Preliminary Study of Chemical Elements Distribution in Petroleum Source Rocks Donga and Yogou Formations of the Termit Sedimentary Basin (Est-Niger)

XRF and EDX analyses were carried out on 18 batches of representative raw samples to determine the distribution of major chemical elements in the petroleum source rocks of Donga and Yogou formations of Termit sedimentary basin. The chemical composition of these formations is dominated by silicon (Si), aluminum (Al) and iron (Fe). This is consistent with the oxide composition, which is also dominated by silicon oxide (SiO2), aluminum oxide (Al2O3) and iron monoxide (FeO). No less important chemical elements are calcium (Ca), potassium (K), sulfur (S), titanium (Ti), magnesium (Mg), manganese (Mn) and barium (Ba), as well as some of their oxides. All these major chemical elements are carried by silicate detrital minerals associated with pyrite and goethite and/or clay minerals such as kaolinite and interstratified illite, smectite and chlorite. This trend is illustrated by the values of the Si/Al and SiO2/Al2O3 ratios.

Petroleum exploration breakthrough and geological significance in Cretaceous Yingcheng and Denglouku formations of Shuangcheng area, northern Songliao Basin, NE China

Based on drilling geological,geochemical,geophysical and production test data,the characteristics of source rocks,reservoir rocks and caprocks,as well as the process of hydrocarbon generation,trap evolution and oil accumulation of the oil-bearing assemblage composed of the Cretaceous Yingcheng Formation(K1yc)and Denglouku Formation(K1d)in the Shuangcheng area,northern Songliao Basin,NE China,were analyzed by using the research methods for petroleum systems.The source rocks mainly exist in K1yc,with the organic matters mainly originated from lower aquatic organisms and algae,and reaching the grade of high-quality source rock in terms of organic abundance.The crude oil,which is characterized by low density,high freezing point and high wax content,is believed to have generated by the K1yc source rocks.The reservoir rocks include K1d sandstones and K1yc glutenites.The mudstone in the fourth member of K1d serves as the direct caprock of the oil reservoir.The oil was generated during the period between Yaojia Formation and Nenjiang Formation,and then accumulated during the periods of Nenjiang Formation and Paleogene–Neogene.The traps evolved in three stages:the late Yingcheng Formation,the late Quantou Formation and the late Nenjiang Formation,forming structural and structural-lithologic reservoirs.It is concluded that good source-reservoir-caprock assemblage,late hydrocarbon charging,short migration distance and stable tectonic setting are favorable factors for the formation of oil reservoirs.

A survey on joint-operation application for unmanned swarm formations under a complex confrontation environment

With the rapid development of informatization,autonomy and intelligence,unmanned swarm formation intelligent operations will become the main combat mode of future wars.Typical unmanned swarm formations such as ground-based directed energy weapon formations,space-based kinetic energy weapon formations,and sea-based carrier-based formations have become the trump card for winning future wars.In a complex confrontation environment,these sophisticated weapon formation systems can precisely strike mobile threat group targets,making them extreme deterrents in joint combat applications.Based on this,first,this paper provides a comprehensive summary of the outstanding advantages,strategic position and combat style of unmanned clusters in joint warfare to highlight their important position in future warfare.Second,a detailed analysis of the technological breakthroughs in four key areas,situational awareness,heterogeneous coordination,mixed combat,and intelligent assessment of typical unmanned aerial vehicle(UAV)swarms in joint warfare,is presented.An in-depth analysis of the UAV swarm communication networking operating mechanism during joint warfare is provided to lay the theoretical foundation for subsequent cooperative tracking and control.Then,an indepth analysis of the shut-in technology requirements of UAV clusters in joint warfare is provided to lay a theoretical foundation for subsequent cooperative tracking control.Finally,the technical requirements of UAV clusters in joint warfare are analysed in depth so the key technologies can form a closed-loop kill chain system and provide theoretical references for the study of intelligent command operations.

