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Tadeusz Marek Peryt - One of the best experts on this subject based on the ideXlab platform.
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sulphur and oxygen isotope signatures of late permian zechstein Anhydrites west poland seawater evolution and diagenetic constraints
Geological Quarterly, 2011Co-Authors: Tadeusz Marek Peryt, Stanislaw Halas, Sofiya P HrynivAbstract:The stable oxygen and sulphur isotope ratios of 52 Anhydrite samples from three Zechstein Anhydrite units (Lower Anhydrite, Upper Anhydrite and Basal Anhydrite) of West Poland show d18 O values vs. VSMOW in the range of 9.4 to 15.5 (mean of 12.6 ą1.3), and d34 S values vs. VCDT between 9.6 to 12.6 (mean of 11.4 ą0.6). A generally uniform distribution pattern of both isotopic values throughout the section, although with some random variation, implies that sulphate ions were sufficiently supplied and the basin was open during sulphate deposition. There is a slight stratigraphic differentiation of both the d18 O and d34 S values: the highest mean values are shown by the Upper Anhydrite and the lowest average values occur in the Basal Anhydrite. The correlation between d18 O and d34 S values is statistically significant only in case of the Basal Anhydrite. A wide range of oxygen isotopic ratios (from 11.6 to 25.1), with only several samples having d18 O values that fall within the range of late Permian seawater, have been recorded in Anhydrite cements and nodules that occur in the Main Dolomite rocks. Sulphur isotope ratios of Anhydrite cements (range of 7.6 to 12.9, average of 10.7 ą1.4) tend to reflect the late Permian sulphur isotopic signature of sulphate in seawater. The higher ranges of d18 O and d34 S values of Anhydrite cements and nodules in the Main Dolomite compared to the underlying and overlying Anhydrites are due to diagenetic resetting. The conversion of gypsum to Anhydrite (often very early and under negligible cover) evidently did not affect the primary marine stratigraphic sulphur isotope composition of the sulphate deposits.
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strontium distribution and celestite occurrence in zechstein upper permian Anhydrites of west poland
Chemie Der Erde-geochemistry, 2010Co-Authors: Sofiya P Hryniv, Tadeusz Marek PerytAbstract:The previous study showed that the Zechstein (Upper Permian) Anhydrites have about 0.2% strontium with a remarkably small sample scatter. Our study of three lower Zechstein Anhydrite units (Lower Anhydrite, Upper Anhydrite and Basal Anhydrite) from West Poland indicate that although often the Sr content is 0.1–0.2%, there are common deviations. In particular, a considerable part (28%) of the studied samples is characterized by lower values (<0.1%), and on the other hand ca. 15% of samples are Sr-enriched, and in those samples celestite was recorded. Particular Anhydrite levels differ especially in the frequency of samples showing great Sr content. The greatest variation was found in the Lower Anhydrite. This agrees well with the conclusion derived from the sedimentological studies indicating that there was the greatest differentiation of depositional environments during the deposition of the Lower Anhydrite. The Sr content is a good indicator of brine concentration during the gypsum precipitation and it seems that the subsequent gypsum–Anhydrite transformation itself does not affect the strontium distribution. The histograms of Sr content in the Basal Anhydrite indicate a slightly higher brine concentration than it was during the Lower Anhydrite deposition, and the latter in turn was higher than brine concentration during the Upper Anhydrite sedimentation. Celestite veins are clearly diagenetic in origin. The form of celestite occurrence and the increased strontium content (1% or more) indicate an additional source of ions that occurred outside the Anhydrite series. In the case of the Lower Anhydrite, the supposed additional source of Sr was related to aragonite-to-calcite transition and squeezing of CaCl2 brines from reefs into Anhydrite series due to increased pressure. For the Basal Anhydrite this source could be related to brines derived from the Older Halite deposits.
