Platform Area Research Articles

Top seal assessment of Drake Formation shales for CO2 storage in the Horda Platform area, offshore Norway

Evaluating top seal integrity is crucial for successful subsurface CO2 storage. Caprock shale geomechanical properties are complex and influenced by various parameters and processes. It is challenging to understand the role of various factors affecting the geomechanical properties; therefore, an integrated approach is required to evaluate top seal shales. In this study, we investigated the caprock properties of the Early Jurassic shaly Drake Formation overlying the reservoir sandstones of Early Jurassic Cook and Johansen formations. The study area is the potential CO2 storage site Aurora (the Longship CCS project), located in the Horda Platform area, offshore Norway. Based on lithological variations, the Drake Formation is subdivided into upper and lower Drake units. Variations of the geomechanical properties are investigated using wireline logs from 50 exploration wells, two 3D seismic cubes, and several 2D seismic lines. Elastic property-based brittleness indices of the Drake Formation caprock shales are evaluated to identify possible top seal quality. Moreover, seismic attributes and gas leakage scenarios are investigated qualitatively to assess the possibility of injected CO2 escaping from the reservoir. Low brittleness indices value of the Drake Formation shale near the Aurora injection site indicated that the seal rock might diffuse the injection-related stress change and act as an effective top seal. Based on the integrated qualitative assessment, it is likely that the Drake caprock shale will be acted as an effective top seal in and around the Aurora storage site. However, due to the complex nature of caprock shales, we recommend field-scale numerical simulation to evaluate the injection-induced stress-strain effect.

Multi-Scale Natural Fracture Prediction in Continental Shale Oil Reservoirs: A Case Study of the Fengcheng Formation in the Mahu Sag, Junggar Basin, China

Natural fractures in continental shale oil reservoirs of the Fengcheng Formation in the Mahu Sag show multi-scale characteristics, which leads to complex seismic responses and difficult identification. In order to establish fracture prediction models with good performance in these reservoirs, this study uses seismic attributes such as post-stack coherence, curvature, likelihood, and pre-stack AVAz to predict the multi-scale fractures, including main-secondary faults, large-scale fractures, and medium-small scale fractures in continental shale oil reservoirs. The final prediction results are superimposed on the plane to clarify the multi-scale fracture distribution law of the Fengcheng Formation in the Mahu Sag. Seismic prediction results show that natural fractures in the upper sweet spot of the Fengcheng Formation are more developed, especially in the northern and central platform areas, and they are mainly near E-W strikes. With the increase of the primary-secondary fault distance, the fracture density gradually decreases. Natural fractures obtained by seismic prediction are consistent with the fractures interpreted by image logs, which can be used to effectively predict fractures for continental shale oil reservoirs in the Mahu Sag of the Junggar Basin and other areas with a similar geological background.

Impedimetric detection of miRNA biomarkers using paper-based electrodes modified with bulk crystals or nanosheets of molybdenum disulfide

Paper-based electrodes modified with molybdenum disulfide (MoS2) in the form of bulk crystals or exfoliated nanosheets were developed and used as a biosensing platform for the impedimetric detection of miRNAs (miRNA-155 and miRNA-21) related to early diagnosis of lung cancer. For this purpose, MoS2 crystals or nanosheets were used for the modification of the working electrode area of paper-based platform for the first time in this study. The proposed assay offers sensitive and selective detection of microRNAs by electrochemical impedance spectroscopy (EIS) technique. The entire assay, both the electrode modification and the miRNA detection being completed in 30min and a single sample droplet (5μL) was enough to cover working electrode area which enabled analysis in low sample volumes. The limits of detection (LOD) for miRNA-21 and miRNA-155 were calculated both in buffer and fetal bovine serum media. It is found that the LOD is varying between 1 and 200ng/mL. In comparison to nanosheets, a larger electroactive surface area was obtained with bulk MoS2 resulting in lower LOD values on miRNA detection. The paper-based electrodes showed high specificity towards their target sequences. Moreover, they effectively discriminated single base mismatched non-target sequences. The advantages of these MoS2 paper based electrodes include high sensitivity, and low-cost provide great potential for improved monitoring of miRNA biomarkers even in artificial serum media.

