Helium is a strategic rare gas resource related to national security and the development of high-tech industries, the high-quality development of helium industry chains has a great significance to improve the security of helium resource. This paper through literature and market research, summarizes the progress of helium resource endowmen, exploration and development, supply and demand pattern, trade market and industrial technology, equipment through literature and market research in the world, analyses the development situation of global helium resources industry chains. This study proposes the development status and challenges of China's helium industry and the corresponding development path of helium industry based on the upstream, midstream, downstream and downstream indicators. Most of the countries in the world have not started helium exploration or remain in low exploration level, but the exploration practice shows that global helium resource potential is considerable; helium exploration and development subjects become diversified in recent years, which may change the global helium supply and demand pattern; The helium reservoir forming theory and exploration and development technology are underdeveloped, and the helium extraction equipment is continuously improved; The global helium production capacity, supply and demand，trade pattern market would be profoundly changing. For a long time, the United States has had an absolute say in the global helium trade system, the contradiction between supply and demand would persist for a long time and significant price fluctuations. China's helium development challenges and opportunities coexist considering the global helium industry chain existing pattern and the new trend of development. There is an urgent need to build an independent and controllable , stable and resilient helium industrial chain, and provide helium resources guarantee for the development of high-tech industries.
三江平原地下水开采量随着水稻种植规模快速扩张而大幅增加,2021年水位相对1980年下降5～12 m,是否因此引发地面形变甚至地面沉降成为社会关注的问题.采用二等水准测量方法和比拟法,分析研究了三江平原建三江垦区地下水位降落漏斗地面形变现状与发展趋势及危险性.研究表明,研究区50个二等水准测量点2019-2021年连续3期测量数据对比发现,地表垂向形变量整体较小(最大-18.00 mm,平均变化速率-4.6 mm/a).预测到2040年,地下水位降落漏斗中心水位埋深由2021年的19.88 m降至25 m左右,考虑到研究区"上粘下砂"的二元岩性结构,地下水位下降疏干的地层位于浅上部且厚度有限,地面沉降量仍较小,地质灾害发育程度弱、危险性小.本研究不仅回应了社会关切,也为进一步开展相关研究奠定了基础.
The Bangbule Pb-Zn-Cu deposit is a newly discovered large-scale skarn deposit in the western part of the Gangdese Tectonic Belt in recent years. In this study, the low-temperature thermochronology method was used to reveal the cooling and exhumation history of the Bangbule deposit, evaluate the preservation of the deposit, and improve the uplift and exhumation records of the western Gangdese Tectonic Belt. Apatite fission track age in quartz porphyry is 24±2 ～ 32±3 Ma（1σ）, which indicates the rapid cooling and exhumation of Bangbule deposit during the Oligocene. The simulation of thermal evolution history shows that there are three stages of cooling events in the Bangbule deposit.（Ⅰ） From the Eocene to the Late Oligocene（48～24 Ma）, the cooling rate was between 4.56℃/Ma and 10.64℃/Ma and the cooling event was related to the tectonic background of India-Eurasia collision and the post-collision crustal thickening;（Ⅱ） From Late Oligocene to Middle Miocene（24～14 Ma）, the cooling rate ranges from 0.38℃/Ma to 1.9℃/Ma, which is related to the tectonic background of break-off of the Indian subducted plate.（Ⅲ） From the Middle Miocene to the present（14 Ma to present）, the cooling rate is between 2.28℃/Ma and 9.88℃/Ma, which is related to tectonic background of the north-south rift developed in the Gangdese Tectonic Belt.The cooling event was related to the general uplift of the Gangdese Tectonic Belt since 5 Ma ago. The exhumation thickness of the Bangbule deposit since the Eocene is between 1.5～2.5 km. The cover of the volcanic rocks of the Dianzhong Formation has played a protective role in the preservation of the deposit.