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sulfate cavity filling in the lower werra Anhydrite zechstein permian zdrada area northern poland evidence for early diagenetic evaporite paleokarst formed under sedimentary cover
Journal of Sedimentary Research, 2003Co-Authors: Sofiya P Hryniv, Tadeusz Marek PerytAbstract:ABSTRACT Paleokarst developed in sulfate deposits is common, and it is usually formed along the contact with the overlying permeable rocks or it is due to near-surface dissolution of bedded evaporites. In the Lower Werra Anhydrite (Zechstein) of northern Poland the paleokarst cavities are usually filled by bluish semitransparent Anhydrite and more rarely by celestite, polyhalite, halite, and carbonate. In small cavities (a few centimeters across), a rim of rod-like Anhydrite crystals arranged in narrow bundles occurs, and the inner part of the cavity is filled with a mosaic aggregate of short prismatic crystals of Anhydrite and celestite as well as coarse irregular Anhydrite. Celestite crystals and fan-shaped aggregates as well as spherulites of Anhydrite are rare. In bigger cavities (some ten centimeters across), multiple zones of fibrous Anhydrite are arranged in different directions in the middle part of the cavity fill. The innermost parts of large karst cavities remain hollow in some cases, with the cavity walls encrusted by coarse, well-developed crystals of Anhydrite and celestite. The karst cavities in the Lower Werra Anhydrite developed in the subsurface by dissolution of CaSO4 strata in halite-rich intervals due to gypsum dehydration water. During gypsum dehydration, dissolution of that halite would have increased the sodium chloride content of the solution and thus the solubility of calcium sulfate. Dissolved calcium sulfate was removed from a leaching zone by diffusion and/or downward flow in interstitial space, and the minerals in karst cavities precipitated from the same solutions as those solutions became oversaturated because of decreases in NaCl concentration over time. This study suggests that karst in sulfate deposits can develop in the subsurface and without uplift and/or near-surface conditions.
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the anatomy of a sulphate platform and adjacent basin system in the leba sub basin of the lower werra Anhydrite zechstein upper permian northern poland
Sedimentology, 1994Co-Authors: Tadeusz Marek PerytAbstract:The Lower Werra Anhydrite (Zechstein, Upper Permian) deposits of the teba area originated in a deep basin setting, in shallow to deep water conditions. Facies changes occur within small distances and suggest fluctuating boundaries between well defined basins and platforms. This pattern of local platforms and adjacent basins developed during deposition. In basinal areas, the sequence is clearly transgressive, whereas on platforms accumulation kept pace with subsidence after an initial transgression. Nodular Anhydrite represents a polygenetic deposit which formed at different times with respect to deposition. Massive Anhydrite with pseudomorphs after upright-growth gypsum crystals suggest rapid precipitation in a subaqueous environment and/or fluctuating, but generally high, salinity conditions. Massive clastic sulphate originated due to periodic high energy events and resedimentation, or due to brecciation possibly connected with salinity fluctuations and the dissolution of halite. Massive, textureless Anhydrite is locally porous and passes upward into breccia, indicating a strongly saline environment. Bedded Anhydrite is considered to form in shallow water environments and laminated Anhydrite in deep water. Bedded Anhydrites contain portions which are graded. Intercalations of sulphate turbidites and upright-growth gypsum suggest fluctuating water depths, with comparatively deep water during turbidite deposition, but shallower conditions during upright-growth gypsum deposition. The sequence observed in slope zones at platform-basin margins, detrital (parautochthonous) sulphate sand to graded beds to basinal laminites, indicates that redistribution processes were important. At the onset of the Lower Werra Anhydrite deposition bathymetric relief existed between the central part of the basin and its margins, where carbonate platforms remained subaerially exposed. Formation of local platforms and adjacent basins required a relatively high subsidence rate, as pre-existing relief cannot account for the total accumulated thickness of the Lower Werra Anhydrite deposits. One implication of this is that the main argument against ‘the shallow water - shallow basin’ evaporite basin model, i.e.,a very fast rate of subsidence, may not be valid for the Łeba Lower Werra Anhydrite basin.
