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Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In chemo-mechanical coupling of clays, chemical phenomena are likely to have a stronger influence on the mechanical behaviour and mechanical actions can modify the chemical behaviour. The understanding of these different phenomena, taking into account the coupled mechanisms, is essential in the context of the problem of the durability of structures and works built on polluted sites. Thus, the laboratory characterisation of the chemo-mechanical behaviour of a clay contaminated by light hydrocarbon pollutant (BTEX: benzene) was carried out. First in the absence of pollutants, i.e., by the presence of water only, then under the influence of the pollutant, all in two stages: with no external stress, then under imposed external stress. This study presents an experimental protocol based on a series of uniaxial consolidation tests, specific oedometric tests and direct shear strength, this tests performed under controlled saturation conditions and in the presence of organic contamination by benzene. All results confirm the influence of pollutants in different concentrations on the mechanical behaviour of the soil. They show a strong increase in compressibility and a significant increase in swelling, the soil becomes more cohesive, low friction and less elastic. Furthermore, the results show that external load forces play a major role in modifying the behaviour of clay. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sapropel hydroprocessing was carried out in ethanol, at 200 °C, using CoMo catalyst. • The organic matter conversion increases with an increase in the fraction of protein. • An increase of protein leads to a decrease of oxygen in liquid products. • Protein leads to nitrogen-containing compounds and hydrocarbons in liquid products. The effect of sapropel nature on the conversion of organic matter and composition of liquid products in catalytic hydroliquefaction was studied. It was shown that the maximum conversion is achieved for the samples in which the organic matter is represented mostly by protein residues. For phytogenic sapropels the conversion is much lower. Investigation of the composition of liquid products revealed that an increase in the fraction of protein component in liquid products of hydroliquefaction leads to a decrease in the amount of oxygen-containing compounds and an increase in the fraction of nitrogen-containing compounds and hydrocarbons. [ABSTRACT FROM AUTHOR]

The Ediacaran succession occurs at the southwestern slope of the East European Platform from the Black Sea to the Lublin-Podlasie Basin. It includes a black shale interval in Ukraine represented by the Kalus Beds which may have hydrocarbon source rock potential. Coeval organic-rich rocks are known to have sourced commercial accumulations of oil and gas in different parts of the world. In western Ukraine and NW Moldova, the thickness of the Kalus shales exceeds 90 m. These strata crop out locally near the border of the Ukrainian Shield and dip in the southwestern direction towards the Teisseyre-Tornquist zone, reaching the depths of over 4000 m. This paper presents a study of hydrocarbon source rock potential of the Kalus Beds and is based on the results of organic geochemical and mineralogical investigations. The organic-rich Kalus Beds are represented by clay-rich siltstone in which quartz (38-66%) and mica (8-19%) prevail over clay minerals. They also contain a significant amount of feldspar (4-11%) and chlorite (4-12%). The clay fraction is represented by illite, chlorite, kaolinite and illite-smectite. Mixed-layered clay minerals are distributed at burial depths of up to 150 m. Kaolinite occurs in a wider range of depths, but below 3800 m clay minerals are represented exclusively by chlorite and illite. Such a proportion of mineral components of the analysed beds and the grain size of quartz indicate their high brittleness and thus suitability for efficient hydraulic fracturing. The total organic carbon content in the Kalus shales varies between 0.1 and 0.89 wt%, exceeding 0.5 wt% in some parts of the study area, and thus these strata can be considered as a lowquality potential hydrocarbon source rock. The maturation level of the Kalus Beds clearly depends on the depth of burial. These rocks are immature till a depth of 100 m. Generation windows for oil and gas occur within depth ranges from 100 to 2200 m and from 2200 to 3800 m, respectively. At greater depths these rocks are overmature. In the main part of the study area, the organic-rich Kalus Beds have significant thickness and are matured to the level of oil and gas windows and hence might generate hydrocarbons and contribute to the development of the petroleum system in the region. [ABSTRACT FROM AUTHOR]

Numerical simulations of the burial and thermal history of the Mannar Basin using the GALO system for basin modeling make it possible to evaluate the change in the temperature and organic matter maturation in the source rocks of the basin and trace the variations in the rock temperature and maturity with distance from the axis of the ancient rift. Our analysis shows that organic matter of Jurassic rocks recovered by Wells Pearl 1 and Dorado North, located in a flank of the rift, occurs within the oil window (0.50 ≤ Ro ≤ 1.30%), whereas the maturity of these rocks in Wells Pseudo Mannar Deep and Barracuda, which are close to the rift axis, considerably exceeds maturity within this window. The probable Jurassic source rocks generate mainly heavy and light oil and a little gas in areas far from the rift axis, but these rocks generate mainly gas in the areas near the axis. The modeling shows that the thermal activation of the lithosphere of this basin in the Upper Cretaceous had a noticeable effect on the temperature and maturity of the rocks in areas close to the ancient rift axis (Pseudo Mannar Deep and Barracuda wells), but its effect is markedly reduced in areas remote from the rift axis (Wells Pearl 1 and Dorado North). [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Methodological bases and uniform standardization criteria of humic compounds as substances for drug products have not been developed yet. This is due to the structural complexity of humic compounds, the variety of ways to extract them from natural objects, the impossibility of using many classical methods of analytical chemistry to identify and quantify humic substances (HS), the lack of standard samples. The identification of humic acids (HA) in the aqueous sapropel extract (ASE) is identified after extracting from ASE by alkaline hydrolysis by the quantification method. After further precipitation with a concentrated sulfuric acid solution characteristic dark brown color is appeared. It was carried out the HA extraction from the sample of ASE, the precipitation of HA, the oxidation of HA and Mohr’s salt titration in accordance with the methodology developed on the basis of SSTU 7083:2009. It was determined that the total mass fraction of HA in the ASE sample was 83.8 mg/g± 0.12%. The methods of identification and quantification of the total mass of HA in ASE have been developed and validated. The ASE has been standardized. [ABSTRACT FROM AUTHOR]

Tight gas sandstone and volcanic gas reservoirs have received global attention in the energy arena for further exploration and exploitation attempts. Considering the Yingcheng Formation of Dehui fault depression in the Songliao Basin as an example, this study focused on the accumulation and distribution of natural gas reservoirs in volcanic area in a fault depression basin. Volcanic activities occurred in the Yingcheng Formation, which is distributed centrally in the northwest of the study area. During the sedimentation of the Yingcheng Formation, fan-delta, lacustrine, and nearshore subaqueous fan facies were deposited. The source rocks of the Yingcheng Formation have high abundance of organic matter mainly in type III at high-overmature stages, indicating favorable conditions for gas production. The porosity of volcanic reservoir is 3.0%-14.8%, the permeability is 0.0004 mD-2.52 mD, and the pore types are mainly secondary dissolved pores and fractures. Besides, the porosity of the tight sandstone reservoir is 0.5%-11.2%, and the permeability is 0.0008 mD-3.17 mD. The pore types are mainly interparticle pores, with a small proportion of intraparticle pores and microfractures. The intrusion of late volcanic magma provided sufficient heat for the thermal maturity progression of organic matter in Yingcheng Formation and promoted the generation of natural gas in large quantities. Volcanic rocks formed at the early and middle stages of volcanic activities occupied the sedimentary space and hindered the development of sedimentary sand bodies to a certain extent. However, volcanic rocks can become the seal to promote the formation of tight sandstone gas traps. Comparing tight sandstone reservoirs with volcanic ones, the latter are less affected by compaction; thus, their petrophysical properties do not vary much with depth, showing more homogeneous characteristics. The pyroclastic rocks influenced by volcanic activity and the secondary pores formed by dissolution in the later stages also provide reservoir space for gas accumulation. Ultimately, the tight sandstone and volcanic rocks in the study area form a complex gas reservoir system, which can become a reference for exploration and exploitation of natural gas in other petroliferous fault depressions that are affected by volcanisms. [ABSTRACT FROM AUTHOR]