Influence of Depositional and Diagenetic Processes on Caprock Properties of CO2 Storage Sites in the Northern North Sea, Offshore Norway

Characterization of caprock shale is critical in CO2 storage site evaluation because the caprock shale acts as a barrier for the injected buoyant CO2 plume. The properties of shales are complex and influenced by various processes; hence, it is challenging to evaluate the caprock quality. An integrated approach is therefore necessary for assessing seal integrity. In this study, we investigated the caprock properties of the Lower Jurassic Drake Formation shales from the proposed CO2 storage site Aurora (the Longship/Northern Lights CCS project), located in the Horda Platform area, offshore Norway. Wireline logs from 50 exploration wells, various 2D seismic lines, and two 3D seismic cubes were used to investigate the variations of the caprock properties. The Drake Formation was subdivided into upper and lower Drake units based on the lithological variations observed. Exhumation and thermal gradient influencing the caprock properties were also analyzed. Moreover, rock physics diagnostics were carried out, and caprock property maps were generated using the average log values to characterize the Drake Formation shales. In addiiton, pre-stack seismic-inverted properties and post-stack seismic attributes were assessed and compared to the wireline log-based analysis. The sediment source controlled at 61° N significantly influenced the depositional environment of the studied area, which later influenced the diagenetic processes and had various caprock properties. The upper and lower Drake units represent similar geomechanical properties in the Aurora area, irrespective of significant lithological variations. The Drake Formation caprock shale near the injection site shows less-ductile to less-brittle brittleness values. Based on the caprock thickness and shaliness in the Aurora injection site, Drake Formation shale might act as an effective top seal. However, the effect of injection-induced pressure changes on caprock integrity needs to be evaluated.

Depositional trends and reservoir geometries of the Early Cretaceous Lower Goru Formation in Lower Indus Basin, Pakistan: evidence from sequence stratigraphy

Lower Goru sand intervals of Early Cretaceous age are proven reservoirs in the Lower Indus Platform area. The delineation of reservoir geometries is of utmost importance while searching for stratigraphic and combination traps in clastic reservoirs. The data of ten wells and two 2D seismic lines from the northern part of the Lower Indus Basin are incorporated in this study. These reservoir intervals of the Lower Goru Formation are correlated in a third-order sequence stratigraphic framework to understand the depositional architecture and reservoir geometries. The Lower Goru Formation was deposited in westerly prograding river-dominated deltas developed by river system drained through the Indian Shield from east and south-east during Cretaceous time. Due to auto-cyclic switching of river distributaries, different lobes might have formed which if identified can point out the possible locations and configurations of stratigraphic and combination traps in this highly prospective area of Lower Indus Basin. The Lower Goru Formation (Barremian to Cenomanian) consists of one full second-order sequence of 20 Ma duration, having all the three fundamental system tracts in which eleven sequences of the third order, i.e. LG-1 to LG-11, were interpreted. Proven reservoir intervals of the Lower Goru Formation are concentrated in various third-order lowstand system tracts. The net sand and porosity maps of lowstand system tracts, gross depositional map and depositional cross section of the Lower Goru Formation point out the potential sites of good sandstone reservoirs and hint at the possible sand-body geometries.

Effects of Porphyromonas gingivalis injected through tail vein on the expressions of biomarkers in neural stem cells and neurons of wild-type rats hippocampus