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sulfate platform basin transition of the lower werra Anhydrite zechstein upper permian western poland facies and petrography
Journal of Sedimentary Research, 1993Co-Authors: Tadeusz Marek Peryt, Federico Orti, Laura RosellAbstract:ABSTRACT The peripheral evaporite platform of the Zechstein (Upper Permian) Werra Anhydrite of western Poland comprises a series of shoals (with thick sulfate deposits) and lows (with thin sulfate and thick halite deposits). Three cores were selected to examine facies variations from a sulfate platform, slope, and basin. The basal unit of the Lower Werra Anhydrite is represented by different varieties of nodular, bedded-nodular, fluidal-nodular, and brecciated facies. Some nodular fabrics probably originated within sabkha and/or gypsumpond environments, and the deposit was then mechanically redistributed. The absence of nodular structures in units other than the lower one in two of the wells suggests that the origin of these structures cannot be related to deep burial. Other units of the Lower Werra Anhydrite represent subaqueous deposits. The facies in the middle and upper units have no recent analog in coastal salina environments. Turbidity currents displaced sulfates from the platform to the adjacent basin. The origin of lenticular-bedded Anhydrite may be related to deformation by compaction or by ravitational instability and slumping, which may have initiated crystallization or recrystallization of Anhydrite. The vertical sequence of facies shows a distinct deepening-upward trend starting from the top of the basal nodular units. Deposition in shallow (salina) environments dominated the early history of the Lower Werra Anhydrite basin, although it was probably preceded by transgressive sabkha deposits. Relatively thick nodular Anhydrites probably formed by syndepositional diagenesis of probable salina deposits and minor sabkha sediments. Gypsum was the original sedimentary mineral; it was later transformed into Anhydrite, during either early or late (burial) diagenesis. We show that in deeply buried evaporites not only some macroscopic primary textures remain but also even microscopic details, which allow reconstruction of depositional environments and primary mineralogy of ancient Anhydrites.
Hao Zou - One of the best experts on this subject based on the ideXlab platform.
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origin of the early to middle triassic polyhalite minerals in the sichuan basin sw china new evidence from calcium and sulphur isotopes and microfabrics
Ore Geology Reviews, 2021Co-Authors: Daxing Gong, Bin Xiao, Leon Bagas, Jiayun Zhou, Hao ZouAbstract:Abstract Polyhalite is a special potash fertilizer resource, which is widely distributed in the Triassic evaporite strata in the Sichuan Basin, but its genetic mechanism has always been controversial. This contribution presents new petrological, geochemistry , electron probe analyses, and Ca-S isotope systematics on Triassic polyhalite minerals for the first time from the Sichuan Basin aiming to better understand their origin. We present petrological observations of long columnar and granular polyhalites co-existing with halites (rock salt) and Anhydrites that are not metasomatic in origin. Metasomatic polyhalites have also been studied, which have a fibrous and radial habit interwoven with Anhydrite. The primary (sedimentary) polyhalite is solely formed from the evaporation of seawater, and the formation of metasomatic polyhalite involved impure meteoric water . The Ca and S isotopic values show that the sulphur and calcium in diamond-drillholes ZK001 and ZK601 are derived from seawater, whereas the sulphur and calcium in Well YS01 are derived from meteoric water. The sulphur and calcium in Well ZK02 are derived weathered terrigenous gypsum . This study demonstrates that the combined sulphur (δ 34S) and calcium (δ44/40Ca) isotopes can be used to reveal the genesis of polyhalite.
Chunfang Cai - One of the best experts on this subject based on the ideXlab platform.
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effect of thermochemical sulfate reduction on carbonate reservoir quality cambrian and ordovician oilfield tazhong area tarim basin china
Marine and Petroleum Geology, 2021Co-Authors: Lianqi Jia, Chunfang Cai, Jingong Zhang, Lijing Liu, Qingyong LuoAbstract:Abstract Deep (4000–6000 m) and ultra-deep burial (>6000 m) carbonate reservoirs are becoming important petroleum exploration targets of China and worldwide basin. Thermochemical sulfate reduction (TSR) may be pervasive in the deep and ultra-deep burial petroliferous carbonate strata associated with evaporite. However, there is still considerable confusion on the effect of TSR on reservoir quality. Petrography, geochemistry and fluid inclusion data from carbonate reservoirs of Tarim Basin were integrated to resolve the disagreement. Based on distribution of sulfur-bearing mineral, SO42− concentrations and SO42−/Cl− ratios in both formation water and fluid trapped in fluid inclusion, we propose that SO42− in formation water is likely major reactant involved in TSR reaction of North Slope, whereas coarsely diagenetic anhydride is likely major sulfate reactant involved in TSR reaction of East Burial Hill Belt. Silurian fracture-filling pyrite has δ34S values similar to those of Ordovician fracture-filling pyrite, H2S and sulfur, suggesting that TSR dissolved sulfate involved in (North Slope) may occur in a partly open system for H2S and CO2. However, TSR diagenetic anhydride involved in (East Burial Hill Belt) may occur in a closed diagenetic system. TSR in a partly open-system, associated with gas charge and flow of cross formational fluids, probably increased fluid pressure, and further transported H2S, CO2 and solute from dissolution through fracture. A closed system of Anhydrite-bearing strata seems to hinder transports of TSR-derived CO2 or bicarbonate, and result in precipitation of TSR calcite, pyrite and bitumen close to the TSR sites. In combination with petrographic observations, intense dissolution in North Slope have released more inorganic CO2 leading to TSR calcite and CO2 in the natural gas showing δ13C values much heavier relative to δ13C values of TSR calcites in East Burial Hill Belt as light as −13.4‰. TSR-induced dissolution of carbonate minerals during oil-dominated TSR may be related to the reaction of dolomite with anhydride and release of H+ due to pyrite precipitation, rather than new formed water during TSR. Similar to geological settings of Ordovician TSR, Anhydrite-poor Lower Cambrian dolostones underlying evaporites seals may thus be the most promising target for future exploration success in ultra-deep Cambrian reservoirs of Tarim Basin. The controversy about the effects of TSR on reservoir quality can partly be ascribed to differently geological settings where TSR occurred.