Aloysia. triphylla (L, H, er.) Britton (Family Verbenaceae) is applied in nutritional and pharmacological purposes. Soil factors and climatic tensions are essential in the growth of the herbs. A. triphylla plants were planted in the University greenhouse (Zahedan) in March. Humic substances solutions were sprinkled onto the soil surrounding the root of the plant. This way of planting simultaneously was repeated in the Zahedan outskirts and Zarand area. In late June, the leaves of planted samples were collected and prepared for senescing through the hydro distillation method. After collecting leaves and be sprinkled with humic substances solution onto the root surrounding soil of the same plant, the leaves were picked up again in late September for oil extraction. Oil yields (w/w%) of the greenhouse's June samples were 0.45 and 0.48 for the blank and humic samples respectively. By analyzing oils, using GC & GC-MS techniques, 47 and 46 compounds were identified from the blank sample and humic sample oils, constituting 93.21% and 91.58% respectively. The higher percent of which: limonene, 1, 8-cineole, Z-citral, E-citral, bicylogermacrene, trans-caryophyllene, spanthenol compounds. Oxygenated terpenoids percentage in the humic sample oils varies between 43.70 and 60.16 of which 43.70 belongs to the oil of Zarand September humic sample (Sapropel) and 60.16 to the oil of the greenhouse's June humic sample (Sapropel). Oxygenated terpenoid compounds in September samples have decreased a fewer than those of June samples. These changes result from humic substances and climatic tensions. As a result, the flowering period is shortened and the oil quality has been optimized. [ABSTRACT FROM AUTHOR]

Lake sediments accumulate various pollutants and act as efficient natural archives suitable for reconstruction the environmental conditions of the past. In contrast to fairly good knowledge of mineral sediments in lakes of European and North America boreal lakes, Siberian lakes of the boreal zone remain quite poorly studied. In this work, two cores of lake sediments of the Ob River valley were investigated. Elemental analyses were carried out on the sediments, losses on ignition were determined, and the rate of sedimentation was measured from the activity of Pb-210 and Cs-137. According to the content of organic matter, bottom sediments belong to different types: clastic (Lake Inkino, located in the Ob River floodplain) and organogenic (Lake Shchuchie on the second terrace). The rate of sedimentation in Lake Shchuchie is several times higher than that in Lake Inkino. The sediments of Lake Inkino are similar in composition (including the pattern of rare earth elements) to the suspended particulate matter of the Ob River as well as to average detrital matter of the upper continental crust. Sediments of Lake Shchuchie (sapropels) are enriched in a number of heavy metals. Based on the elemental composition, signs of diagenetic processes and authigenic mineral formation were determined, such as accumulation of carbonates and the formation of manganese oxides and hydroxides. There is an enhanced recent input of Cr, Co, Cu, Zn, Cd, Sb, Pb, and Bi in the upper layers of sediments as a result of atmospheric anthropogenic pollutant deposition.

An understanding of how the coupled cycles of carbon, iron and sulfur in sediments respond to environmental change throughout Earth history requires the reconstruction of biogeochemical processes over a range of spatial and temporal scales. In this study, sediment cores from the southwestern Black Sea were analyzed to gain insight into past changes in biogeochemical processes with particular focus on the cycling of dissolved organic carbon (DOC). The sediment consists of Late Pleistocene deposits of iron oxide-rich and organic-poor lacustrine sediments, a Holocene sapropel layer deposited after the inflow of saline Mediterranean seawater about 9300 yr BP, and overlying recent marine sediments. The porewaters displayed high concentrations of DOC, acetate, dissolved iron and an extended depth interval over which sulfate and methane were both present. The historical fluctuations of the fluxes of carbon, sulfur and iron species at the seafloor that led to these present-day geochemical profiles, and which cannot be easily interpreted from the measured data alone, were hindcasted with a reaction-transport model. The model suggests that the inflow of Mediterranean seawater impacted the rain rate and reactivity of organic matter reaching the sediments, which shifted the sedimentary redox regimes throughout the Holocene that now are reflected on different lithology units. Organic matter in the sapropel layer is apparently the main source of modern-day accumulations of DOC and acetate, both of which probably sustained subsurface microbial activity throughout the post-glacial period. The ratio between DOC and dissolved inorganic carbon (DIC) flux to the bottom water decreased from ∼40% before the inflow of Mediterranean water to ∼2% at the present day. We suggest that the coexistence of methanogenesis and sulfate reduction was associated with sulfate-reducing bacteria and methanogens sharing common substrates of acetate and lactate and utilizing non-competitive substrates such as methylated compounds in the sapropel layer and in the bottom of modern marine deposits. Intense sulfur and iron cycling mainly took place in the organic-poor freshwater deposits, today characterized by high concentrations of dissolved iron and methane. In contrast to previous studies in similar environments, anaerobic oxidation of methane coupled to the reduction of ferric iron was negligible. The results have broad implications for coastal environments that are currently experiencing deoxygenation and seawater intrusion and also for understanding the role of DOC in the sedimentary carbon cycle. [ABSTRACT FROM AUTHOR]

China is a top world producer of coal resources with numerous coal‐rich basins country‐wide that also contain coalbed methane (CBM), an unconventional natural gas resource. Recent exploration of coal and CBM resources has also led to the discovery of rare, precious, and scattered metal minerals, including sandstone‐type U and Ga–Ge–Li. High‐grade and industrial‐value deposits have been discovered in the Ordos, Junggar, and other basins across China during exploration for coal resources. Application of coordinated exploration theories and techniques in multiple energy and coal‐associated ore deposits, such as coal and unconventional natural gas in coal, achieves efficient and practical exploration of natural resources. Based on the systematic study of accumulation and occurrence of coal and coal‐associated mineral resources in coal basins, the basic idea of coordinated exploration for coal and coal‐associated deposits is proposed, and multi‐targets and multi‐methods based on a coordinated exploration model of coal‐associated deposits is developed. Coordinated exploration expands the main exploration objective from coal seams to coal‐associated series, extending the exploration target from targeting coal only to coal‐associated deposits. Entrance times for exploration are decreased to realize coordinated exploration for coal, unconventional natural gas and syngenetic/associated mineral resources in coal by implementing a 'one‐time approach' —one time in and out of a coal seam to minimize disturbance and time needed for extraction. According to the differences of geological background in China's coal basins, four coordinated exploration model types, including co‐exploration of coal and coal‐associated unconventional natural gas, coal and solid minerals, coal and metal minerals, and coal with water resources are established. Other models discussed include a multi‐target coordinated exploration model for the combination of coal, coal‐associated gas, solid minerals, and metal minerals accordingly. The exploration techniques of coal and coal‐associated resources include regional geological investigation and research and synthetic application of other techniques including seismic surveys, drilling, logging, and geochemical exploration. Particularly, applying the 'multi‐purpose drill hole' or reworking coalfield drill holes into parameter wells, adding sample testing and logging wells, determining gas‐bearing layers by logging and gas content measurement, jointly measuring multiple logging parameters, sampling, and testing of coal‐strata help in the exploration and evaluation of coal resources, coal‐associated unconventional natural gas resources, and coal‐associated element minerals. Accordingly, a system of integrated Space–Air–Ground exploration techniques for coordinated exploration of coal and coal‐associated minerals is established. This includes high‐resolution, hyperspectral remote‐sensing technique, high‐precision geophysical exploration and fast, precise drilling, testing of experimental samples, as well as coordinated exploration and determination methods of multi‐target factors, multi‐exploration means, multi‐parameter configuration and optimization, big data fusions and interpretation techniques. In recent years, the application of this integrated system has brought significant breakthroughs in coal exploration in Inner Mongolia, Xinjiang and other provinces, discovering several large, ten‐billion‐ton coalfields, such as the Eastern Junggar and Tuha basins, and also in exploration and development of CBM from low‐rank coals in Fukang, Xinjiang, discovery the Daying U Deposit in Inner Mongolia, the Junggar Ultralarge Ga Deposit, Lincang, Yunnan, and the Wulantuga, Inner Mongolia, Ge‐bearing coal deposits, and the Pingshuo Ultralarge Li–Ge Deposit. [ABSTRACT FROM AUTHOR]

