the platform and basinal zones showing deepening-upward (transgressive) trend. The halite sedimentation in the deepest parts of salt basins began shortly after the deposition of the upper Lower Anhydrite complex while in the sulphate platform areas the sulphate deposition lasted still for a long time. The Lower Oldest Halite deposits occur in the depressions. Between the halite basins, anhydrite platforms occur, and the thickness of anhydrite platform deposits is smaller than it is observed in salt basins. The Upper Oldest Halite in turn is recorded above the anhydrite platform. The two halite units represent different phases of development of halite basins. The Lower Oldest Halite basins are related to the pre-Zechstein depressions, although in some cases their syndepositional subsidence was controlled by reactivation, during the deposition of basal Zechstein strata, of former faults. In turn, the Upper Oldest Halite basins used the accommodation space created due to anhydritization of the Lower Anhydrite deposits composed originally of selenitic gypsum. The 3D seismics evidences that the PZ1 evaporites inSW Polandhave been deposited in far more complex and dynamic system than it was assumed before.
EN
Anhydrite is widespread in the Prypiać Trough in the form of beds and nodules in the Subsaliferous Terrigenous and Carbonate formations (Eifelian and Frasnian), the Lower Saliferous Formation (Frasnian), the Intersaliferous and Upper Saliferous formations (Famennian). It is also present in the Asselian and Sakmarian (Lower Permian) deposits of the trough. The anhydrite is grey, blue, pink and orange. It has massive and, more rarely, horizontal bedding, and a fine- and micro-crystalline structure. Gypsum extends widely across the Orša Depression, Žlobin and Latvijas Saddles and partly in the Belarusian Anteclise, where it lies within the Eifelian deposits. It is also found in the Frasnian strata of the North-Prypiać Shoulder. As a component of facial analogue of the Upper Saliferous Formation gypsum forms the Bryniou deposit in the west of the Prypiać Trough. This mineral is also observed in the Oversaliferous Formation (Famennian) and in the Asselian and Sakmarian strata of the trough. There are spar, saccharoidal, alabastrine and selenitic varieties of gypsum. A medium to coarse crystalline structure is typical. The gypsum is grey, pink, yellow or orange.
9
Content available Pomiary XRMI w utworach cechsztynu
PL
Pomiar XRMI bazuje na kontraście mikroopornościowym skał. Sonda jest nazywana przyrządem „o rozszerzonym zakresie", ponieważ daje bardzo dobrej jakości obraz ściany otworu, nawet w formacjach o wysokiej oporności (>2000 Ω.m) i przy stosowaniu zasolonych płuczek o relatywnie niskich opornościach (<0,l Ω.m). Dzięki dużej rozdzielczości pionowej pomiarów sonda ta daje możliwość interpretacji powierzchni warstwowania wraz z informacją o tym, w którym kierunku i pod jakim kątem są one nachylone oraz zidentyfikowania fałdów, uskoków i mikrouskoków, spękań, niezgodności kątowych. Na obrazach mikroopornościowych zaznaczają się również struktury powstałe w wyniku odwiercenia otworu: szczeliny indukowane, struktury wykruszeniowe typu breakouts, ślady świdra. Pomiary sondą XRMI mają wiele zastosowań w interpretacji strukturalnej i sedymentologicznej, mogą dostarczać również informacji o właściwościach mechanicznych górotworu, przydatnych zarówno w procesach wiercenia otworu, jak i podczas zabiegów szczelinowania.
EN
The XRMI measurement relies on micro-resistance contrast of rocks. The system is called the "X-tended Range Micro Imager" because it gives a very good quality borehole wall images even in highly resistive formations (>2000 Ω. m) and relatively low-resistance salty mud (<0.1 Ω. m). Owing to a high vertical resolution of measurements, this tool allows for interpretation of bedding surfaces, with information about their dip angle and azimuth, as well as recognition of folds, faults and micro-faults, fractures, and angular unconformities. The images also show structures resulting from well drilling: induced fractures, breakouts, or bit marks. XRMI measurements are applied in both structural and sedimentological interpretations, and they can give some geomechanical information helpful in borehole drilling and hydraulic fracturing.