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thermochemical and bacterial sulfate reduction in the cambrian and lower ordovician carbonates in the tazhong area tarim basin nw china evidence from fluid inclusions c s and sr isotopic data
Geofluids, 2015Co-Authors: Lianqi Jia, Chunfang Cai, H Yang, Tiankai Wang, Baoshou Zhang, Lei Jiang, X TaoAbstract:Petrographic features, C, O, S, and Sr isotopes were determined, and fluid inclusions (FI) were analyzed on various stages of vug- and fracture-fillings from the Cambrian and Lower Ordovician reservoirs in the Tazhong area, Tarim basin, NW China. The aim was to assess the origin of pyrite and Anhydrite and the processes affecting sulfur during diagenesis of the carbonates. Pyrite from seven wells has δ34S values from −22‰ to +31‰. The pyrites with low δ34S values from −21.8‰ to −12.3‰ were found close to fracture-filling calcites with vapor-liquid double-phase aqueous fluid inclusions homogenization temperatures (FI-Th) from 55.7 to 73.2°C, salinities from 1.4wt% to 6.59wt% NaCl equiv and δ13C values from −2.3‰ to −14.2‰, indicating an origin from bacterial sulfate reduction by organic matter. Other sulfides with heavier δ34S values may have formed by thermochemical sulfate reduction (TSR) during two episodes. The earlier TSR in the Middle and Lower Cambrian resulted in pyrites and H2S having δ34S values from 30 to 33‰, close to those of bedded Anhydrite and oilfield water (approximately 34‰). The later TSR is represented by calcites with δ13C values as light as −17.7‰ and FI-Th of about 120–145°C, and pyrite and H2S with δ34S values close to those of the Upper Cambrian burial-diagenetic Anhydrite (between +14.8‰ and +22.6‰). The values of the Anhydrite are significantly lighter than contemporary seawater sulfates. This together with 87Sr/86Sr values of Anhydrite and TSR calcites from 0.7091 to 0.7125 suggests a source from the underlying Ediacaran seawater sulfate and detrital Sr contribution.
Hongkun Zhao - One of the best experts on this subject based on the ideXlab platform.
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solid liquid equilibrium and phase diagram for the ternary 4 chlorophthalic anhydride 3 chlorophthalic anhydride ethyl acetate system
Journal of Chemical & Engineering Data, 2014Co-Authors: Ganbing Yao, Hongkun ZhaoAbstract:In this paper, the mutual solubility for ternary system of 4-chlorophthalic anhydride + 3-chlorophthalic anhydride + ethyl acetate was measured experimentally at different temperatures. Four isothermal phase diagrams of the system were constructed based on the measured solubility. At each temperature, there existed two pure solid phases, pure 4-chlorophthalic anhydride and pure 3-chlorophthalic anhydride, which were identified by the Schreinemakers’ wet residue method. When temperature decreases, the crystallization regions of 4-chlorophthalic anhydride and 3-chlorophthalic anhydride increase. At a certain temperature, the crystallization region of 4-chlorophthalic anhydride is smaller than that of 3-chlorophthalic anhydride.
Lianqi Jia - One of the best experts on this subject based on the ideXlab platform.