Objectives: To study the effects of Porphyromonas gingivalis (Pg) injected through tail vein on the molecular expression levels of biomarkers of neural stem cells (NSC) and neurons in the hippocampus of wild-type adult rats, and the effects on hippocampal neurogenesis. Methods: Eighteen male Sprague-Dawley (SD) rats were randomly divided into 3 groups based on the table of random numbers (n=6 in each group). In low-intensity group and high-intensity group, rats were injected intravenously through tail vein with 200 μl Pg ATCC33277 [1.0×103 and 1.0×108 colony forming unit (CFU), respectively] 3 times per week for 8 weeks. In the sham group, 200 μl of phosphate buffer saline (PBS) was given instead. Behavioral tests: the navigation and the exploration tests using Morris water maze (MWM) were applied to evaluate learning and memory ability of rats. Immunohistochemistry was performed to detect cells positively expressing nestin, doublecortin (DCX) and neuronal nuclei (NeuN) in the subgranular zone (SGZ) of rats in each group. Western blotting was used to evaluate the expression levels of nestin, DCX and NeuN in rat hippocampus. Results: Learning and memory abilities: on day 5 of navigation test, the lagency time was 22.83 (16.00, 38.34) s in the high-intensity group, significantly longer than the sham group [5.59 (5.41, 6.17) s] (t=-11.17, P<0.001). There were no significant differences between the low-intensity group [9.85 (8.75, 21.01) s] and the sham group (t=-6.83, P=0.080). Results in the exploration test showed that, in the high-intensity group, the number of fime crossing over the previous platform area within 60 s was 1.50 (1.00, 2.00), significantly less than the sham group [4.00 (2.75, 4.00)] (t=9.75, P=0.003); no significant differences between the low-intensity group [2.50 (2.00, 3.00)] and the sham one (t=4.50, P=0.382). Immunohistochemistry showed that the nestin+ cell density in the low-intensity group [(35.36±4.32) cell/mm2] and high-intensity group [(26.51±5.89) cell/mm2] were significantly lower than the sham group [(59.58±14.15) cell/mm2] (t=24.21, P=0.018; t=33.07, P=0.005); as for the mean absorbance of DCX+ cells, the low-intensity group (0.007±0.002) and the high-intensity group (0.006±0.002) were significantly lower than the sham group (0.011±0.001) (t=0.004, P=0.018; t=0.006, P=0.005); compared with the sham group [(1.13±0.14)×103 cell/mm2], the density of NeuN+ neurons in the high-intensity group [(0.75±0.08)×103 cell/mm2] was significantly reduced (t=0.38, P=0.017), and was not significantly changed in the low-intensity group [(0.88±0.19)×103 cell/mm2] (t=0.25, P=0.075). Western blotting results showed that, compared with the sham group, the expression levels of nestin, DCX, and NeuN were significantly reduced in the high-intensity group (t=0.74, P<0.001; t=0.18, P=0.014; t=0.35, P=0.008), but were not statistically changed in the low-intensity group (t=0.18, P=0.108; t=0.08, P=0.172; t=0.19, P=0.077). Conclusions: Pg injected through tail vein may reduce learning and memory abilities of wild-type rats, and may reduce the number of nestin, DCX, and NeuN-positive cells, and the protein expression levels of the above molecules in the hippocampus.

Stone toolmaking difficulty and the evolution of hominin technological skills

Stone tools are a manifestation of the complex cognitive and dexterous skills of our hominin ancestors. As such, much research has been devoted to understanding the skill requirements of individual lithic technologies. Yet, comparing skill across different technologies, and thus across the vast timespan of the Palaeolithic, is an elusive goal. We seek to quantify a series of commensurable metrics of knapping skill across four different lithic technologies (discoids, handaxes, Levallois, and prismatic blades). To compare the requisite dexterity, coordination, and care involved in each technology, we analysed video footage and lithic material from a series of replicative knapping experiments to quantify deliberation (strike time), precision (platform area), intricacy (flake size relative to core size), and success (relative blank length). According to these four metrics, discoidal knapping appears to be easiest among the sample. Levallois knapping involved an intricate reduction sequence, but did not require as much motor control as handaxes and especially prismatic blades. Compared with the other Palaeolithic technologies, we conclude that prismatic blade knapping is set apart by being a skill intensive means of producing numerous standardised elongate end-products.

The primary dolostone in the Meso-Neoproterozoic: Cases study on platforms in China