Glaucony is an important authigenic mineral in marine environment and has been widely used in palaeoenvironmental research.In this study, we report the occurrence of the glaucony in the lower Ediacaran Doushantuo Formation in southern Shaanxi Province for the first time.Integrated studies including petrography, in-situ microanalysis and X-ray diffraction（XRD）are carried out to constrain the diagenesis of the glaucony and the oceanic redox condition in the early Ediacaran of this area.Microscopic observations using polarizing microscope and scanning electron microscope（SEM）show that the glaucony mainly fills the pores of quartz, feldspar and other clastic minerals in the form of colloidal precipitates, suggesting authigenic precipitation during the early diagenesis.Since both Fe（Ⅱ）and Fe（Ⅲ）are simultaneously required for glauconitization, glaucony prefers to precipitate around the Fe redoxcline（suboxic conditions）.Accordingly, the occurrence of glaucony in the lower Doushantuo Formation of study section implies suboxic pore water environments.The results of energy dispersive spectroscopy（EDS）show that the glaucony is characterized by high K 2 O and Al 2 O 3 but low Fe 2 O 3 contents which are typical of Precambrian glaucony.The dissolution of detrital minerals along with ion exchange between the seawater and pore-water supplied the elements required for glaucony formation.Compared with contemporaneous glaucony-bearing strata in Weng’an area, Guizhou, the limited vertical distribution of glaucony in the study area indicates that the marine redox condition and paleogeography may have played a joint role in regulating the formation and spread of glaucony.
The effects of parent materials on soil organic carbon（SOC） should not be ignored.This paper took Juhe watershed in Sanhe County, Hebei Province as the research object to discuss the difference of soil organic carbon density（SOCD） in different soils and influencing mechanism by their parent materials.According to the sedimentary environment of Holocene, the parent materials in the area were divided into alluvial-proluvial facies sediments（APFS）,alluvial facies sediments（AFS） and lacustrine facies sediments（LFS）.It was shown that there were significant variations of SOCD between soils developed in various parent materials via one-way analysis of variance, following the order AFS ＜ APFS ＜LFS.Furthermore, the texture, nutrient elements concentrations, as well as physicochemical properties of soil, were comparatively analyzed, indicating that the influences of parent material on SOC were reflected on the influences of physicochemical property of soil on vegetation growth and development, the activity of soil flora, fauna and microorganism, and on the sequestration of organic carbon.From AFS,to APFS and to LFS,soil clay fraction gradually increased, which protect SOC from being decomposed by microorganisms since SOC were subjected to be coordinated with clay minerals into organo-mineral complex.On the other hand, LFS and APFS were characterized by more abundant water and nutrients than AFS,which contributed to vegetation growth and then input of SOC.In addition, microbial activity was strengthened, whose metabolites and residues after death are crucial source of SOC,increasing the storage of SOC.Our results could provide technological supports for the conservation and utilization of SOC in the Juhe watershed.
The Zhenlongshan magmatic hydrothermal metallogenic system is located in the dome formed by a large short axis anticline in the front arc of the"mountain shaped structure"in Guangxi.The deposits(occurrence)mainly occur in the Cambrian and Devonian clastic rocks.Fluid inclusion thermometry,laser Raman,and H-O-S isotope studies were conducted on typical ore deposits.The system elucidated the source of ore-forming fluids,characteristics and evolution of ore-forming fluids,and sources of ore-forming materials for gold,silver,copper,lead,and zinc deposits around the porphyry,and preliminarily explored the genetic connections of various ore deposits(occurrence)around the porphyry.The results show that the inclusions are mainly gas-liquid inclusions,and contain more CO2 and CH4 inclusions,and occasionally contain NaCl daughter crystals.The homogenization temperature of high temperature deposit is 320～339℃,and the salinity is 8％～9％NaCl eqv;the homogenization temperature of medium temperature deposit is 280～299cC,and the salinity is 7％～8％NaCl eqv;the homogenization temperature of low temperature deposit is 160～179℃,and the salinity is 5％～6％NaCl eqv.That is,with the decrease of homogenization temperature,salinity also decreases.The δDV-SMOW and δ18 OV-PDB of quartz concentrate in-55‰～-80.1‰ and-9.1‰～-18.8‰.The H-O isotopic diagram is mainly in the range of magmatic water and tends to shift to meteoric water,which indicates that the main source of fluid in the above deposit may be magmatic water,and there is the mixing of meteoric water in the later stage.The sulfur isotope peak values are concentrated in the range of-2‰～2‰,in which arsenopyrite is mainly positive and stibnite is mainly negative.Generally,there is a relatively uniform sulfur source,indicating that the sulfur in sulfide comes from magma.The above research shows that the distribution of ore deposits(occurrence)in Zhenlongshan area has obvious zoning characteristics of magmatic hydrothermal metallogenic system.Porphyry high temperature hydrothermal deposits are developed in the pluton and its edge,and the periphery gradually transits to medium and low temperature hydrothermal deposits.The horizontal and vertical mineralization zoning model for the magmatic hydrothermal metallogenic system in Zhenlongshan area are established.