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effect of thermochemical sulfate reduction on carbonate reservoir quality cambrian and ordovician oilfield tazhong area tarim basin china
Marine and Petroleum Geology, 2021Co-Authors: Lianqi Jia, Chunfang Cai, Jingong Zhang, Lijing Liu, Qingyong LuoAbstract:Abstract Deep (4000–6000 m) and ultra-deep burial (>6000 m) carbonate reservoirs are becoming important petroleum exploration targets of China and worldwide basin. Thermochemical sulfate reduction (TSR) may be pervasive in the deep and ultra-deep burial petroliferous carbonate strata associated with evaporite. However, there is still considerable confusion on the effect of TSR on reservoir quality. Petrography, geochemistry and fluid inclusion data from carbonate reservoirs of Tarim Basin were integrated to resolve the disagreement. Based on distribution of sulfur-bearing mineral, SO42− concentrations and SO42−/Cl− ratios in both formation water and fluid trapped in fluid inclusion, we propose that SO42− in formation water is likely major reactant involved in TSR reaction of North Slope, whereas coarsely diagenetic anhydride is likely major sulfate reactant involved in TSR reaction of East Burial Hill Belt. Silurian fracture-filling pyrite has δ34S values similar to those of Ordovician fracture-filling pyrite, H2S and sulfur, suggesting that TSR dissolved sulfate involved in (North Slope) may occur in a partly open system for H2S and CO2. However, TSR diagenetic anhydride involved in (East Burial Hill Belt) may occur in a closed diagenetic system. TSR in a partly open-system, associated with gas charge and flow of cross formational fluids, probably increased fluid pressure, and further transported H2S, CO2 and solute from dissolution through fracture. A closed system of Anhydrite-bearing strata seems to hinder transports of TSR-derived CO2 or bicarbonate, and result in precipitation of TSR calcite, pyrite and bitumen close to the TSR sites. In combination with petrographic observations, intense dissolution in North Slope have released more inorganic CO2 leading to TSR calcite and CO2 in the natural gas showing δ13C values much heavier relative to δ13C values of TSR calcites in East Burial Hill Belt as light as −13.4‰. TSR-induced dissolution of carbonate minerals during oil-dominated TSR may be related to the reaction of dolomite with anhydride and release of H+ due to pyrite precipitation, rather than new formed water during TSR. Similar to geological settings of Ordovician TSR, Anhydrite-poor Lower Cambrian dolostones underlying evaporites seals may thus be the most promising target for future exploration success in ultra-deep Cambrian reservoirs of Tarim Basin. The controversy about the effects of TSR on reservoir quality can partly be ascribed to differently geological settings where TSR occurred.
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thermochemical and bacterial sulfate reduction in the cambrian and lower ordovician carbonates in the tazhong area tarim basin nw china evidence from fluid inclusions c s and sr isotopic data
Geofluids, 2015Co-Authors: Lianqi Jia, Chunfang Cai, H Yang, Tiankai Wang, Baoshou Zhang, Lei Jiang, X TaoAbstract:Petrographic features, C, O, S, and Sr isotopes were determined, and fluid inclusions (FI) were analyzed on various stages of vug- and fracture-fillings from the Cambrian and Lower Ordovician reservoirs in the Tazhong area, Tarim basin, NW China. The aim was to assess the origin of pyrite and Anhydrite and the processes affecting sulfur during diagenesis of the carbonates. Pyrite from seven wells has δ34S values from −22‰ to +31‰. The pyrites with low δ34S values from −21.8‰ to −12.3‰ were found close to fracture-filling calcites with vapor-liquid double-phase aqueous fluid inclusions homogenization temperatures (FI-Th) from 55.7 to 73.2°C, salinities from 1.4wt% to 6.59wt% NaCl equiv and δ13C values from −2.3‰ to −14.2‰, indicating an origin from bacterial sulfate reduction by organic matter. Other sulfides with heavier δ34S values may have formed by thermochemical sulfate reduction (TSR) during two episodes. The earlier TSR in the Middle and Lower Cambrian resulted in pyrites and H2S having δ34S values from 30 to 33‰, close to those of bedded Anhydrite and oilfield water (approximately 34‰). The later TSR is represented by calcites with δ13C values as light as −17.7‰ and FI-Th of about 120–145°C, and pyrite and H2S with δ34S values close to those of the Upper Cambrian burial-diagenetic Anhydrite (between +14.8‰ and +22.6‰). The values of the Anhydrite are significantly lighter than contemporary seawater sulfates. This together with 87Sr/86Sr values of Anhydrite and TSR calcites from 0.7091 to 0.7125 suggests a source from the underlying Ediacaran seawater sulfate and detrital Sr contribution.