Meso-Neoproterozoic dolostone is abnormally well-developed in the platform areas in China, detailly, in the Mesoproterozoic Calymmian Wumishan Formation of North China Basin, Neoproterozoic Ediacaran Qigbulak Formation of Tarim Basin, and the Neoproterozoic Ediacaran Dengying Formation of Sichuan Basin. The outcrops and drilling cores from these basins show that these dolostones are mostly thick-bedded to massive, with mud-sized to silt-sized crystalline dolostone reaching 86%–97% of the total dolostone thickness. These dolostones basically suffered no secondary metasomatism, regardless of containing microorganisms (such as algae and bacteria) or not. The analyses of sedimentary palaeogeographic features indicate that: (1) the Meso-Neoproterozoic dolostone nearly covered the entire area basins, and was widely deposited in supratidal to intertidal zones, as well as in open platform environments; (2) the dolostone was subdivided according to the crystalline size, with the distribution controlled by geomorphology, i.e., the pure mud-sized crystalline dolostone developing in depression areas, whereas the grainy mud-sized crystalline dolostone or the mound stromatolitic mud-sized crystalline dolostone developing in uplift areas; (3) deep-water basins developed between the carbonate platforms, and the seismic profiles show that these basins were formed by syngenetic deep faults in the Meso-Neoproterozoic strata. These syngenetic faults increased Mg2+ concentration in the seawater by injecting rich-Mg2+-bearing hydrothermal fluids into the carbonate platforms. The analyses of geochemical and paleoclimatic indexes reveal that there is no obvious difference in carbon and oxygen isotope ratios between dolostones having different textures, with the ratios similar to those of the global seawater of the Meso-Neoproterozoic, indicating that the silt-sized crystalline dolostone has the same sedimentary origin as the mud-sized crystalline dolostone, i.e., the former is from authigenic recrystallization of the latter rather than secondary metasomatism. Therefore, whatever the crystalline sizes are, the dolostones are all originated from sedimentation. All the petrological, sedimentary and geochemical data suggest that the dolostones covering almost the whole Meso-Neoproterozoic typical platform areas of China are of relatively primary sedimentary origin.

NUMERICAL INVESTIGATION OF ABOVE-SEA GAS DISPERSION AND EXPECTED EXPLOSION OVERPRESSURE ON THE OFFSHORE PLATFORM UNDER VARYING SEA AND WEATHER CONDITIONS

Above sea gas dispersion resulting from subsea release could cause explosion risk to a nearby offshore platform. Past researchers performed a CFD-based assessment of above sea gas dispersion under the varying sea and environment conditions, but the resulting expected overpressure consequences due to the potential ignition of dispersing flammable on an offshore platform under such varying conditions were not investigated. Overpressure estimates under varying sea and weather parameters could support the practitioners in determining the most critical conditions that correspond to the worst consequences on the offshore platform thus, the research could contribute to process safety. Therefore, in this study, above sea gas dispersion under varying wind speeds in range 2-6 m/s and sea surface release rates of 390 kg/s and 872 kg/s were performed using a Fire Dynamics Simulator (FDS), and expected overpressure consequences in each case are estimated based on the flammable concentration distribution on the platform. It was found that low wind speed and less release rate do not pose a danger to the platform. However, compared to the low wind-low release rate, 35% greater platform area was covered by flammable gas cloud at a high wind speed of 6 m/s and a high release rate of 872 kg/s. This could cause overpressure of 70 kPa in 7.5% of the platform region, which is identified as the most dangerous release rate and wind speed condition. It is suggested that the operators on the offshore platform take special care in high wind and release rate scenarios to avoid flammable cloud accumulation and resulting overpressure consequences.&#x0D; Keywords: CFD modelling, FDS, offshore platform, above-sea gas dispersion, flammable concentration, overpressure

Comparison anti-oxidant and neuroprotective effects of extra-virgin olive oil, donepezil and rosmarinic acid on aluminum chloride-induced Alzheimer’s in rat models

In this study, it was aimed to investigate the effects of EVOO, rosmarinic acid and donepezil in Alzheimer's model to be created with AlCl3 in rats. For this reason, administration of 100 mg/kg aluminum chloride (AlC3) for 15 days to Sprague Dawley adult male rats; donepezil, Extra-virgin olive oil (EVOO) and rosmarinic acid were administered to three different groups for 21 days by applying treatment protocols. With this study, we were able to demonstrate that cognitive impairment has been occurred after 15 days of AlCl3 administration by oral gavage and treatment protocols prevented the occurrence of AD pathology histopathologically. We also showed that oxidative damage findings which are positively Congo-red stained cell cytoplasm and impaired cell integrity have been observed in serum and hippocampus. Besides, treatment groups showed better cognitive and motor performance, and there was no damage to the cells in control and treatment groups. In the rotarod motor performance test, a significant increase was observed in the donepezil group compared to the AlCl3 group at speeds of 26 and 30 rpm. In MVM, on the 5th day of the experiment, a significant increase was observed in the donepezil group compared to the AlCl3 group, as they were spending more time in the hidden platform area. These results show that 15 days of aluminum exposure is effective in creating a moderate Alzheimer’s pathology, but further chronic research is necessary to explain the efficiencies of rosmarinic acid and EVOO in treatment.