EN
To establish the brine chemistry associated with the evaporites in the Pennsylvanian Paradox Basin of southeastern Utah and southwestern Colorado (USA), the composition of primary fluid inclusions was determined for sedimentary halite from two drill cores, one near the central part of the basin (Shafer Dome No. 1) and one from a more marginal location of the basin (Gibson Dome No. 1). Chemical analysis of halite fluid inclusions was done on six samples from three different evaporite cycles of the Paradox Formation; cycle 10 in the Shafer Dome core and cycles 6 and 18 from the Gibson Dome core. The inclusions that range in size from 2 to 80 microns across, were analyzed using the Petrychenko method. Large inclusions (40 to 80 microns across) that were used for the chemical analyses contain one fluid phase with a carnallite or sylvite daughter crystal. Also reported in this study are fluid inclusion homogenization temperatures for sylvite or carnallite from primary halite crystals in the Gibson Dome core and in Shafer Dome. The relationship between K+ and Mg2+ in chloride rich inclusions corresponds to their proportion in MgSO4-depleted marine waters concentrated to the stage of carnallite deposition. A correlative relationship was observed between K+2+4-rich to MgSO4-poor compositions that have been proposed by other workers. A transition from MgSO4-rich to MgSO4-poor seawater composition may have occurred between Pennsylvanian and Permian times. This paper presents a possible alternate explanation to those already proposed in the literature, that the Paradox Formation mineralogy resulted from an intermediate seawater composition that records the global transition from MgSO4-rich to MgSO4-poor seawater.
PL
W strukturach wzrostowych halitu typu szewron w basenie zakarpackim (Ukraina) stwierdzono występowanie pierwotnych inkluzji, które mogą być pomocne przy określeniu składu chemicznego solanek badeńskiego basenu ewaporatowego. Ciekłe inkluzje występujące w sedymentacyjnym halicie badane były metodą analizy ultramikrochemicznej. Koncentracja solanek zakarpackiego basenu była wysoka - zbliżona do średniego etapu sedymentacji halitu. Zawartość jonów: K+ zawierała się w przedziale 10.6-17.6 g/l, Mg2+ w zakresie 31.4-58.3 g/l, a SO4 2- w przedziale 22.4-39.0 g/l. Na podstawie badań składu chemicznego głównych jonów stwierdzono, że solanki basenu zakarpackiego były nasycone względem halitu i podobne do solanek z innych badeńskich basenów.
EN
The primary fluid inclusions, which may be helpful in detemining the chemical composition of brines in the Badenian evaporite basin, were found in the chevron halite crystals from the Transcarpathian Basin (Ukraine). Fluid inclusions in sedimentary halite were examined with the use of ultra-microchemical analysis. Concentration of brines was high - close to the middle stage of halite sedimentation. The content of ions: K+ ranged from 10.6 g/l to 17.6 g/l, Mg2+ from 31.4 g/l to 58.3 g/l, and SO4 2- from 22.4 g/l to 39.0 g/l. Based on the chemical composition of major ions it was concluded that the brine from the Transcarpathian basin was saturated (to the stage of halite crystallization) and was similar to the Badenian brines from other basins.
12
Content available Ewaporaty cechsztynu PZ1- PZ3 bloku Gorzowa
EN
The Gorzów Block (West Poland) occurs in the transition zone between the PZ1 sulphate platform and the Na2 basin. In contrast to the western part of the Southern Permian Basin where the Z1 halite (Oldest Halite Na1) is normally restricted to the peripheral subbasins located south of the main basin, in Poland it occurs both in the basin centre and in the former basins of the Lower Anhydrite within the marginal sulphate platform complex, where halite sequences are thick and may have originated in a deep-water setting. The Na1 deposits have been considered so far to be LST deposits both in the marginal sulphate platform facies as well as in the basin centre. Brine salinities (and the minerals they precipitate) are controlled by brine residence times in the basin, and these are determined primarily by the absolute and the relative rates of water flow into, and brine flux out of the basin (Kendall, 2010). Thus sea-level rise in the Boreal Sea could have resulted in the increase of the brine residence times in the Zechstein basin and the deposition of more saline evaporites. Consequently, the Oldest Halite in the basin centre in Poland is regarded as the TST deposit.