New Insights into the Depositional Environments of Ordovician Carbonate Formations in the Yubei Area of Tarim Basin Based on Standard Microfacies Types

Objective The Yubei area is located in the mid-east Maigaiti slope of southwestern Tarim Basin,China,with an exploration history of several years.Recent exploration has preliminarily indicated that the Ordovician carbonate formations in this area have some oil and gas potential.Carbonate microfacies provides material basis for reservoir development,seal formation and

Maneuvering Angle Rigid Formations With Global Convergence Guarantees

Angle rigid multi-agent formations can simultaneously undergo translational,rotational,and scaling maneuvering,therefore combining the maneuvering capabilities of both distance and bearing rigid formations.However,maneuvering angle rigid formations in 2D or 3D with global convergence guarantees is shown to be a challenging problem in the existing literature even when relative position measurements are available.Motivated by angle-induced linear equations in 2D triangles and 3D tetrahedra,this paper aims to solve this challenging problem in both 2D and3D under a leader-follower framework.For the 2D case where the leaders have constant velocities,by using local relative position and velocity measurements,a formation maneuvering law is designed for the followers governed by double-integrator dynamics.When the leaders have time-varying velocities,a sliding mode formation maneuvering law is proposed by using the same measurements.For the 3D case,to establish an angle-induced linear equation for each tetrahedron,we assume that all the followers'coordinate frames share a common Z direction.Then,a formation maneuvering law is proposed for the followers to globally maneuver Z-weakly angle rigid formations in 3D.The extension to Lagrangian agent dynamics and the construction of the desired rigid formations by using the minimum number of angle constraints are also discussed.Simulation examples are provided to validate the effectiveness of the proposed algorithms.

Depositional age and tectonic environment of the Gouap banded iron formations from the Nyong group,SW Cameroon:Insights from isotopic,geochemical and geochronological studies of drillcore samples

The discovery of the Gouap banded iron formations(BIFs)-hosted iron mineralization in the northwestern of the Nyong Group(Ntem Complex)in southwestern Cameroon provides unique insights into the geology of this region.In this contribution,we firstly report detailed study of geochemistry,isotopic and geochronology of well preserved samples of the Gouap BIFs collected from diamond drillcores.The Gouap BIFs consist mainly of amphibole BIFs and amphibole-pyrite BIFs characterized by dominant Fe_(2)O_(3)+SiO_(2)contents and variable contents of CaO,MgO and SO_(3),consistent with the presence of amphibole,chlorite,epidote and pyrite,formed during amphibolite facies metamorphism and overprinted hydrothermal event.The amphibole–pyrite BIFs are typically enriched in trace and rare earth elements(REE)compared to the amphibole BIFs,suggesting the influence of detrital materials as well as secondary hydrothermal alteration.The Post Archean Australian Shale(PAAS)-normalized REE–Y profiles of the Gouap BIFs display positive La,Eu anomalies,weak negative Ce anomalies,indicating a mixture of low-temperature hydrothermal fluids and relatively oxic conditions probably under relative shallow seawater.We present here the first isotopic data of BIFs within the Ntem Complex.Theδ^(30)Si_(NBS28)values of the quartz from the Gouap BIFs vary from-1.5‰to-0.3‰and from-0.8‰to-0.9‰for the amphibole BIFs and amphibole–pyrite BIFs,respectively.The quartz hasδ^(18)OV-SMOW values of 6.8‰–9.5‰(amphibole BIFs)and 9.2‰–10.6‰(amphibole–pyrite BIFs).The magnetite from the Gouap BIFs showsδ^(18)O values ranging from-3.5‰to-1.8‰and from-3‰to-1.7‰for the amphibole BIFs and amphibole–pyrite BIFs,respectively.Moreover,the pyrite grains in the amphibole–pyrite BIFs displayδ34S values of 1.1‰–1.8‰.All isotopic data of the Gouap BIFs confirm that they might have precipitated from low-temperature hydrothermal fluids with detrital input distant from the volcanic activity.According to their geochemical and isotopic characteristics,we propose that the Gouap BIFs belong to the Superior type.In situ U–Pb zircon dating of BIFs was conducted to assess the BIF depositional age based on strong evidence of zircon in thin section.The Gouap BIFs were probably deposited at 2422±50 Ma in a region where sediments extended from continental shelf to deep-water environments along craton margins like the Caue Formation of the Minas Supergroup,Brazil.The studied BIFs have experienced regional hydrothermal activity and metamorphism at 2089±8.3 Ma during the Eburnean–Transamazonian orogeny.These findings suggest a physical continuity between the protocratonic masses of both Sao Francisco and Congo continents in the Rhyacian Period.

Discovery of Multiple Tectonic Reformations of the Eastern Yingen-Ejinaqi Basin:Evidence from Detrital Chronology

Objective The widely-distributed reformed basins in China are currently major areas for oil and gas exploration.Poststage tectonic movement of modified basins often plays an important role in controlling petroleum accumulation,migration and distribution(Liu and Yang,2000).The petroliferous Carboniferous-Permian Yingen-Ejinaqi Basin is located in the junction area between the North China Craton and the Central Asian Orogenic Belt(Fig.1 a).