To date, studies for bioremediation of oil-polluted hypersaline soils have been neglected or limited to specific spots. Hence, in this study, ten samples of oil field soils in the Khuzestan province of Iran were collected to evaluate bioremediation's feasibility. These samples were analyzed for their physicochemical properties as well as the most probable number of total and hydrocarbon-degrading bacteria. Thirty-nine hydrocarbon-degrading bacteria were isolated from these soils over a 1-month incubation in an MSM medium enriched with diesel oil as the sole source of carbon. As revealed by 16S-rRNA analysis, the identified strains belonged to the genera Ochrobactrum, Microbacterium, and Bacillus with a high frequency of Ochrobactrum species. Additionally, by using degenerate primers, the third group of alkB gene was detected in Ochrobactrum and Microbacterium isolates through the touchdown nested PCR method for the first time. Ochrobactrum species possessing the alkB gene showed the highest population, and therefore, the highest adaptation to harsh environmental conditions. Most isolates showed outstanding results in the ability to grow with crude and diesel oil and tolerate high salt percentages, biosurfactant production, and emulsification activity, which are considered the most effective factors in bioremediation of such environments. Considering the soil analysis, limiting factors in bioremediation like available phosphorous, and the abundance of bacteria with remediation traits in these soils, these extremely polluted environments can be refined. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Oligocene succession of the Tikak Parbat Formation has prominent coal bearing horizons. The formation comprises of medium to coarse grained light coloured sandstone, clay and carbonaceous shale with four workable coal seams. Core samples from two wells has been studied with regards to organic matter content and type. Relatively high total organic carbon (TOC) contents are present (average 72.103 wt %) in coal; the hydrogen index (HI) values reach a maximum of 410 mg HC/g TOC, indicating presence of type III-II kerogen, and the organic matter is thermally immature (Tmax 428°C) in coal. The genetic potential have maximum yield of 246.53 mg/g, so the coal deposits could act as an excellent source rock for hydrocarbons if the burial depth is sufficient. Carbonaceous shale samples are at early mature stage (Tmax 438°C). Kerogen at this maturity level is within oil window and is capable of generating oil and thermogenic gas upon thermal cracking. The study highlights dense accumulation of reactive macerals (vitrinite + liptinite) and low concentration of inertinite. The empirically derived values for coal reveal a high conversion (>90%) and oil yield (>60%). [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil contamination by hydrocarbons due to oil spills has become a global concern and it has more implications in oil producing regions. Biostimulation is considered as one of the promising remediation techniques that can be adopted to enhance the rate of degradation of crude oil. The soil microbial consortia play a critical role in governing the biodegradation of total petroleum hydrocarbons (TPHs), in particular polycyclic aromatic hydrocarbons (PAHs). In this study, the degradation pattern of TPHs and PAHs of Kuwait soil biopiles was measured at three-month intervals. Then, the microbial consortium associated with oil degradation at each interval was revealed through 16S rRNA based next generation sequencing. Rapid degradation of TPHs and most of the PAHs was noticed at the first 3 months of biostimulation with a degradation rate of pyrene significantly higher compared to other PAHs counterparts. The taxonomic profiling of individual stages of remediation revealed that, biostimulation of the investigated soil favored the growth of Proteobacteria, Alphaprotobacteria, Chloroflexi, Chlorobi, and Acidobacteria groups. These findings provide a key step towards the restoration of oil-contaminated lands in the arid environment. [ABSTRACT FROM AUTHOR]

Structure, morphology, and composition of the gas for natural gas hydrates sampled in the Kedr-1 mud volcano (Lake Baikal) are studied. It is shown that all these hydrates have cubic structure II, and the hydrate‐bound gas contains about 14% of ethane (the rest is methane). One of the samples is a porous monolithic hydrate layer sandwiched between the layers of hydrate granules. The hydrate has similar structures and compositions in the layer and in the granules. As far as we know, no such morphology features of natural hydrates have been reported so far. Possible mechanisms underlying the formation of such objects are discussed. [ABSTRACT FROM AUTHOR]

This work investigates the feasibility of using frac‐packing techniques to complete wells in marine gas hydrate fields. It focuses on the long‐term well productivity under pseudo‐steady state flow conditions after the gas hydrate reservoir pressure drops to below the hydrate dissociation pressure within the well drainage area. The analytical model proposed by Shan et al. (J Energy Sci Eng, 2020, 8, 1247) for cross‐flow in the fractured region was modified in this study to include the horizontal radial flow in the non‐fractured region of the well drainage area. Methods were developed to predict the fracture geometry and to design proppant size distribution for formation sand/particle control. Sensitivity analyses with the model identified the fracture radius and permeability being the key factors affecting the productivity of frac‐packed wells. Well productivity was found to increase non‐linearly with fracture radius and permeability. The benefit of increasing fracture size drops due to the choking effect near the wellbore and pressure loss inside the fracture. The benefit of increasing fracture permeability diminishes when the fracture permeability is large due to the bottleneck of low reservoir permeability. Gas hydrate wells in the Shenhu area, northern South China Sea, can be elevated to commercial levels of greater than 10 MMscf per day with a proppant injection volume of 110 cubic feet during frac‐packing. Well productivity can be further increased by injecting higher proppant volume to enlarge fracture. This work presents a simple method for assessment of frac‐packing design to improve well productivity in marine gas hydrate reservoirs. [ABSTRACT FROM AUTHOR]

Saline lakes have developed worldwide throughout geological history and continue to develop, is important for understanding deep-time climate evolution, lake evolution and extinction, terrestrial ecosystem evolution, and organic carbon burial processes. The basic conditions required for the formation of saline lakes are a sufficient source of salt, an arid or semi-arid climate, and a closed or semi-closed lake environment. There are four mechanisms of lake basin salinization: (1) seawater-derived salinized lake, salt irons are provided by seawater; (2) Inland evaporative saline lakes, the land is the source of salt substances following strong evaporation; (3) Deep hydrothermal fluids-based saline lakes, high-salinity hydrothermal fluids enter the basin through faults; and (4) Any combination of the above mechanisms. During the evolution of saline lake, one or more can be the main salinization mechanism, and the primary mechanism may change with the evolution of salinization periods. Hydrological characteristics of saline lakes control biome development, biogeochemical processes, sediment deposition, and organic matter enrichment. Due to high productivity and reducing conditions, the salinized lake basin environment is conducive to the formation of organic rich source rocks and/or type I and II sapropelic organic matter with high hydrocarbon generation potential. Future studies should focus on evolutionary processes of deep-time saline lake development based on Earth System Science and interactions between spheres, ecological reconstruction and biogeochemical processes in saline lakes, sediments burial diagenesis and physico-chemical-microbiological processes. [ABSTRACT FROM AUTHOR]