Pangkuam gold deposit is a large gold deposit that has been detailedly investigated in northwestern Laos and shows the potential becoming a super-large mineral deposit.It is of great significance to carry out research on this deposit and its surrounding area for understanding the formation and exploration direction of gold deposit in NW Laos.In this study,we investigate the petrological,geochronological and geochemical studies of volcanic rocks in Pangkuam mining area.The results show that the LA-ICP-MS zircon U-Pb ages of the basalt,chlorite hornblende andesite,and sericite hornblende andesite is 304.5±3.9 Ma,309.4±3.1 Ma,and 314.4±3.6 Ma,respectively,and these ages belong to the middle to late Late Carboniferous.These volcanic rocks show low TiO2,Ni,Cr,and high Al2O3 content.In addition,they are enriched with LREEs and LILEs but depleted in HFSEs.These geochemical characteristics tested by XRF and ICP suggest that these samples are a set of calc-alkaline andesite-shoshonite rocks and exhibit a geochemical affinity to active continental marginal arc volcanic rocks.In summary,these samples may be products of subduction and closure of the Loei ocean.The exist of intermediate-basic volcanic rock series of the Late Carboniferous may indicate that the formation of gold deposit in NW Laos needs further study,and peripheral prospecting may need to focus on more volcanic rocks.
The Neoproterozoic granitic magma activity was widespread in the Altyn orogenic belt,with formation ages around 800～1000 Ma.These magmatic events are thought to be associated with the convergence of the Rodinia supercontinent.Therefore,the study of Neoproterozoic granitic magma is of great significance for gaining insights into the evolution processes of the Altyn orogenic belt.In this study,we present precise results from petrological,geochronological and geochemical investigations of the granitic rocks from the Qiemo-Ruoqiang area in the southern Altyn block.Our findings indicate that:①In comparison to the enrichment of light rare earth elements(LREE),heavy rare earth elements(HREE)exhibit a pronounced right-leaning characteristic,accompanied by a distinct negative Eu anomaly(δEu=0.14～0.6).These rocks are enriched in large ion lithophile elements like Th,U,and K,while simultaneously showing depletion in high field strength elements such as Ba,Ti,Nb,Ta,and Sr.②Zircon U-Pb ages fall within the range of approximately 899 Ma to 915 Ma.Comprehensive studies have shown that the three categories of granitic rocks in the Qimo-Ruoqiang region were formed in a syn-collision tectonic environment,which were the products of subduction and collision between plates during the convergence stage of the Rodinia supercontinent.
There are abundant sandstone type uranium resources in Daqing Placanticline of Songliao Basin,but the metallogenic conditions are complex.In this paper,the sandstone type uranium deposit of Sifangtai Formation at the southern end of Daqing Placanticline is taken as the research object.Based on the results of three-dimensional seismic fine interpretation,the distribution characteristics,enrichment main control factors,and mineralization models of uranium deposits in Daqing Placanticline are studied.The results show that:①3D seismic data is an effective means to characterize the distribution of faults and sand bodies.②Sandstone type uranium deposit is mainly enriched in the channel sand body of the first member of Sifangtai Formation,adjacent to the transport fault connecting the deep oil and gas reservoir.③Channel sand bodies,oil and gas transport faults,and oil and gas traps are the three main factors controlling the enrichment of sandstone type uranium deposits.④The sandstone type uranium deposit in Daqing Placanticline is the result of local enrichment of uranium-bearing groundwater in coordination with oil and gas migration and accumulation,and the ore-controlling model of transport fault and oil and gas trap is established.The research results provide new ideas for the exploration of sandstone type uranium deposits in oil and gas bearing basins.