Metamorphic disturbances of magnetite chemistry and the Sm-Nd isotopic system of reworked Archean iron formations from NE Brazil

Iron formations are valuable archives of sedimentary conditions and post-depositional events.However,geochemical proxies commonly used to determine genetic characteristics can be variably modified during metamorphism and deformation,hampering their use as records of regional geological events.This work focuses on strongly reworked magnetite-quartz-rich rocks from the São Josédo Campestre Massif,one of the oldest fragments of preserved crust in South America.The genetic classification of these magnetite-quartz-rich rocks is not straightforward because primary assemblages and textures were variably modified by granulite facies metamorphism during a regional Paleoproterozoic migmatization event.To address genetic ambiguities,we analyzed their magnetite and pyroxene chemistry,wholerock geochemistry,and Sm-Nd isotopes.Magnetite chemistry indicates that pyroxene-poor iron formations(Type B)are low in trace elements such as Ti,Al,V,and Mn,suggesting a chemical similarity to iron formations elsewhere.In contrast,magnetites from pyroxene-enriched Type A iron formations are rich in trace elements and more akin to magnetite crystallized from higher temperature systems,such as skarn and IOCG.The^(147)Sm/^(144)Nd of these rocks show substantial variation even at the outcrop scale,indicating a locally-controlled,highly heterogeneous mixture of Archean,Paleoproterozoic,and Neoproterozoic sources.Therefore,our geochemical tools point out to heterogenous signatures of these magnetitequartz rocks and proxies compatible with both low and high-temperature conditions and age of deposition spanning sources from the Archean to the Neoproterozoic.We interpret that the studied São Josédo Campestre magnetite-quartz rocks represent Archean iron formations with original magnetite chemistry and isotopic signatures variably modified by metamorphism and by at least one deformation-related hydrothermal event.These results contrast with similar examples from China and Greenland where iron formations either preserved the magnetite chemistry or the primary isotopic signatures.Our study indicates that metamorphism can selectively affect chemical proxies used to study iron formations and undermine the genetic classification of iron ores.Thus,these proxies should be carefully applied in the interpretation of syn-depositional environments of polydeformed belts.

Variability of Soil Properties as Affected by Geological Formations in Southwestern Iran

Parent material is the most important soil forming factor.Therefore,relation between geological forma- tion and soil properties was investigated in southwestern Iran.First,geological formations of Asmari,

Studies on Progressive Reactions Leading Formations of Different Types of Barium Ferrites

The present investigation is concerned with the reaction of barium and iron nitrates mixtures using three different molar ratios, 1:1 (Ⅰ), 1:2 (Ⅱ) and 2:1 (Ⅲ) at different temperatures as pointed out from the DTA data. The reaction products exhibit 12 compounds namely, Ba(NO3)2, αFe2O3, Fe3O4, BaFeO3, BaFeO2.9, hexagonal BaFeO3-x, tetragonal BaFeO3-x, BaFe2O4, αBaFe2O4, Ba2Fe6O11, Ba5Fe14O26 and BaFe12O19. The formation of these products depend on the molar ratio between the reactants and the reaction temperature. The reaction products were studied by DTA and TG techniques and characterized by X-ray diffraction patterns, magnetic susceptibility data and scanning electron microscopy, SEM.

Assessment of Potential Ecological Risk of Heavy Metals in Soils from Waste Dumpsites in Military Formations in Makurdi, Nigeria

Chemical fractionation of toxic metals (As, Cd and Zn) along the soil profile at waste dumpsites in military formations for dry and wet seasons using Tessier’s sequential extraction procedure was determined using AAS techniques. The order of yield across the fractions was mainly: exchangeable (F1) 2) 3) 4) 5). Statistical analysis (p < 0.05) indicated that there was no significant variation between the values of results obtained from dumpsites A and B of each sampling station. However, the variation between the dumpsites and control was significant (p > 0.05) in most stations. The pollution index was assessed using the degree of contamination (Cd), the modified degree of contamination (mCd), potential ecological risk and mobility factor. The Cd indicated that NFB top soil was considerably contaminated (16.3) while the soils (20 - 40 and 40 - 80 cm) recorded moderate (13.6) and low (5.60) contaminations respectively. Top soil of NSM was moderately contaminated while the contamination status of NPS, NFB and SFB waste dump soils across the depths was “low”. The mCd index for NFB dump soil was “moderate” (2.33) and subsoils (20 - 40 and 40 - 80 cm) were “low” (1.94) and “Nil to very low” (0.800) respectively. The mCd for the other three dumpsites was “Nil to very low” except the top soil of NSM which was “low”. The order of the toxic metals mobility in the studied soils using the Mobility factor (Mf) for dry and wet seasons was Cd > As > Zn and Zn > Cd > As respectively.