The second member of the Funing Formation (E 1 f2) is a Paleocene lacustrine organic-rich shale and has been identified as a primary source rock for both conventional and unconventional oil and gas in East China. It is correlated with the Early Late Paleocene Event (ELPE), a significant temperature inflection point in the Paleocene. However, the impact of the ELPE on the lacustrine organic-rich sedimentation is still not well understood. This study pinpoints the ELPE in the lacustrine E 1 f2 shale of the Subei Basin, identifies the resultant marine incursions by biomarkers, correlates the ELPE, marine incursions, and the depositional process, and clarifies organic matter accumulation mechanisms in the E 1 f2 shale. The interval preceding the ELPE has relatively low organic matter content, having been deposited in an arid paleoclimate with saline water conditions and low productivity. Eukaryotes predominantly contributed to the organic matter accumulation. The ELPE is identified in the E 1 f2 shale by negative carbonate carbon and oxygen isotope excursions. Subsequently, increasing temperatures and rising global sea levels induced marine incursions into the Subei Basin, supported by the appearance of 24- n -propylcholestane and the C 30 /C 27-30 steranes ratio. The interval following the ELPE shows relatively high organic matter content and was deposited in an arid to semihumid-semiarid climate and a saline to brackish waterbody. Marine incursions likely introduced nutrients and enhanced lacustrine productivity, as indicated by the consistency between signals of marine invasion and bioavailable nutrient elements. Different origins contribute to organic matter accumulation at this stage, with prokaryotes being more dominant than eukaryotes. The E 1 f2 shale provides valuable insights into lacustrine organic-rich sedimentary processes and the responses of lacustrine systems to global events. • The depositional environment of the Paleogene lacustrine shale was reconstructed. • The lacustrine depositional process was correlated with a global climate event. • The impact of marine incursions on shale deposition was dissected. • Organic matter accumulation models in the Paleogene lacustrine shale were established. [ABSTRACT FROM AUTHOR]

[Display omitted] • Seafloor seepage oils are acquired by piston coring in the Beikang Basin, southern South China. • Sea (SCS). • Seafloor seepage oils are probably originated from coal-related source rocks. • Hydrocarbons at depths were expelled to the subseabed driven by fluid overpressure. • Oil seepage induces the reaction of AOM, which modifies geochemical signatures in subsurface sediments. • Oil seepage contains valuable information in enlightening hydrocarbons and hydrates exploration. Seafloor oil seepage, resulting from fluids migration from depth, provides valuable insights into the characteristics of potential source rocks and hydrocarbons. For the first time, seafloor seepage oils were obtained by piston coring in the Beikang Basin, southern South China Sea (SSCS). Based on integrated analysis of the seismic data, core sediments, porewater, headspace gas and heat flow, the geochemical characteristics of seafloor seepage oils and their geological implications were elucidated. Results indicate that deep-sourced hydrocarbons intruded into subsurface sediments via paleo-uplift-related faults, fluid seepage pipes and mixed with in-situ modern marine sediments. Biomarkers suggest the presence of both marine and terrestrial organic matter, as well as a diverse range of thermal maturity levels from immature to mature. The seafloor seepage oil was most likely originated from coal-related source rocks in the Oligocene-Lower Miocene. Deep hydrocarbons were expelled through fractures induced by hydrocarbon-generating overpressure, as well as source rock-connecting faults and finally accumulated atop the paleo-uplift beneath the T3 unconformity. The gradually increased fluid pressure ultimately leads to the fracturing of overlying caprocks, resulting in the formation of fluid seepage pipe and the occurrence of oil seepage on the seafloor. Seafloor oil seepage and the accompanied high methane flux caused biogeochemical process, elements cycling and shoaled the depth of sulfate-methane transition zone (SMTZ), which provides valuable information in indicating gas hydrates occurrence. This study offers significant geological and geochemical information to reveal potential origin of source rocks and hydrocarbons, particularly in the case of limited drilling wells in the SSCS. In addition, this study also advances the understanding of gas-bearing fluids activity and the coupling relationship between deep and shallow strata under a focused fluid seepage background. [ABSTRACT FROM AUTHOR]

Organic-rich deposits are valuable paleo-archives, recording significant paleoceanographic changes linked to past climate variations and marine deoxygenation events. The deposition of organic-rich sediments stops when bottom-water reventilation/oxygenation occurs. This impedes organic matter preservation, enabling macro and micro burrowing-organisms to recover and bioturbate the seafloor. In this sense, highly bioturbated sediments require particular attention when sampling is done for geochemical analyses, as sediments can be considerably mixed. While avoiding trace fossils during sampling for geochemical analyses is easy for large traces (e.g. Planolites, Thallasinoides, and Zoophycos), it becomes challenging for smaller and complex traces (< 0.5 cm), as is the case with Chondrites. Chondrites -producers have an opportunistic behavior, being one of the first organisms to colonize the seafloor after an anoxic event. As a result, Chondrites are commonly and sometimes abundantly found in the upper layers of organic-rich sediments, including sapropels and black shales. This study focuses on sapropel S7, which was deposited between ∼198.5 and 191.9 ka at the top of Eratosthenes Seamount and exhibits abundant Chondrites. For this sapropel, we demonstrated that Chondrites -producers can bioturbate significant volumes of organic-rich sediments (over 35%), introducing oxic/dysoxic material downward into anoxic sediments enriched in redox-sensitive trace metals and organic matter. This process can dilute up to 18% the original concentration of redox-sensitive trace metals (e.g. Mo, U and V). This dilution is especially important to consider when calculating trace metals and organic matter burial flux from bulk sediment data. Therefore, Chondrites -producers can play a crucial role in altering the sediment texture and distribution of minerals and organic matter at sub-cm scale, and may thus impact paleoenvironmental and paleoceanographic reconstructions based on geochemical signals. Furthermore, the subsequent redistribution of organic matter and redox-sensitive trace metals (including oligoelements) within the sediment can affect carbon and nutrient cycling, microbial activity, organic matter degradation in deep-marine sediments, and the overall sedimentary biogeochemistry. • Chondrites -producers influence organic matter and trace metals distribution. • Chondrites impact sedimentary biogeochemistry of organic-rich sediments. • Chondrites modified trace metals dynamics and redox conditions in sapropel S7. • Sapropel S7 can be divided in two sections with different oceanographic conditions. • Understanding Chondrites ' effect crucial for accurate paleoceanographic reconstructions. [ABSTRACT FROM AUTHOR]