The Early Paleozoic granites in the northern part of the Great Xing'an Range are mainly distributed along the Mohe-Tahe.In this paper,geochronological and geochemical characteristics of the Luoguhe monzonite in the north of Mohe are studied.Zircons in the monzogranite is of magmatic origin,and LA-ICP-MS U-Pb dating indicates that it was formed in the Late Cambrian(486±3 Ma).The monzonite are characterized by high silicon(SiO2=62.75％～73.32％),rich alkali(AlK=8.30％～9.45％),high aluminum(Al2O3=13.97％～16.53％),low magnesium,low calcium and low titanium,with A/CNK value ranging from 0.91 to 1.10,indicating that monzonite belongs to aluminous and high potassium calc-alkaline rock series.The SiO2 content has a negative correlation with Al2O3 and P2O5.Rb,Th,U,K,Zr,Hf elements are enriched,while Ba,Nb,Ta,Sr,P and Ti are strongly depleted.In the chondrite normalized REE partition curves,LREE is enriched and HREE is depleted,which shows the characteristics of Ⅰ-type granites.Comprehensive analysis shows that the Luoguhe pluton was formed in a post-collisional tectonic setting during the late period of the orogeny between the southern margin of the Siberian plate and the Erguna micro landmass,which was transformed from compression system to extension system.
The continental red clastic sedimentary rocks are exposed in the Tanqiu-Daifang area in the southwestern part of Fuzhou Basin.Zircon U-Pb dating sets the sedimentary lower limit of this formation at 109 Ma,confirming the previous understanding that it was classified as the Upper Cretaceous.Field observations show that there are two stages of compressional tectonic deformation developed in the Upper Cretaceous strata.The first stage of NNW-trending compression was mainly characterized by NEE-trending conjugate joints and flattened calcareous concretions.Systematic measurements of finite strain of calcareous concretions in the calcareous siltstone indicate the strain type was mainly flattening strain.The second stage of NE-trending compression was marked by the development of NW-trending thrusting fractures,which cut the first stage of deformations on a small scale.Combined with the tectonic evolution history of eastern China in the Mesozoic and Cenozoic,the dynamic backgrounds of these deformations are determined:the first stage NNW-trending compression may be related to the northward migration of Indian Plate and subsequent collision with the Eurasia Plate in the Early Paleogene;the second stage of NE-trending compression may be associated with the local compressive stress field derived from the dextral strike sliping of the Ganjiang fault zone,and its dynamic background may be the eastward escape of Tibetan Plateau caused by the collision between Indian and Eurasian plates during the middle to Late Paleogene.
Hongniu-Hongshan copper deposit is the largest(distal)skarn type deposit discovered in the south section of Yidun Arc.However,there is no direct chronological evidence for the diagenetic age of ore-bearing skarn.The accurate determination of the diagenetic age of skarn is of great significance to the location of this deposit in the two stages of Mesozoic metallogenic events of porphyry in the south section of Yidun Arc.The garnets in skarn of the deposit can be divided into two stages,where the early garnets(Grt Ⅰ)are mostly found in skarn of lean ore with coarse grain structure and isotopic body;and the late garnets(Grt Ⅱ)are mostly found in skarn of rich ore with fine-medium grain structure,oscillatory zoning and heterogeneous and optical anomaly.Based on in-situ LA-SF-ICP-MS U-Pb dating and electron microprobe in-situ concentrations analysis of two stages of garnets in this paper,the U-Pb ages of Grt Ⅰ and GrtⅡ are 84.2±3.0 Ma and 81.7±3.5 Ma,respectively.The contents of major and trace elements suggest that the garnets of the two stages are classified in the andradite and grossularite series,lack of Rb,Ba,K,Sr,etc.and rich in elements Th,U and P,where Grt Ⅰ are characterized by relatively rich in andradite,high LREE/HREE ratio and high positive anomaly of Eu,while Grt Ⅱfeatures relatively rich in grossularite,low LREE/HREE ratio and no abnormal Eu.In combination of the Late Yanshanian mountain metallogenic events of regional collisional porphyry,it is deemed that the diagenetic and metallogenic period of distal skarn in this deposit is at about 80 Ma,when that mineralization is closely related to the acidic porphyry over the same period.The geochemical characteristics of garnets reveal that the dry skarn stage is characterized by a high water/rock ratio and dominated by infiltration metasomatism.The early fluid developed into a relatively closed system of oxidation,high temperature,rich iron and weak alkalinity,and the late stage formed an open system of a relative reduction,relatively low temperature,rich aluminum and acid.