A Novel Cellular Autoaggregative Developmentally CRP Regulated Behaviour Generates Massively Chondrule-Like Formations over Surface of Old <i>Escherichia coli</i>K-12 Macrocolony Biofilms

How Escherichia coli bacteria develop a particular colonial, 3-D biofilm morphological pattern is still a poorly understood process. Recently, we reported a new E. coli K-12 morphotype exhibited by old macrocolonies described as volcano-like. The formative developmental process of this morphotype has been presented as a suitable experimental model for the study of 3D patterning in macrocolony biofilms. Here, we report the optical microscopy observations and genetic analysis that have unveiled the existence of a novel autoaggregative behaviour which generates massive lumpiness over the surface of the volcano-like macrocolonies. These lumpy formations are generated by the autoaggregation and strong interaction of tightly packed bacterial cells in structures with a chondrule-like appearance which give the colony’s surface its characteristic microscopic lumpy phenotype. Furthermore, they exhibit different levels of maturation from the edge to the center of the colony. Hence, its generation appears to follow a spatiotemporal program of development during the macrocolony’s morphogenesis. Interestingly, the agar’s hardness influences the morphology exhibited by these formations, with high agar concentration (1.5%, 15 g/L) suppressing its development. This new auto-aggregative E. coli’s behaviour does not require the activity of the biofilm master regulator CsgD, the adhesiveness of flagella, pili type 1, adhesin Ag43, β-1,6-N-acetyl-D-glucosamine polymer-PGA, cellulose or colanic acid, but it is under glucose repression and the control of cAMP receptor protein (CRP). The possible physiological role of these chondrule-like formations in the adaptability of the colony to different stressful environmental conditions is discussed.

The Geological Formations of Koun Fao (East of Côte d’Ivoire): Petrographic Characterization and Associated Deformations

This study aims to contribute to improve knowledge on geological formations of Comoé basin. The petrographic study of the geological formations of Koun Fao has highlighted two major lithological families: magmatic rocks consisting of monzonites, monzogranites, diorites, biotite granodiorites, syenites, porphyritic micromonzonites and porphyritic dacite and metamorphic rocks from sedimentary origin (quartz schists, meta-greywackes, schists, andalusite chloritoschist and paragneiss). These formations are affected by amphibolite to greenschist facies metamorphism and hydrothermal alteration (pervasive and vein) marked by the presence of quartz, epidotes, chlorites and sericite. Minerals such as andalusite, muscovite and chlorite characterize a local low pressure contact metamorphism in the andalusite chloritoschist. Remote sensing data (Landsat 8 image) coupled with field data allowed the production of a geological map of the area. The study of the structures and microstructures highlighted two deformation mechanisms. These are flattening and simple shear (ductile and brittle). The study area is affected by four deformation phases: D1 marked by a N-S to NNE-SSW elongation, D2 marked by a NW-SE to NNW-SSE compression phase, D3 which is a NE-SW to NNE-SSW transpression phase and D4, responsible for late structures, marked by a NW-SE to NNW-SSE transpression phase.

Discrete Quantum Transitions, Duality: Emergence of Physical Structures and Occurrence of Observed Formations (Hidden Properties of Mathematical Physics Equations)

With the help of skew-symmetric differential forms, the hidden properties of the mathematical physics equations that describe discrete quantum transitions and emergence the physical structures are investigated. It is shown that the mathematical physics equations possess a unique property. They can describe discrete quantum transitions, emergence of physical structures and occurrence observed formations. However, such a property possesses only equations on which no additional conditions, namely, the conditions of integrability, are imposed. The intergrability conditions are realized from the equations themselves. Just under realization of integrability conditions double solutions to the mathematical physics equations, which describe discrete transitions and so on, are obtained. The peculiarity consists in the fact that the integrability conditions do not directly follow from the mathematical physics equations;they are realized under the description of evolutionary process. The hidden properties of differential equations were discovered when studying the integrability of differential equations of mathematical physics that depends on the consistence between the derivatives in differential equations along different directions and on the consistence of equations in the set of equations. The results of this work were obtained with the help of skew-symmetric differential forms that possess a nontraditional mathematical apparatus such as nonidentical relations, degenerate transformations and the transition from nonintegrable manifolds to integrable structures. Such results show that mathematical physics equations can describe quantum processes.