Algorithm for calculating neotectonic stresses in platform areas by the structural-geomorphological method

An algorithm for calculating stress values proposed here is based on the results of reconstruction performed by L.A. Sim’s structural-geomorphological method for platform areas. This method makes it possible to determine the orientation of the axes of principal stresses for the shear zones from the lineament analysis of satellite images and photographs and Gzovsky’s palette, and to identify the lineaments characterizing the basement active faults which are covered by sediments. It is proposed that the dataset obtained will be subjected to the algorithm of the second-stage method of Cataclastic Analysis of faulting displacements, in which the Mohr diagram is used to calculate the stress values normalized for the cohesion strength of the massif. The further determination of the cohesion strength and absolute stress values is based on the data for lithostatic pressure and fluid pressure in the fracture-pore space of the massif (either measured or prescriptive). The stress calculation algorithm was tested on a small area (60 square km of satellite imagery) near the territorial district of Seversk – the southern border of the West Siberian Platform. The calculations have shown that with the fluid pressure variations ranging from hydrostatic values to twice higher than those, the cohesion strength of a rock mass at the base of the sedimentary cover (500 m depth) is in the range of 41.0 to 16.8 bar, and the level of maximum tangential stresses lies in the range of 75 to 31 bar.

Analysing the interactions and complexities of the operations in the production area of an FPSO platform using the functional resonance analysis method (FRAM)

The technological evolution of several productive sectors of society has demanded the same level of evolution for the oil and gas industry, both for energy production and their own systems’ functioning. The production of crude oil and natural gas in offshore units is one of the answers to this demand. However, these offshore units have critical onboard activities and risks, notably FPSO units; it is necessary to have adequate recognition of the elements that can support these activities and manage these risks, enabling productive and safe operations. In this sense, this article aims to increase the understanding of the complex interactions and inherent safety issues that arise in the operations of FPSOs, observing and analysing the work done onboard such platforms. The FRAM methodology has been chosen because it allows for the recognition and analysis of the complex interactions involving workers, equipment, system and offshore environment, focusing on the oil treatment area of the process plant. The results demonstrated some interesting findings regarding onboard safety and the relationship between human competences, work demands and process safety.

Screening, Monitoring, and Remediation of Legacy Wells to Improve Reservoir Integrity for Large-Scale CO2 Storage—An Example From the Smeaheia Structure in the Northern North Sea

Carbon capture and storage (CCS) is an inevitable action to achieve CO2 emission reduction targets including becoming net-zero by 2050. Increased efforts are therefore required to identify suitable locations for large-scale CO2 storage. In addition to large aquifers, shut down oil and gas fields in the North Sea are logical candidates for offshore large-scale CO2 storage because of their proven storage capacity, reliable caprock integrity, established infrastructure, and public acceptance. However, in some cases, old and legacy wells are subject to high uncertainties in their integrity, and they can compromise CO2 containment in such reservoirs. On the Norwegian Continental Shelf (NCS), such wells are numerous even outside of oil and gas production areas, i.e., legacy wells affecting aquifers. Therefore, there is a clear need for reliable and cost-effective technologies for well integrity evaluation and remediation. This paper discusses a workflow for screening, monitoring, and remediation of legacy wells. In a first stage, the screening of the Horda Platform areas suggested the need for integrity investigation for the exploration well 32/4-1 T2, drilled into the Alpha structure of the Smeaheia fault block if CO2 is stored in the structure. Our initial well screening of drilling documentation indicates that the well is not suitable to be reused for CO2 injection and geophysical monitoring is recommended. In a second stage, a numerical representation of the well architecture is built including realistic geological setting. We evaluate the sensitivity of non-invasive low-frequency electromagnetic monitoring to corrosion levels in the casing. Numerical end-member simulations of assuming casing corrosion of different degrees by changing material conductivity are performed. Results comparing different corrosion scenarios with a base case (no corrosion) give an above noise signal at receiver locations enabling to separate the different cases. Comparison of the gained electrical fields at seafloor suggests that well casing corrosion monitoring should be possible. Finally, the electrochemical deposition potential of the Sognefjord Formation water is analyzed, revealing depositional potential for portlandite, which might be useful for cement remediation. We recommend such an analysis for all legacy wells penetrating candidate reservoirs for future CO2 or hydrogen storage.