High temperatures and rainy climate conditions result in a very low nutrient utilization rate during crop cultivation in tropical regions. To determine whether slow-release fertilizers could have a positive impact on the yield and quality of litchi, and the soil ecology of orchards while reducing chemical fertilizer application, a field plot experiment with two fertilizer types (chemical fertilizers and lignin-based slow-release fertilizers) combined with a 0 %, 15 % and 30 % reduction of fertilizer application rates was set up from 2018 to 2019. Subsequently, a demonstration trial with an optimum dose of slow-release fertilizers with chemical fertilizers was carried out from 2019 to 2020 in acidic soils. The results demonstrated that all treatments could maintain the yield of litchi between 11,825–13,056 kg/hm2 in 2018–2019. Furthermore, compared to conventional chemical fertilizer treatment, the treatment of lignin-based slow-release fertilizer application with a 15 % fertilizer reduction significantly reduced the concentration of alkaline nitrogen by 19.9 % and available phosphorus by 22.0 % at the 20–40 cm soil layer during the maturity period of litchi growth. The result of the demonstration trial in 2019–2020 further confirmed that a slow-release fertilizer, along with a 25 % reduction in fertilizer application, could maintain high levels of soil alkaline nitrogen and available potassium at the 0–20 cm soil layer without affecting soil bulk density, total soil porosity, and soil aeration. Moreover, the treatment of lignin-based slow-release fertilizer application with a 15 % fertilizer reduction significantly increased the relative abundance of Proteobacteria (1.21 times) and decreased the abundance of Firmicutes (0.81 times) compared to conventional fertilization treatment at the 0–20 cm soil layer. In contrast, it decreased the relative abundance of Firmicutes (0.67 times) and Proteobacteria (0.37 times) at the 20–40 cm soil layer. Meanwhile, the fertilizer application only affected the soil fungi richness but did not increase their diversity. Applying slow-release fertilizers can realize the goal of reducing chemical fertilizers and ensuring excellent litchi production in tropical acidic soils. [Display omitted] • Lignin-based slow-release fertilizers optimized soil microbial communities. • Lignin-based slow-release fertilizers maintained litchi yield and improved quality. • Use of slow-release fertilizers can reduce the nutrient inputs. • Slow-release fertilizers application may achieve litchi sustainable production. [ABSTRACT FROM AUTHOR]

The Island of Rhodes, located in the Eastern Mediterranean Sea, is affected by an active convergent plate boundary. In this context, marine sediments of Plio-Pleistocene age have been uplifted and are outcropping along the eastern coast of Rhodes. These archives provide an excellent opportunity to unravel the hydrological and climatic changes of the region during the late Pliocene. Our results provide new evidence for a more humid climate and an increased precipitation on the island during times of Northern Hemisphere summer insolation maxima and related sapropel formation in the Mediterranean deep sea. The periodic occurrence of eutrophic conditions at the shelf and upper slope off Rhodes is indicated by the recurrent dominance of eutrophic indicator species (of the genera Bolivina , Eubuliminella and Rectuvigerina), simultaneously with a decline in diversity and oligotrophic indicator species. These conditions resulted from higher primary productivity, triggered by local effects, such as enhanced precipitation and river run-off, which consequently favors the appearance of eutrophic taxa. The ∆δ13C records of the epibenthic foraminifera Cibicidoides pseudoungerianus and the shallow infaunal species Uvigerina peregrina indicate a slight productivity decrease towards younger times. • We investigated a Pliocene sediment section of the Lindos Bay Formation on Rhodes. • We found a recurrent and periodic dominance of eutrophic benthic foraminifera. • A periodic increase in nutrient supply and primary production is indicated. • The changes are likely triggered by enhanced local precipitation and river run-off. • The distinct periodicity suggests a relation to precession-induced climate changes. [ABSTRACT FROM AUTHOR]

The Pantanal is the most conserved biome in Brazil and among the last wild refuges in South America, but intensification of agriculture and other land use changes present challenges for protecting this exceptionally biodiverse wetland ecosystem. Recent studies have shed new light on the origins and biogeochemistry of a suite of >600 small saline-alkaline lakes in Nhecolândia, a floodplain setting located south of the Taquari River in south-central Pantanal. These soda lakes form a unique aquatic environment in Pantanal and nascent research on their geomicrobiology suggests that their biota may be analogous to early life, and extreme life in Earth's deep biosphere. We argue that the conservation of the soda lakes in the lower Nhecolândia region should be an important strategic component of any conservation plan that aims to mitigate the advance of unsustainable land-use change in the Pantanal. Soda lake conservation has important implications for the carbon cycle, as these landforms sequester carbon dioxide and transmit considerably lower concentrations of methane in comparison to macrophyte-rich freshwater lakes in the region. Further, minerals precipitated in the saline-alkaline lakes are leveraged for cattle consumption, and therefore the continued presence of the lakes is critical for allowing pantaneiro ranchers to pursue certified organic, sustainable beef production systems. Beyond protecting soda lakes and their surrounding forests (mata de cordilheiras) for food systems security, the conservation strategy would also allow further research of little studied extremophile biodiversity and biogeochemistry, with potential for biotechnological innovations attendant to UN Sustainable Development Goals.

Ocean deoxygenation is a rising threat to marine ecosystems and food resources under present climate warming conditions. Organic-rich sapropel layers deposited in the Mediterranean Sea provide a natural laboratory to study the processes that have controlled changes in seawater oxygen levels in the recent geological past. Our study is based on three sediment cores spanning the last 10 000 years and located on a bathymetric transect offshore from the western distributaries of the Nile delta. These cores are partly to continuously laminated in the sections recording sapropel S1, which is indicative of bottom-water anoxia above the western Nile deep-sea fan. We used a combination of microfacies analyses and inorganic and organic geochemical measurements to reconstruct changes in oxygenation conditions at seasonal to millennial timescales. Millimetre-thick laminations are composed of detrital, biogenic and chemogenic sublayers reflecting seasonal successions of sedimentation. Dark layers reflect the deposition of summer floods and two types of light layers correspond to autumn plankton blooms and authigenic carbonates formed in the water column during spring–early summer, respectively. The isotopic signature of the authigenic carbonates suggests permanent anoxic to euxinic bottom waters resulting in high levels of anaerobic remineralization of organic matter and highlights their potential to reconstruct seawater chemistry at times when benthic fauna was absent. Ratios of major elements combined with biomarkers of terrestrial and marine organic matter and redox-sensitive compounds allow changes in terrigenous input, primary productivity and past deoxygenation dynamics on millennial timescales to be tracked. Rapid fluctuations of oxygenation conditions in the upper 700 m water depth occurred above the Nile deep-sea fan between 10 and 6.5 ka BP, while deeper cores recorded more stable anoxic conditions. Synchronous changes in terrigenous input, primary productivity and past oxygenation dynamics after 6.5 ka BP show that runoff-driven eutrophication played a central role in rapid oxygenation changes in the south-eastern Levantine Basin. These findings are further supported by other regional records and reveal time-transgressive changes in oxygenation state driven by rapid changes in primary productivity during a period of long-term deep-water stagnation. [ABSTRACT FROM AUTHOR]

The aim of this paper was to study the microbiological stability of bio-based composite building materials, which are made using organic-rich lake sediments (further - sapropel) with lime and magnesium cement as binders and hemp shives as filler. The microbial stability properties of the obtained composite materials were investigated and compared to similar composites. Because of their high organic content, these materials are prone to biodegradation; therefore, they were coated with ALINA LIFE TM organoclay coating, which helps to extend the product life, reducing the rate of biodegradation compared to the biocides used in industry. The effect of the coating on the resistance to decay by the Aspergillus versicolor, Penicillium chrysogenum, Alternaria alternata, Cladosporium herbarum, Chaetomium sp. and Trichoderma asperellum fungi was investigated under different conditions: relative humidity modes of 75% and 99% at 20°C for 45 days and four months. The results indicated that the composites made of sapropel and lime have similar microbial stability properties as lime and magnesium cement binder composite materials. ALINA LIFE TM organoclay coating showed advanced resistance to biodegradation; sapropel-lime composites have shown several good properties that make them suitable to be considered for use in the construction material industry. [ABSTRACT FROM AUTHOR]