Evaluating Sediment Production Caused by the Lithology of the Geological Formations in Sedimentary Basins (Case Study: Lali Area, Khuzestan, Iran)

As sediments are produced and accumulated in sedimentary basins especially in dams’ reservoirs and they highly affect the reservoirs life span, it is essential to scrutinize the effect of lithology and types of geological formations of an area on the life span of reservoirs specifically from the viewpoints of the erodability of these formations due to their lithology type. Lali area, Khuzestan, Iran and the water catchment of the intended area (based on geological situation and Taraz dam situation) are placed in the sedimentary-structural zone of the folded Zagros. The method of this research is based on analyzing the topography and geology maps and field work in order to identify the lithology of the geological formations. In fact, the amount of its erodability has been characterized by the type of the geological formations. The current research aims at putting the geological results, lithological data of the formations types and the outcrop of the soil-lithological units together in order to evaluate the sedimentary and erosive factors of these units and precisely identify the area’s geological formations to remove the ambiguities in this issue. Studies indicate that formations made of looser gypsum and marl like Pabde-Gurpi and Gachsaran are exposed to more sedimentation and erosion than the formations made of compacted lime stone and conglomerate with silica-lime cement such as Bakhtiary and Asmari formations and the sand stones of Aghajari formation reveal the moderate to high resistance. Thus, the lithological identification of the formations, the type of sediments and their looseness and hardness contribute to detect the amount and type of deposits entering into the dam reservoir. The type and amount of these transported and deposited sediments are assessed to predict more suitable optimized ways to exploit dams’ reservoirs.

Understanding hydraulic fracture propagation behavior in tight sandstone–coal interbedded formations: an experimentalinvestigation

Whether hydraulic fractures could connect multiple gas zones in the vertical plane is the key to fracturing treatment to jointly exploit coalbed methane and tight sandstone gas through integrative hydraulic fracturing in tight sandstone–coal interbedded formations. Laboratory true triaxial hydraulic fracturing experiments were conducted on layered specimens with di erent combination types of natural sandstone and coal to simulate the propagation behavior of hydraulic fractures. The effects of the fracture initiation position, fracturing fluid viscosity and injection rate were discussed. The results showed that di erent fracture morphologies could be found. When initiating from coal seams, three patterns of fracture initiation and propagation were obtained:(1) The main hydraulic fracture initiated and propagated along the natural fractures and then diverged due to the effects of in situ stress and formed secondary fractures.(2) The hydraulic fracture initiated and propagated in the direction of the maximum horizontal stress.(3) Multiple fractures initiated and propagated at the same time. With the same fracturing fluid viscosity and injection rate, the hydraulic fractures initiating in sandstones had greater chances than those in coal seams to penetrate interfaces and enter neighboring layers. Excessively small or large fracturing fluid viscosity and injection rate would do harm to the vertical extension height of the induced fracture and improvement of the stimulated reservoir volume. Compared with operation parameters(fracturing fluid viscosity and injection rate), the natural weak planes in coals were considered to be the key factor that a ected the fracture propagation path. The experimental results would make some contributions to the development of tight sandstone–coal interbedded reservoirs.

A review of CO2 storage in geological formations emphasizing modeling,monitoring and capacity estimation approaches

The merits of CO2 capture and storage to the environmental stability of our world should not be underestimated as emissions of greenhouse gases cause serious problems.It represents the only technology that might rid our atmosphere of the main anthropogenic gas while allowing for the continuous use of the fossil fuels which still power today’s world.Underground storage of CO2 involves the injection of CO2 into suitable geological formations and the monitoring of the injected plume over time,to ensure containment.Over the last two or three decades,attention has been paid to technology developments of carbon capture and sequestration.Therefore,it is high time to look at the research done so far.In this regard,a high-level review article is required to provide an overview of the status of carbon capture and sequestration research.This article presents a review of CO2 storage technologies which includes a background of essential concepts in storage,the physical processes involved,modeling procedures and simulators used,capacity estimation,measuring monitoring and verification techniques,risks and challenges involved and field-/pilot-scale projects.It is expected that the present review paper will help the researchers to gain a quick knowledge of CO2 sequestration for future research in this field.