Reservoir evaluation of the Eastern Tethyan Middle Eocene Larger Benthic Foraminifera dominated carbonates from Pakistan.

The Eocene Large Benthic Foraminiferal limestones of the Tethyan margins are proven hydrocarbon reservoirs. This study examines the controls on porosity and permeability development of the producing Middle Eocene Pirkoh Member of the Eastern Tethys using well core data from Well Zx-01 from the Punjab Platform area, Central Indus Basin, Pakistan. The standard petrographic and core analysis techniques were adopted to determine these controls. Petrographic studies revealed three microfacies comprising bioclastic packstone to floatstone, bioclastic wackestone and mud-wackestone microfacies. The allochems belong to benthic foraminifera including Nummulites sp., Discocyclinids sp.., Coralline algae, Assilina sp., Lockhartia sp., Coralline algae and Gastropods along with the other bioclastic debris. These allochems were found embedded in the micritic matrix with extensive cementation of calcite. The diagenetic events included cementation, compaction, dolomitization, fracture filling and neomorphism. Based on microfacies, the environment of deposition is interpreted to be a high-energy zone of the middle ramp in shallow marine environment. Subsurface core indicates that the porosity of the reservoir is low to high ranging between 6 to 27.47% and permeability is found low to fair ranging between 0.03 to 7.73 mD, found closely related to microfacies and diagenetic modifications. This study is a first attempt to document the reservoir facies of the non-reefal carbonates of the Pirkoh limestone that would help to exploit the reservoir's potential of the carbonate platforms developed in similar settings worldwide.

Research on Commutation Switch to Control Three-phase Unbalance and Azimuth Configuration

The randomness of each phase load in the station combined with the distribution of new energy into the network has caused the three-phase unbalance to become more and more serious. The use of commutation switch to switch the three-phase unbalance load effectively solves the problem. Considering the number of commutation switches, the particle swarm algorithm is used to optimize the configuration orientation of the commutation switch and to improve the accuracy of the installation location of the commutation switch. Effectively reduces the three-phase unbalance in the platform area.

Tectonic factors of the chemical compound’s composition of plains’ groundwater

Tectonic factors within the platform areas determine the features of the near-surface part of the lithosphere, including groundwater. The pattern of tectonic disturbances affects both the features of the occurrence of aquifers and their hydrogeochemical composition. The purpose of this work is to determine the sources of boron intake into the groundwater of some districts of the Lipetsk region. The assessment of these processes was carried out by us using remote sensing and hydrogeological studies of a number of areas of the Eastern European Platform. Increased concentrations of boron in groundwater confined to neotectonic structures, including the valley of the Don River flowing through the Losev seam zone separating the Central Russian Upland and the Oka-Don lowland, were revealed. The increased boron contents (more than 0.5 mg/dm3) are confined to underground aquifers of Devonian age. It is revealed that these concentrations are mainly characteristic of structures of a negative sign. Deep tectonic processes are designated as the main source of boron intake.

Syn‐ to post‐rift alluvial basin fill: Seismic stratigraphic analysis of Permian‐Triassic deposition in the Horda Platform, Norway