• OMZs developed in intermediate water of SE Levantine basin during early Holocene. • Oxygen status of overlying water defined by benthic forams, Fe speciation and RSTM. • Overlying water was anoxic non-sulphidic not euxinic as found in deep water at that time. • SEDEX P showed P was recycled into overlying water and fixed as apatite in sediment. • Speculated that modern OMZs possibly adjacent to major rivers could develop similarly. Oxygen Minimum Zones (OMZs) are expanding in modern oceans due to anthropogenically-driven climate and environmental change. In the Eastern Mediterranean Sea (EMS), OMZs developed in the early Holocene as a result of decreased intermediate water ventilation, increasing temperature, and increased Nile discharge and primary productivity. Here, we report benthic foraminiferal numbers (BFN) and species abundances, together with redox-sensitive trace metals (RSTM), and iron and phosphorus speciation from two sediment cores sampled at intermediate depths (1200 and 1430 m) from the SE Levantine shelf. The main aim of our study is to better understand the sequence of redox changes during sapropel S1 deposition caused by biogeochemical processes affecting the sapropel intermediate water mass. The use of benthic foraminifera indices (diversity and oxygen) together with iron speciation and RSTM (V, Mo and U) enables detailed description of the changing oxygen/redox status of the overlying water. Prior to sapropel S1 deposition at ∼10.2 ka BP, RSTM suggest that the overlying water was well oxygenated, but benthic foraminifera numbers (BFN) suggest that oxygen levels had already begun to decrease. There was then a pulse of increased export carbon from the enlarged Nile flood plume, as shown by increased BFN at the beginning of sapropel S1. Shortly after, RSTM and Fe-S systematics suggest that the water column transitioned from dysoxic to anoxic, non-sulfidic. Anoxic conditions then persisted at 1200 m depth, but RSTM and benthic foraminifera indices suggest that deeper waters at 1430 m were more likely dysoxic, until the 8.2 ka BP global cooling event. The benthic foraminifera and inorganic redox proxies then suggest a second period of anoxic, non-sulfidic conditions, with a gradual return to well ventilated waters at the end of sapropel deposition at ∼6 ka BP. There was enhanced burial of authigenic P throughout sapropel deposition, derived from the deposition and subsequent release of organic-P and iron bound-P during diagenesis. Phosphorus recycling from the sediment and in the overlying water column added reactive P to these mid-depth waters, a process which has the potential to result in a positive feedback in systems where such waters are upwelled into the photic zone. The past EMS thus represents a template which can be used to predict biogeochemical changes in settings that evolve towards anoxic, non sulfidic conditions, which may occur in some areas as modern climate and environment change causes the continued expansion of modern OMZs and hypoxic areas adjacent to modern major rivers. [ABSTRACT FROM AUTHOR]

At the beginning of the experiment, the weight of weekly cockerels of the Hisex White egg cross (n = 90) was 64.6 ± 0.47 g. At the age of one week old, 3 groups (30 birds in each group) were formed. They received complete feed. The first group served as a control. The chickens of the second and third groups received combined fodder, in which 3% and 5% of the feed weight was replaced with dry sapropel. The dry sapropel (3% of the daily feed weight) increased the activity of casein-lytic and hemoglobin-lytic peptidases in the chyme by 1.5 (P<0.05), in large intestine mucosa by 1.3 (P<0.05) and in small intestine mucosa by 1.7 times (P<0.01) compared with the control. The increase of sapropel concentration in feed up to 5% did not lead to a further increase in the activity of peptidases. The activity of peptidases were minimal at pH 5 and pH 12 and reached maximal at pH 7-8. The optimal dose of dry sapropel introduced into the diet of chickens to that stimulated the digestive processes is 3% of the mass of feed. [ABSTRACT FROM AUTHOR]

Soil bacteria rank among the most diverse groups of organisms on Earth and actively impact global processes of carbon cycling, especially in the emission of greenhouse gases like methane, CO2 and higher gaseous hydrocarbons. An abundant group of soil bacteria are the mycobacteria, which colonize various terrestrial, marine and anthropogenic environments due to their impermeable cell envelope that contains remarkable lipids. These bacteria have been found to be highly abundant at petroleum and gas seep areas, where they might utilize the released hydrocarbons. However, the function and the lipid biomarker inventory of these soil mycobacteria are poorly studied. Here, soils from the Fuoco di Censo seep, an everlasting fire (gas seep) in Sicily, Italy, were investigated for the presence of mycobacteria via 16S rRNA gene sequencing and fatty acid profiling. The soils contained high relative abundances (up to 34 % of reads assigned) of mycobacteria, phylogenetically close to the Mycobacterium simiae complex and more distant from the well-studied M. tuberculosis and hydrocarbon-utilizing M. paraffinicum. The soils showed decreasing abundances of mycocerosic acids (MAs), fatty acids unique for mycobacteria, with increasing distance from the seep. The major MAs at this seep were tentatively identified as 2,4,6,8-tetramethyl tetracosanoic acid and 2,4,6,8,10-pentamethyl hexacosanoic acid. Unusual MAs with mid-chain methyl branches at positions C-12 and C-16 (i.e., 2,12-dimethyl eicosanoic acid and 2,4,6,8,16-pentamethyl tetracosanoic acid) were also present. The molecular structures of the Fuoco di Censo MAs are different from those of the well-studied mycobacteria like M. tuberculosis or M. bovis and have relatively δ13C -depleted values (-38 ‰ to -48 ‰), suggesting a direct or indirect utilization of the released seep gases like methane or ethane. The structurally unique MAs in combination with their depleted δ13C values identified at the Fuoco di Censo seep offer a new tool to study the role of soil mycobacteria as hydrocarbon gas consumers in the carbon cycle. [ABSTRACT FROM AUTHOR]

Volcanic activity was quite frequent during the deposition of the Late Carboniferous Ha'erjiawu Formation in the Santanghu Basin. The petrology and organic and inorganic geochemical indicators were used to investigate hydrocarbon potential, paleoenvironmental conditions and organic matter enrichment of the mudstones. The results show that the oil generation capacity of the Ha'erjiawu Formation mudstones, which has abundant oil-prone organic matter (Type II kerogen with hydrogen index values mainly ranging from 250 to 550 mg HC/g TOC) in mature stage (Tmax values mainly ranging from 435 to 450 °C), is considerable. The Ha'erjiawu Formation was deposited in a dysoxic, freshwater-mildly brackish, and warm-humid environment. During its deposition, the Ha'erjiawu Formation received hydrothermal inputs. The volcanic hydrothermal activities played an important role in the organic matter enrichment. In addition, the total organic carbon (TOC) is significantly positively correlated with the felsic mineral content, but it is negatively correlated with the carbonate mineral content and C27/C29 ratios, indicating that terrigenous organic matter input also contributed to the primary productivity in the surface water. Therefore, the formation of the high-quality source rocks in the Ha'erjiawu Formation was jointly affected by the hydrothermal activity and the terrigenous organic matter input. [ABSTRACT FROM AUTHOR]

The results of studies of nickel-containing mono- and bimetallic catalysts deposited on carbon-mineral materials obtained on the basis of sapropel are reported. The effect of the chemical composition and acid treatment of the support on the physicochemical characteristics and properties of catalysts in the liquid-phase hydrogenation of nitrobenzene is shown. It was found that acid treatment of carbon-mineral supports leads to an increase in the activity of catalysts in the hydrogenation reaction due to an increase in the specific surface area (while maintaining the average pore size), the formation of acid sites on the support surface, and the formation of highly dispersed particles of supported nickel. [ABSTRACT FROM AUTHOR]