Ore-bearing Formations and Mineral Resource Prospects of the Peripheral Areas of the Tarim Block

The tectonic development of the Tarim block has experienced four stages, i. e. Earth’s core accretion and block formation in the Precambrian, margin splitting, opening-closing and piecing up in the Early Palaeozoic, rift formation and plate unification in the Late Palaeozoic, and basin-mountain coupling and landform shaping in the Meso-Cenozoic, forming six ore-bearing formations and ore deposits of various genetic types in the Tianshan Mountains, Kunlun Mountains and Altun Mountains. In the peripheral areas of Tarim there are four giant intercontinental metallogenic belts passing through, the Central Tianshan and southwestern Tianshan belts in the former USSR and the Qinling-Qilian-Kunlun and Palaeo-Tethys belts in China. According to the macro-analysis on the nearly one thousand known deposits (occurrences) and geophysical-geochemical anomalies, and the information from reconnaissance in some areas, the region has very good prospects for mineral resources. Some of the metallogenic belts may well

Plugging performance and mechanism of an oil-absorbing gel for lost circulation control while drilling in fractured formations

Lost circulation of drilling fluid is one of the most common engineering problems in the drilling process of fractured formations.In this study,an oil-absorbing polymer gel synthesized using compound monomers with rigid and flexible chains was applied to control the oil-based drilling fluid loss while drilling.The microstructure,oil-absorbing performance,and plugging performance the gel was investigated.A large number of dense pores on the surface of the gel were observed,which allowed the oil molecules to enter the internal space of the gel.The initial oil absorption capacity of the gel was fast,and it increased with the increase in the temperature and decrease in the particle size,reaching 20.93 g/g at140℃.At a high temperature of 140℃,the bearing pressure capacity of the gel formula containing particles of different particle sizes reached 7.6 MPa for a fracture of a width of 3 mm,showing that the oil-absorbing gel have excellent plugging performance at high temperature.Plugging mechanism of the gel was investigated through visualized fracture plugging experiments.Results show that the dynamic migratio n,particle-swelling,particle-bridging,particle-aggregation,deformation-filling,and compaction-plugging contribute to the whole lost circulation control process,reflecting that the plugging performance can be effectively enhanced by improving the aggregation and filling degrees of the gel with different particle sizes.

Characteristics of Uranium Mineralization in Red Clastic Formations in the Southwestern Margin of the Ordos Basin

In the southwestern margin of the Ordos Basin,uranium mineralization is primarily hosted by predominantly oxidative red clastic formations in the Lower Cretaceous.The main target layers for uranium exploration are the Madongshan and Liwaxia formations of the Liupanshan Group,followed by the Jingchuan Formation of the Zhidan Group.The host rocks(medium-fine feldspar quartz sandstone),which are bleached to a light grayish white color,contain a minor organic matter component and pyrite.Uranium mineralization changes from surficial infiltration or phreatic oxidation in the upper part to interlayer oxidation in the lower part.Uranium ore bodies are mostly lenticular or tabular in shape,locally shaped like crescent rolls.Individual ore bodies are typically small and shallow.Uranium predominantly manifests as pitchblende and coffinite.Coffinite is usually short and columnar or granular in habit,whereas pitchblende occurs as an irregular colloidal covering on the surface or in fissures of ferric oxide,silicate,clay or carbonate.Secondary uranium minerals are torbernite,uranophane,and uranopilite.Minerals associated with uranium are mainly pyrite,chalcopyrite and,to a minor extent,arsenopyrite and fluorite.The associated elements are Mo,V,Se,Co,Ni,and Mn,the host sandstone being high in Cu and Ba.Overall,the red clastic formations in the southwestern margin of the Ordos Basin are characterized by’five multiples but one low’which means multiple target layers,multiple stages of mineralization,multiple ore body shapes,multiple kinds of uranium minerals,multiple associated elements,but low organic matter.This implies an overall complex uranium metallogenic environment and mineralization process.It is recommended that future uranium exploration should take into consideration regional metallogenic conditions and mineralization features,with target layers in the wide-smooth synclinal slope being focused on.Most uranium deposits are small to medium in size,and the main type of uranium mineralization can vary by target layer.