Nanjing Tangquan is rich in geothermal water.It is of great significance for the sustainable use of geothermal water to reveal its supply source and genesis mechanism.The method of hydrochemistry and isotope geochemistry was taken to make the systematic study.The chemical composition of geothermal water is different from that of shallow cold water.The thermal reservoir temperature has been estimated to be 63～75℃,with a water circulation depth of 1.8～2.3 km.The geothermal fluid origins from the rainfall,and the altitude of recharge area is 321～539 m.The water age is 2046～6474 a,with shallow karst cold water mixed while upwelling,and the mixing ratio is 4％～26％.Based on these analysis,a genesis model of the study area has been postulated to be a low-medium temperature geothermal system of a convective type.It receives the precipitation from the karst outcropping area in Laoshan complex anticline,and it is gradually heated by the normal heat flow during circulating.The thermal reservoir is originally the Upper Sinian series dolomite.The cap rocks are mainly Cambrian,Cretaceous and Quaternary strata.The geothermal water flows upward in the intersection zones of the NEE-and NW-striking faults along deep circulation,and mixing with cold water in shallow,forming the geothermal anomalies.
Andesite and breccia-bearing granite porphyry samples were collected from the Baishan Formation in the Yuanbaoshan-Xirehada area of the northern Beishan orogenic collage in Inner Mongolia,NW China.Petrographic,LA-ICP-MS zircon U-Pb geochronology,and geochemical analyses were conducted to examine the Late Paleozoic tectonic evolution history in the Beishan area.The zircon U-Pb dating results suggest that the weighted mean ages of andesite and breccia-bearing granite porphyry are 300.0±2.5 Ma(MSWD=2.0,n=13)and 300.3±1.9 Ma(MSWD=1.9,n=23),respectively.These findings confirm that the stratigraphic age of Baishan Formation in the study area is Late Carboniferous.The volcanic rocks are relatively enriched in light rare earth elements and large ion lithophile elements(e.g.Rb,K,and Ba)and depleted in heavy rare earth elements and high field strength elements(e.g.Nb,P,and Ti).They exhibit geochemical characteristics related with active continental margin volcanic arcs,which indicate that the subduction history of the Paleo-Asian Ocean continued into the Late Carboniferous in the northern Beishan orogenic collage.Geochemical studies further suggest that the magma source of the andesite in the Carboniferous Baishan Formation is the middle-lower crust metasomatized by fluid in the subduction zone,and the breccia-bearing granite porphyry is mainly the product of the middle-lower crust melting,and the samples exhibit sediment incorporation.The volcanic rocks from the Baishan Formation changed from neutral and calc-alkalic rock series in the northern part to intermediate-acid or acid and high potassium calc-alkalic rock series in the southern part along the ophiolite mélange belt,indicating the southern subducted polarity of the Paleo-Asian Ocean plate.
The Erdaohezi Zn-Pb deposit is located in the middle segment of the Derbugan metallogenic belt in the Erguna block that is on the western slope of the Great Xing'an Range.Rb-Sr dating for sulfides and U-Pb dating for zircons from the andesitic porphyrite were carried out in order to constrain the mineralization age.Three endogenic mineralization stages have been identified,namely a quartz-pyrite stage(Ⅰ),a quartz-polymetallic sulfide stage(Ⅱ),and a quartz-calcite-pyrite stage(Ⅲ),of which,the second stage is the main ore-forming stage.The Rb and Sr contents of 5 sphalerites and 3 pyrites formed at the main mineralization stage in the ore belt Ⅲ vary from 0.081 ×10-6 to 2.632X10-6 and 0.661 ×10-6 to 3.186×10-6,respectively.Accordingly,Rb-Sr isotopic dating of sulfides yields a well-defined isochron age of 140.8±2.3 Ma,close to the zircon U-Pb age(138.8±1.7 Ma)of the andesitic porphyrite crosscutting or parallel to the ore body.The calculated initial 87Sr/86 Sr ratios range from 0.71025 to 0.71205,which is lower than that of the earth's crust,but higher than that of mantle.Combined with the previous studies,we suggest that the Erdaohezi deposit is a hydrothermal-vein deposit and is associated with the andesitic magmatism event(andesitic porphyrite).Additionally,mineralization occurred in an Early Cretaceous extensional setting after the closure of the Mongolia-Okhotsk Ocean.