The Barents Sea is a typical example of a multiple sourced hydrocarbon system, with several gas and oil fields. Previous studies have suggested a gas and oil-prone character of the source rocks, but a lack of success in oil discoveries characterizes this area. In this work, the geochemical characterization of source rocks using well data from six exploration wells in the south-western part of the Barents Sea is presented. We studied the Upper Jurassic-Lower Cretaceous Knurr, Hekkingen and Fuglen Fms. mainly formed by shales and mudstones. Here, the Passey's method is applied to characterize the geochemical properties and organic matter of these formations by estimating total organic carbon content (TOC), the quantity of thermally generated hydrocarbons (S2), and hydrogen index (HI). Shale volume was also estimated to check the reliability of the calculated parameters. High shale volume values were found in all the formations, which are generally around 0.8 (volume fraction), indicating a predominance of shaly/muddy lithologies. However, some interbedded sandstones and siltstones are present, together with thinner dolomite and limestone layers. Our results show that Upper Jurassic source rocks such as Knurr Fm., which are often not object of geochemical studies, are mature and characterized by good organic carbon content. Good and very good organic carbon content are measured in the Fuglen and Hekkingen Fms., respectively. The hydrogen index suggests that all the source rocks are mixed gas-oil prone, with the Fuglen Fm. standing out as the most gas-prone between the studied formations. This study demonstrates that the Passey's method can be an alternative to infer geological information when geochemical data are not available. [ABSTRACT FROM AUTHOR]

Sapropel hydroliquefaction in supercritical ethanol at 260°С and a pressure of 18 MPa in the presence of СоМо/Al2O3 catalyst was studied. The maximal conversion of the sapropel organic matter (~76%) in supercritical ethanol is reached when adding gaseous hydrogen and a catalyst. The process is accompanied by removal of nitrogen, oxygen, and sulfur and by an increase in the hydrogen content of the liquid products. As shown by gas chromatography–mass spectrometry and IR spectroscopy, the liquid products of sapropel conversion in supercritical ethanol consist mainly of esters (41.8–46.5%) and alkyl derivatives of phenol (18.6–21.6%). [ABSTRACT FROM AUTHOR]

The Danish Central Graben, North Sea, is a mature oil‐ and gas‐producing basin in which the principal source rocks are the Upper Jurassic – lowermost Cretaceous marine shales of the Farsund Formation (Kimmeridge Clay Formation equivalent), with possible additional potential in the directly underlying Lola Formation. This study investigates the initial source rock potential of the basin by evaluating the original (back‐calculated) source rock properties (TOCo, S2o, HIo) of the shales in the Farsund and Lola Formations within a temporal and spatial framework. About 4800 samples from 81 wells regionally distributed in the Danish Central Graben were included in the study. Samples for source rock analysis were in general collected with varying sampling density from the entire shale section. The shale section has been divided into seven units (referred to as pre‐FSU1 to FSU6; FSU: Farsund Seismic Unit) which are delineated by mappable, regional‐scale seismic markers. For the pre‐FSU1 and FSU2–FSU6 units, the number of available samples ranged from 608 to 1145, while 433 samples were available for FSU1. Good source rock quality varies through space and time and reflects both the structural development of the basin and the effects of the Late Jurassic transgression, with primary kitchen areas developing in the Tail End Graben, Feda Graben, Gertrud Graben and the Rosa Basin. The source rock quality of the shales increases gradually through time and reaches a maximum in FSU6 which includes the "hot shales" of the Bo Member. The maximum source rock quality appears to correspond to an original Hydrogen Index (HIo) of approximately 675 mg HC/g TOC. The proportion of oil‐prone samples per unit (with HIo >350 mg HC/g TOC) ranges from 7 to 11% in the pre‐FSU1 to FSU2 units (Lower Kimmeridgian – Lower Volgian), increasing to 18 – 22% in FSU3 and FSU4/FSU5 (Lower Volgian – Middle Volgian), and reaching a maximum of 53% in FSU6 (Upper Volgian – Ryazanian). FSU6 is the most prolific oil‐prone source rock interval, but the presence of oil‐prone intervals in older and deeper parts of the shale succession is important for assessing the generation potential of the Upper Jurassic petroleum system. The breakdown of the Upper Jurassic – lowermost Cretaceous shale section into mappable seismic units with assigned original source rock properties will contribute to a considerably improved understanding of the temporal and spatial distributions of source rock quality in the Danish Central Graben. [ABSTRACT FROM AUTHOR]

The Silurian Akkas Formation has been reported and described only in the subsurface of western Iraq. The formation is divided into the lower Hoseiba Member, which contains two high‐TOC "hot" shale intervals that together are around 60 m thick, and the overlying Qaim Member that is composed of lower‐TOC "cold" shales. This study investigates the source rock potential of Akkas Formation shales from the Akkas‐1and Akkas‐3 wells in western Iraq and assesses the relationship between their mineral and elemental contents and their redox depositional conditions and thermal maturity. Twenty‐six shale samples from both members of the Akkas Formation from the Akkas‐1and Akkas‐3 wells were analysed. The results showed that the upper, ~20 m thick"hot" shale interval in the lower Hoseiba Member has good source rock characteristics with an average TOC content of 5.5 wt% and a mean Rock‐Eval S2 of 10 kg/tonne. Taken together, the two "hot" shale intervals and the intervening "cold" shale of the Hoseiba Member are ~125‐150 m thick and have an average TOC of 3.3 wt% and mean S2 of 6.2 kg/tonne. The samples from the Hoseiba Member contain mixed Type II / III or Type III kerogen with an HI of up to 296 mgS2/gTOC. Visual organic‐matter analysis showed that the samples contain dark brown, opaque amorphous organic matter with minor amounts of vitrinite‐like and algal (Tasmanites) material. Pyrolysis – gas chromatography undertaken on a single sample indicated a mature (or higher) algal‐dominated Type II kerogen. High spore and acritarch colour index values and weak or absent fluorescence similarly suggest that the lower part of the Akkas Formation is late mature to early post‐mature for oil generation. "Cold" shales from the Qaim Member in the Akkas‐3 well may locally have good source rock potential, while samples from the upper part of the Qaim Member from the Akkas‐1 well have little source rock potential. Varied results from this interval may reflect source rock heterogeneity and limited sample coverage. Mineralogically, all the shale samples studied were dominated by clay minerals – illite and kaolinite with minor amounts of chlorite and illite mixed layers. Non‐clay minerals included quartz, carbonates, feldspars and pyrite along with rare apatite and anatase. Palaeoredox proxies confirmed the general link between anoxia and "hot" shale deposition; however, there was no clear relationship between TOC and U suggesting that another carrier of U could be present. Rare Earth Element (REE) contents suggested a slight change in sediment provenance during the deposition of the Akkas Formation. The presence of common micropores and fractures identified under SEM indicates that these shales could become potential unconventional reservoirs following hydraulic fracturing. Evidence for the dissolution of carbonate minerals was present along fractures, suggesting the possible passage of diagenetic fluids. Palynological analysis combined with existing graptolite studies support a Wenlock ‐ Pridoli/Ludlow age for the Akkas "hot"shales. This is younger than many other regional "hot shale" age estimates and warrants further detailed investigation. [ABSTRACT FROM AUTHOR]

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Despite peloids' acknowledged therapeutic and cosmetic potential, there remains a limited understanding of their microbial diversity and dynamics, especially concerning beneficial and non-beneficial microorganisms under different heating conditions. Our study employs both cultivation and metagenomic methods to assess the microbiota of peloids, focusing on lake sapropel and peat under heating conditions recommended for external application and safety assurance. By applying microbial indicators specified in national regulatory documents, we found that all peloids reached thresholds for sulphite-reducing clostridia and colony-forming units. Each peloid exhibited a distinctive bacterial composition based on metagenomic analysis, and temperature-induced changes were observed in microbial diversity. We identified beneficial bacteria potentially contributing to the therapeutic properties of peloids. However, the same peloids indicated the presence of bacteria of human faecal origin, with a notably higher abundance of Escherichia coli , pointing to a potential source of contamination. Unfortunately, it remains unclear at which stage this contamination entered the peloids. The findings underscore the importance of monitoring and controlling microbial aspects in peloid applications, emphasising the need for measures to prevent and address contamination during their preparation and application processes.