EN
Strontium isotope compositions have been measured in six primary gypsum samples from the most marginal part of the Badenian evaporite succession in the Ukrainian Carpathian Foredeep Basin (Mamalyha quarry section) and in two anhydrite samples from the basin-centre halite zone of the Ukrainian Carpathian Foredeep, aimed determining the origin of brines from which these sulphates were precipitated. The strontium isotope ratios (87868868761887 6878786
15
Content available Ewaporaty : nowe dane mineralogiczno-petrograficzne
PL
Badania ewaporatów prowadzone są bardzo intensywnie zarówno ze względu na to, że są to surowce niezmiernie cenne dla wielu dziedzin gospodarki, lecz także, a może głównie ze względu na to, że z ewaporatami często współwystępują złoża ropy i gazu. Zrozumienie wielu zjawisk występujących w czasie sedymentacji, diagenezy, a także metamorfizacji ewaporatów ma podstawowe znaczenie poznawcze i przyczynia się do poprawnych decyzji związanych z poszukiwaniem obu wspomnianych paliw. W publikacji zaprezentowano różne rodzaje zbiorników ewaporacyjnych i różne sposoby naturalnego zagęszczania słonej wody. Przedstawiono także różne rodzaje kryształów pochodzenia ewaporacyjnego wskazujące na różne sposoby krystalizacji ewaporatów. Zaprezentowano także przykłady krasu solnego i omówiono sposoby krystalizacji form pochodzenia krasowego krystalizujących z minerałów ewaporacyjnych.
EN
Research on evaporates is conducted very intensively, which is both due to the fact that they are of utmost value to many branches of economy, and also (and this seems to be the main reason) that often deposits of oil and gas are found close to evaporites. Hence the comprehension of phenomena may contribute, in a fundamental way, to correct decisions related to the exploration of both fuels. The publication deals with various theories concerning functioning of evaporate basins and various way of salty water condensation. Moreover various types of evaporate crystals representing differentiated way of evaporate formation and crystallization are presented. Additionally examples of karstic forms crystallizing at salt main are described and the way of their crystallization is explained.
EN
Fluid inclusions in halite from Miocene rock salt of the Ukrainian Carpathian Foredeep Basin in locations where evaporites overlie oil and gas reservoir rocks are characterized by their high methane content and the presence of oil droplets in some of them. They are thus similar to fluid inclusions reported from geochemical aureoles around oil and gas accumulations in the Zechstein (Upper Permian) of western Poland (Kovalevych et al., 2008). Geochemical analyses of bitumen in bulk samples of rock salt (including content and distribution of n-alkanes and isoprenoids, carbon isotope ratios) suggest a varied origin: hydrocarbon extracted from halite from boreholes located in proximity (proved or assumed) of oil and gas deposits (Lopushna-7, Grynivka-525) are probably related to organic material dispersed within the rock salt itself, and those from the barren areas (Verkhniy Strutyn-29) are most probably cogenetic with oil accumulated in the deposits of the Boryslav-Pokuttya Nappe.
17
Content available remote Sedymentacja ewaporatów badeńskich w zbiorniku przedkarpackim
EN
Badenian evaporites of the Carpathian Foredeep Basin represent the lower part of the NN6 zone and are underlain and overlain by deep-water deposits. Halite and associated deposits in the central part of the Badenian evaporite basin show the same facies successions and marker beds can be traced across and between individual basins. Characteristic marker beds made it possible to correlate various facies zones of the marginal Ca-sulfate platform. These marker beds seem to reflect events that may be related to sudden and widespread changes in water chemistry, which in turn imply major changes in basin hydrology. The onset of the evaporitic deposition in the Carpathian Foredeep was clearly diachronous and the evaporites deposited in the basin centre preceded the beginning of evaporite sedimentation in the marginal basin, however, depositional history in the marginal basin and the basin center was the same. Sedimentological and geochemical data indicate recycling of evaporites throughout most of the evaporite deposition.