Baiyangdian Lake is the main ecological function area of Xiong'an New Area.In order to find out the distribution characteristics of nitrogen and phosphorus in the surface sediments of Baiyangdian Lake and evaluate the pollution degree of nitrogen and phosphorus,we carried out the investigation and pollution assessment of nitrogen and phosphorus in Baiyangdian Lake.The results indicate that the total nitrogen(TN)content of sludge layer of surface sediments are 528.5～10566.5 mg/kg,and the average is 2859.91 mg/kg.The total phosphorus(TP)content of sludge layer is 425.7～2446.0 mg/kg,and the average is 789.22 mg/kg.The TN content of transition layer is 318.5～4662.0 mg/kg,and the average is 1706.7 mg/kg.The TP content of transition layer is 315.05～976.30 mg/kg,and the average is 598.97 mg/kg.The total TN reserves of surface sediments are 15.86×104 t,among which the TN reserves of sludge layer are 3.76×104 t and the TN reserves of transition layer are 12.10×104 t.The total TP reserves of surface sediments are 5.54×104 t,among which the TP reserves of sludge layer are 1.02×104t and that of transition layer are 4.52×104 t.According to the evaluation result of comprehensive pollution index method,the sludge layer of surface sediments in Baiyangdian Lake have been heavily polluted.As for the transition layer,except Shaoche Lake,which is severely polluted,the other lakes are all moderately polluted or slightly polluted.
A hydrothermal vein-type nickel-cobalt deposit was discovered in the Cambrian black rock series in Jinxiu,Guangxi,South China.The deposit is exceptionally rare and holds significant scientific and prospecting importance.This paper introduces the geological characteristics of the Longhua deposit,the rules governing ore enrichment,as well as mineralogical and geochemical investigations.The ore-bearing rock is carbonaceous mudstone in the lower part of the Cambrian Qingxi Formation,and the ore-bodies can be classified into two types:high-grade hydrothermal veins and low-grade disseminated types.Two main mineral assemblages are identified:Ni-Co-As and Ni-Co-S,occurring within the primary vein.Their distribution aligns with NWW and NNW trending faults,respectively.The primary ore minerals consist of Ni-Co arsenide,accompanied by a minor presence of sulfide,quartz and carbonate.Elemental contents of niccolite,gersdorffite,polydymite,millerite,skutterudite,bismuthite,and native bismuth minerals were analyzed using the electron probe method.Additionally,the Fe-Co-Ni ternary diagram of the primary ore minerals was examined.Based on the internal structure and paragenetic relationships of minerals,the sequence of mineral formation is elucidated,and the formation process of ore minerals can be divided into endogenic hydrothermal stage and epigenetic stage.The results of elemental mapping analysis reveal significant zonation characteristics in Ni,Co,and S elements within niccolite,possibly indicating secondary growth as the underlying cause.The hydrothermal vein-type nickel-cobalt deposit may be the product of the old crustal material recirculation before Caledonian Movement.The relationship between granites and mineralization is still difficult to judge.The supernormal enrichment of nickel-cobalt elements may mainly come from the late tectonic-fluid reformation.