Development trends need the necessity for wider use of the local resources and available natural materials are one of the priorities around the world. Freshwater sapropel is a common material in the water basement of the lakes, but still not sufficiently explored. The main goal of the project to start detailed and systematic research on the medical properties of sapropel to be obtained in Latvia, promote its scientifically based use in balneology, develop new medical procedures and services, and promote development of new exportable products. The results include the survey, sampling depths, and processing, evaluation of external signs, physical, chemical, and biochemical parameters, and evaluation of microbiological indicators. Active components from the sapropel samples extracted using the alkaline method. Sapropel extracts were characterized by organic carbon content, humic and fulvic acid concentrations, total phenolic content, trace metal and pesticide concentrations, total antioxidant status, and microbiological flora. Summarizing the article's main findings it was concluded that Latvian freshwater sapropel can be used as raw material for obtaining sapropel extract and use it in the preparation of pharmaceuticals and promote the development of new exportable products and services. [ABSTRACT FROM AUTHOR]

The distribution and geochemical significance of dibenzofurans, phenyldibenzofurans and benzo[b]napthofurans in source rocks from Niger Delta basin, Nigeria, were investigated by Rock–Eval pyrolysis and gas chromatography-mass spectrometry (GC–MS). The data obtained from the source rocks evaluation showed that the rock samples contained type II/III kerogen capable of generating oil and gas and were within immature to early mature stage. The relative abundance of the C0-, C1- and C2-dibenzofurans range from 1.75% to 29.82%, 27.60% to 40.52% and 29.66% to 68.89%, respectively. The dibenzofurans were dominated by C2-dibenzofurans. Among the C1-dibenzofurans, 2-+3-methyldibenzofuran was the most abundant in the rock samples while 1-methyldibenzofuran appeared to be the least. The relative abundance of benzo[b]naphtho[1,2-d]furan ([1,2]BNF), benzo[b]naphtha[2,1-d]furan ([2,1]BNF) and benzo[b]naphtha[2,3-d]furan ([2,3]BNF) in the rock extracts range from 12.01% to 52.58%, 32.61% to 75.21% and 10.27% to 52.43%. The wide range of values recorded for the three isomers of benzo[b]napthofurans in the samples suggest source rocks formed from mixed organic matter. Among the phenyldibenzofuran isomers, 4-phenyldibenzofuran was the most abundant while 1-phenyldibenzofuran was the least. Phenyldibenzofuran ratio-1 (PhFR-1) and phenyldibenzofuran ratio-2 (PhFR-2) values range from 0.13 to 1.20 and 0.11 to 2.11, respectively. The results showed that the relative abundance of PhFR-1 and PhFR-2 increase gradually with increasing burial depth and maturity (VR0 ≤ 0.77%, MPI-1 ≤ 0.62, Tmax ≤ 443 °C), and have a good correlations with calculated vitrinite reflectance, MPI-1 and maximum Temperature (Tmax). This range of values suggested immature to early mature source rocks. The source rocks were found to have shale and coal lithologies and deposited in a lacustrine/fluvial/deltaic settings within immature to early mature stages based on the distribution of dibenzofurans, phenyldibenzofurans and benzo[b]naphthofurans in the source rocks. This study showed that dibenzofurans, phenyldibenzofurans and benzo[b]naphthofurans were effective in determining the origin, depositional environment and thermal maturity of source rocks in Niger Delta basin, Nigeria. [ABSTRACT FROM AUTHOR]

This research aims to conduct source rock characterization on the Narimba Formation in the Bass Basin, Australia, which is made of mostly sandstone, shale and coal. The geochemical characteristics and depositional environments have been investigated through a variety of data such as rock–eval pyrolysis, TOC, organic petrography and biomarkers. Total organic carbon (TOC) values indicated good to excellent organic richness with values ranging from 1.1 to 79.2%. Kerogen typing of the examined samples from the Narimba Formation indicates that the formation contains organic matter capable of generating kerogen Type-III, Type-II-III and Type-II which is gas prone, oil–gas prone and oil prone, respectively. Pyrolysis maturity parameters (Tmax, PI), in combination with vitrinite reflectance and some biomarkers, all confirm that all samples are at early mature to mature and are in the oil and wet gas windows. The biomarkers data (the isoprenoids (Pr/Ph), CPI, isoprenoids/n-alkanes distribution (Pr/nC17 and Ph/nC18), in addition to the regular sterane biomarkers (C27, C28 and C29) are mainly used to evaluate the paleodepositional environment, maturity and biodegradation. It has been interpreted that the Narimba Formation was found to be deposited in non-marine (oxygen-rich) depositional environment with a dominance of terrestrial plant sources. All the analyzed samples show clear indication to be considered at the early mature to mature oil window with some indication of biodegradation. [ABSTRACT FROM AUTHOR]

The Patti Formation which consists of sandstone and shale offers the best potential source beds in the Bida Basin. This inland basin is one of the basins currently being tested for hydrocarbon prospectivity in Nigeria. Fresh samples of shale from Agbaja borehole, Ahoko quarry and Geheku road cut were analysed using organic geochemical and palynological techniques to unravel their age, paleoecology, palynofacies and source bed hydrocarbon potential. Palynological data suggest Maastrichtian age for the sediments based on the abundance of microfloral assemblage; Retidiporites magdalenensis, Echitriporites trianguliformis and Buttinia andreevi. Dinocysts belonging to the Spiniferites, Deflandrea and Dinogymnium genera from some of the analysed intervals are indicative of freshwater swamp and normal sea conditions. Palynological evidence further suggests mangrove paleovegetation and humid climate. Relatively high total organic carbon TOC (0.77–8.95 wt%) was obtained for the shales which implies substantial concentration of organic matter in the source beds. Hydrocarbon source rock potential ranges from 0.19 to 0.70 mgHC/g.rock except for a certain source rock interval in the Agbaja borehole with high yield of 25.18 mgHC/g.rock. This interval also presents exceptionally high HI of 274 mgHC/g.TOC and moderate amount of amorphous organic matter. The data suggests that in spite of the favourable organic matter quantity, the thermal maturity is low as indicated by vitrinite reflectance and Tmax (0.46 to 0.48 Ro% and 413 to 475 °C, respectively). The hydrocarbon extracts show abundance of odd number alkanes C27–C33, low sterane/hopane ratio and Pr/Ph > 2. We conclude that the source rocks were terrestrially derived under oxic condition and dominated by type III kerogen. Type II organic matter with oil and gas potential is a possibility in Agbaja area of Bida Basin. Thermal maturity is low and little, or no hydrocarbon has been generated from the source rocks. [ABSTRACT FROM AUTHOR]

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