AbstractThe Permian‐Triassic alluvial rift succession in the Horda Platform area is analysed to construct a refined depositional model. The study demonstrates how subsurface continental rift successions may be stratigraphically subdivided and correlated by integrating seismic and well‐log data in concert with conceptual models. Regional unconformities mark the top and base of the Permian‐Triassic succession, which is sub‐divided into six seismic stratigraphic sequences, delineated by erosional‐ and non‐depositional surfaces. The definition of seismic stratigraphic sequences is based on seismic facies trends and Gamma Ray log signatures. Time‐thickness maps combined with geometries in cross‐section display the depocentre development. During the Permian‐Triassic, the Horda Platform experienced faulting, shaping the Caledonian pre‐rift landscape into a series of N–S trending half‐graben basins, contemporaneous to a gradual climate change from arid in the Permian to humid in the latest Triassic. The basin underwent three phases of rifting during the Late Permian‐Middle Triassic: (1) disconnected heterogeneous depocentres with strain concentrated in the west; (2) depocentres expanded northward; and (3) mature half graben development with widely distributed strain. Vertical lithological changes in mudstone/sandstone dominance reflect varying rates of accommodation and sediment supply (A/S). Systematic A/S variation reflects strong climatic fluctuations, which controlled facies patterns during both tectonic quiescence in the Middle‐Late Triassic, and during syn‐rift sedimentation. The Permian‐Triassic tectono‐sedimentary development in the Horda Platform area provides valuable lessons on the influence of faulting on depocentre development, how the interplay between tectonic and climatic forcing is expressed in subsurface continental deposits, and aid the characterisation of reservoirs.

Stocks and flows of sand, gravel, and crushed stone in China (1978–2018): Evidence of the peaking and structural transformation of supply and demand

Aggregates are the most extracted material resources by weight worldwide. As an important resource for buildings and infrastructure, aggregates, however, are now facing shortages and are associated with negative environmental and social impacts. More attention is now paid to the sand and gravel issues, however, recent investigations are often found ambiguous in definition or adopting over-simplified accounting methodology. To bridge the knowledge gap, first, we conducted a detailed literature investigation to clarify the associated terms. Then we established a systematic material flow and stock accounting framework to map the social metabolism of aggregate resources for the largest aggregates consumer and producer—China. Our results show during 1978–2018, the inflows of China's aggregates increased by 13 times (1.3 to 17.3 billion tons) and the stocks increased by 15 times (18.3 to 285.5 billion tons). We observed both aggregate inflows and stocks have shown a relative decoupling from economic growth. Around 2014, inflows entered a platform area and the dominated consuming sector shifted from buildings to infrastructure. Due to supply shortages and policy interventions, the source of primary supply sees a sustainable transition: manufactured aggregates (instead of natural aggregates) gradually dominated, accounting for 78% of the total primary supply in 2018. Additionally, regarding accumulated stocks of aggregates, it is expected to see rapid growth of aggregate waste in the near future. It is essential to foster a well-functioned circular system to achieve the sustainable development of the aggregate industry.

Late Devonian (Frasnian–Famennian) palynomorphs from the Padeha and Bahram Formations of Shahzadeh Mohammad section, northwest of Kerman, Iran

A diverse and well-preserved microphytoplankton assemblage is reported from a measured section of Frasnian–Famennian (Upper Devonian) Padeha and Bahram Formations in Shahzadeh Mohammad area, northwestern Kerman, southeast Iran. The palynoflora assemblage contains 17 genera and 23 species of acritarchs, chitinozoa, scolecodont and rich miospore taxa. 57 species (25 genera) of miospores were identified and 5 assemblage biozones were defined from the Shahzadeh Mohammad section. The miospore composition is similar to neighboring localities in Southern and Northern Iran, but it shows significant similarities with palynoflora from more distant localities, e.g. Saudi Arabia, Western Australia or Algeria. This implies a close relationship between the Iranian platform and other areas of the Northern Gondwana and southern Laurentia Domain during the late Devonian. The investigated section was deposited in a shallow marine environment with tropical conditions during the Frasnian-Famennian period.

Personnel identification and distribution density analysis of subway station based on convolution neural network

In this paper, a method based on convolution neural network and multi-camera fusion is proposed to improve the recognition accuracy of crowd and then the personnel distribution of subway station platform is analyzed. In this method, tensorflow is used as the deep learning training framework and the yolov4 neural network algorithm is used to identify the subway station platform area using three videos synchronously. Through affine transformation and time average statistics, the passenger density of each sub-area is calculated and the distribution of personnel density in the whole area is analyzed. The results show that the number of people recognized by multiple cameras is 58% higher than that by single camera. The new recognition method has high recognition rate for the actual scene with large crowd and more obstacles. Finally some areas with high risk of personnel aggregation have been found, which should be the focus of safety monitoring.