Weihe basin is rich in geothermal resources.The development and utilization of geothermal resources is helpful to adjust energy structure,improve environmental protection and reduce haze pollution.Through regional geology,geophysics,petroleum exploration and geothermal well drilling,this paper makes an in-depth study on geothermal geological conditions,physical properties and reservoir evaluation in Weihe basin.The results show that the Moho surface and Curie uplift in Weihe basin have thin lithosphere and good deep thermal background;The pore types of the newly recent Zhangjiapo Formation and the Lantian-Bahe Formation were dominated by primary intergranular pores,and the pores of the Gaoling Group were not developed;The porosity of Zhangjiapo Formation of Neogene Pliocene is 3.35％～31.2％,with an average of 13.3％;permeability is 0.47×10-3～235×10-3 μm2,average 29.2× 10 3 μan2;the reservoir type belongs to class Ⅳ reservoir;the porosity of Lantian—Bahe Formation of Miocene is 5.2％～31.2％,with an average of 17％;permeability is 0.05×10 3～5684×10 3 μm2,average 326×10 3μm2;the reservoir type belongs to class Ⅲ reservoir;the porosity of Gaoling Group of Miocene is 2.5％～13.9％,with an average of 5.8％;permeability 0.01 ×10 3～11.04×10 3 μm2,average 0.75 × 10 3 μm2;the reservoir type belongs to class Ⅵ reservoir;the compaction curve of sand and mudstone shows that Zhangjiapo constituent rock has weak strength,shallow to medium burial,normal weak compaction of rock,weak consolidation semi consolidation of sediment,easy sand production,and is in early diagenetic stage B.The acoustic moveout values of the lower section of Lantian—Bahe Formation and Gaoling Group mostly deviate,and the acoustic moveout values do not change significantly with the increase of depth,which is reflected in the characteristics of medium compaction strong compaction.Due to the deep burial of Lantian—Bahe Formation and Gaoling Group,the sediments are semi consolidated sandstone,which is not easy to produce sand.Lantian—Bahe Formation and Gaoling Group are mainly in late diagenetic stage A.Through the study of Neogene thermal reservoirs,it is believed that the thermal reservoirs in the Weihe River Basin are relatively stable.Promoting the geothermal water development in this area has guiding significance for realizing the goals of 2030 carbon peak,2060 carbon neutral and double carbon.
产自欧洲、北美洲和中国三叠纪的纯信龙次亚目,是连接鳍龙类"干群"和"冠群"的关键分子,也是探讨侏罗纪—白垩纪"冠群"蛇颈龙类起源和早期演化的关键环节类群.李氏云贵龙是中国华南地区发现的纯信龙次亚目中较原始的属种,也是目前发现保存最完好、数量最多的纯信龙类,但对其头骨骨骼形态学的认识依然存在不足.贵州兴义中三叠世拉丁期法郎组竹杆坡段中新发现的一件云贵龙完整头骨化石补充了云贵龙的骨骼学信息,如额骨未愈合、枕部存在开放空间等.经详细比较,新材料可能代表了目前发现的 5 件李氏云贵龙标本中体长最大的个体,推断额骨未愈合这一特征为云贵龙特有的鉴定特征,而非个体成年与否的判断依据.新材料显示,云贵龙的鳞状骨没有后内侧支,存在开放式枕部,同蛇颈龙类相似,指示了三叠纪纯信龙类同蛇颈龙类密切的亲缘关系.
为查明共和盆地潜在氦气源岩(干热岩)稀有气体、元素地球化学和矿物学特征,笔者在共和盆地采集了与干热岩相关的花岗岩进行了稀有气体和放射性铀钍测试、扫描电镜及能谱分析,发现花岗岩中氦气含量达到 49×10-6～851×10-6,每吨岩石中氦气含量达到 0.27798～4.76992 m3,局部区段氦气含量更高.计算3 He/4 He同位素值在 7.30×10-10～2.5×10-8之间,确定该区氦气为放射性成因.共和盆地花岗岩体中常见铀钍独立矿物及分散矿物,铀含量在 0.74×10-6～38.1×10-6,钍含量在4.7×10-6～42.2×10-6.估算研究区氦生成量约 269×108 m3.在此基础上,进一步开展了花岗岩氦气储层储集特征研究,岩体中存在低密度、较高孔隙度和微裂缝发育区段,测井数据也显示花岗岩体中储集特征和脆性良好的区段,是氦气赋存的空间.花岗岩中的富铀矿物对氦气的封闭温度(27～250℃)与干热岩相关的花岗岩温度(80～236℃)基本一致,具备封存条件,估算岩体中封闭氦量为4.03×108～46.8×108 m3.岩体中浅部、深部和压裂返排液中均有氦气,深部高含量氦气存在,压裂后返排液中氦气聚集明显,初步证明了自生自储型氦气藏的存在.