EN
Published sulphur and oxygen isotope age curves for the late Neoproterozoic-Early Cambrian time interval have been based on studies of sulphate intervals of the East Siberian salt giant. We report here on sulphur and oxygen measurements for sulphate dispersed in, or forming laminae in, the rock salt deposits in all Lower Cambrian basins of East Siberia. Sulphur isotope data for 26 samples of Lower Cambrian anhydrites from East Siberia range from +22.6 to +34.5‰. No difference was observed between different suites and between samples taken from anhydrite intercalations in rock salt and from water-insoluble residue in rock salt. Oxygen isotope data for 25 anhydrite samples range from +12.4 to +17.8‰, and thus δ18 O values have a smaller range of variation (5.5‰) than δ34 S (11.8‰) over the entire set of Lower Cambrian anhydrites. The great δ34 S variability observed in the Lower Cambrian of Siberia seems to reflect mixing of sulphates coming from the ocean and due to the riverine input. The lowest δ18 O values may indicate the input values from both the sources, whilst the highest value may result from isotope exchange between SO4 2- and water. Our results combined with data provided by previous workers could indicate a clear stratigraphic trend in δ34 S values, with a remarkable fall of ca. 9‰ in δ34 S value during the earliest Cambrian and then a slight rise in δ34 S values in the younger part of Early Cambrian. However, if only the highest values are taken, the measured values are compatible with seawater δ34 S 3 30‰ during the entire Early Cambrian. Sulphur isotopic composition of sulphate minerals did not be come heavier from the sulphate stage to ward the chloride stage.
EN
Facies analysis was applied to the six main facies of the Badenian (Middle Miocene) gypsum deposits exposed along the margin of the Carpathian Foredeep basin, from Moldova to the Czech Republic. These facies, recognised within primary selenite and fine-grained gypsum deposits, are: (i) selenites with vertical crystals; (ii) selenites with horizontal crystals; (iii) selenite debris flow facies; (iv) selenite debris facies; (v) gypsum microbialite facies; and (vi) alabastrine facies. The facies represent various environments (from shallow-brine to subaerial) of a giant salina-type basin without open-water connections with the sea and showing evaporite drawdown. Integration of facies analysis and event stratigraphic studies in the gypsum basin allowed reconstruction of its sedimentary history.The architecture of the gypsum facies suggests that the margin of the basin was occupied by a system of variable perennial saline pans (dominated by selenite deposition) and evaporite shoals (dominated by gypsum microbialite deposition). The basin was infilled with evaporite deposits by aggradation. After initial evaporite drawdown, the northern margin of the basin evolved from a large perennial saline pan (or system of pans) into an evaporite shoal and then back again into a perennial pan, whereas the east area of the basin was a vast evaporite shoal dominated by gypsum microbialites. Separate selenite pans of oligotrophic-type developed both at the periphery and in the interior of this shoal. Later, predominantly clastic gypsum deposition developed throughout the basin margin, presumably due to a drastic change in the chemistry and salinity of the brine. Evaporite deposition was arrested by a flood of marine waters and rapid deepening.
EN
The Middle Miocene (Badenian) evaporites of the northern Carpathian Foredeep were deposited in a salina-type basin. Calcium sulphate sediments were deposited mainly on the broad northern margins of the basin, on vast evaporite shoals (mainly as fine-grained microbialite gypsum) and in large shallow saline pans (as coarse-crystalline selenites). 125 sections of these primary deposits, exposed from Moldova, Ukraine, Poland to the Czech Republic, were subjected to stratigraphic analysis based principally on the methodology of event and high-resolution stratigraphy. Due to an extremely gentle relief and a predominantly aggradational type of deposition, typical of a salina basin, the environmental changes or events were recorded nearly instantaneously in the whole area. Some events, such as water-level or brine-level fluctuations (emersions and floods, which can be very rapid in a salina basin),fluctuations in the average pycnocline level, aeolian dust or ash falls, accretion of specific gypsum microbialites, produced sets of marker beds which are perfectly correlated over distances of tens to hundreds of kilometres. Some thin grass-like selenite beds, representing deposits of shallow flat-bottomed saline pans, were correlated precisely over such great distances and are interpreted as isochronous or near-isochronous. Each bed was presumably deposited during the average pycnocline level highstands in the saline pan. The thick-bedded selenite units do not show long-distance bed-by-bed correlation, presumably because they were deposited in deeper pans in which the pycnocline fluctuations were recorded by bedding planes (i.e. by intercalations of fine-grained gypsum or dissolution surfaces) only on the shallow slopes or swells. However some apparent growth zones in the gypsum crystals from such selenite units were correlated throughout the basin, proving that the selenite growth However some apparent growth zones in the gypsum crystals from such selenite units were correlated throughout the basin, proving that the selenite growth was isochronous.
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