The sedimentary characteristics within the sequence stratigraphic framework of the Fourth Member of Xujiahe Formation in the middle area of western Sichuan depression were studied by using outcrops, seismic data, cores, logging and analytical testing. The characteristics showed that the Fourth Member of Xujiahe Formation is a three-order sequence,which is divided into lowstand, transgressive,and highstand system tracts according to the sequence boundary characteristics. The isochronous sequence stratigraphic framework was established and its internal sedimentary characteristics was clarified:Four types of sedimentary facies were developed, including the alluvial fan, braided river, braided river delta, and lacustrine. The characteristics of sedimentary facies distribution and vertical evolution in the sequence stratigraphic framework were also clarified. Horizontally, the alluvial fan, braided river, braided river delta, and lacustrine facies are developed in turn in the short axis provenance from the front of Longmen Mountain, while the braided river delta front deposition is mainly developed in the long axis provenance, and the short and long axis provenances are intersected in the area ranging from Hexingchang to Xinfan; Vertically, the lowstand system tract and highstand system tract are dominated by the braided river delta front, and the subaqueous distributary channel sand bodies are vertically superimposed and horizontally contiguous and widely distributed. The transgressive system tract is dominated by the shore-shallow lacustrine. Eventually, a sequence-sedimentary filling model was established. This study suggests that the subaqueous distributary channel sand bodies from the long axis provenance and the convergence areas of short and long axis provenance are quality reservoirs in the lowstand system tract and highstand system tract.

The Lower Congo basin contains a large amount of oil and gas resources, and the salt structure controls the hydrocarbon accumulation and distribution. The flow of salt rocks is irregular, therefore, it is difficult to analyze the formation and evolution of the salt structures. The former studies of the basin tectonic evolution by means of balanced sections method cannot accurately describe the formation and evolution of the salt structures in different ages. The flow of salt rock and the deformation of salt structures in the Lower Congo basin is not clear. A discrete element numerical simulation experiment was carried out, and the method of phased loading of sedimentary strata was adopted. The results are consistent with the geological conditions of the Lower Congo basin and the existing geological understanding of the basin. The results show that the formation process of the salt structure in the Lower Congo basin is mainly divided into three stages:The initial flow stage, the formation stage, and the stable stage. The main period of formation of the salt diapir structure is the Paleocene-Miocene. In the Paleocene-Oligocene period, the salt diapir structure began to form. During the Miocene period, the salt diapir structure was obvious in quantity and scale, and the Miocene was the most intensive period of salt tectonic activity. Compared with the previous research results, the main evolution stage of the salt structure is clarified based on the forward modeling of tectonic evolution process of the Lower Congo basin in this study.

The sandstone reservoir of the Second Member of Liushagang Formation in Bailian area in Fushan sag has the characteristics of deep buried,gravel developed and complex pore structures, which make it difficult to accurately evaluate the effectiveness of the reservoir. Aiming at this, the authors analyzed the core test data firstly to ensure that the main factor affecting the pore structure of the reservoir is the contact property of the skeleton particles, that is, the property of throat. Based on this research, the characterization of the reservoir effectiveness based on mercury intrusion experimental data was carried out, and the characterization of rock pore throat parameters (maximum radius, average radius, median radius, sorting coefficient) and rock porosity was constructed. The comprehensive indices of reservoir seepage and storage capacity were determined in combination with the oil test data to further establish regional reservoir classification criteria. Finally, by using the regression analysis to scale the conventional logging data, the evaluation of reservoir effectiveness using conventional logging data was realized, which is popularized and applied in actual production. The coincidence rate of logging interpretation is increased from 72% to 80%.

A large amount of metal sulfide debris, sedimentary mud, pillow basalt, inactive and active black smoker was found in the Southern Mid-Atlantic Ridge at 26°S segment (SMAR 26°S). The melt inclusions, sulfur isotopic data and copper isotopic data of collected samples, including basalt, chimney debris and massive sulfide, were well studied. The results show that the polymetallic sulfides, such as chalcopyrite, pyrite and magnetite, adhere to the bubble wall of melt inclusions in the phenocrysts of basalts, indicating that the ore-forming metallic elements and sulfur derived from the volatile-rich melt. These ore-forming elements may enter into the volatile phase and precipitate during the magma degassing. The role of sulfur in SMAR 26°S was examined by utilizing sulfur isotope. Isotope composition for pyrites in chimney debris and massive sulfides ranges from 3.0‰-3.9‰ in δ³⁴S_V-CDT, which points to a mixing process between sulfur from magmatic fluid and the sulfur from seawater sulfate. The sulfur isotopes in SMAR 26°S_V-CDT show the same variations as those of other hydrothermal vent systems on the Southern Mid-Atlantic Ridge, but all samples are relatively depleted in ³⁴S relative to other hydrothermal fields, reflecting the greater relative importance of the magmatic fluid. The monomineral Cu isotopic compositions of chalcopyrite are positive with the range of 0.171‰-0.477‰, indicating that the δ⁶⁵Cu values obtained for chalcopyrite are close to those for source rock (i.e. 0 for basalts), and characterized by slight ⁶⁵Cu-rich and low fractionation. The characteristics of the hydrothermal fluid and the source of metal are recorded by the combination data of the sulfur isotope with copper isotope and the melt inclusions. All the evidence shows the lower contribution of seawater sulfate and indicates that the ore-forming fluid and metallic elements derive mainly from magmatic-hydrothermal fluid.

The Lufilian region of Central Africa is well known for its world class copper and cobalt deposits. It also hosts uranium resources. Uranium mineralization events include continental rift and basin diagenesis (876-823 Ma), early oceanic basin formation or continental collision (720-652 Ma), and Lufilian peak metamorphism (550-530 Ma). The main metallogenic model includes the extraction of uranium from the basement and the uranium-rich rocks of Katanga Super-Group, and enrichment of uranium in tectonically modified areas. The metamorphic basement or Bangweulu basement may provide uranium sources, the thermal fluids may serve as carrier, and fractures and dome structures may serve as channels and locations. The uranium-bearing ore bodies are mostly controlled by strata and structures, and limonitization and scapolitization of surrounding rocks are of direct significance for prospecting. The study area is found to be a high-potential uranium mineralization area. The areas where the strata of the Lower Roan Group are strongly influenced by faults and thrust nappe structures with relatively developed alterations are favorable for prospecting.

In order to establish the resource evaluation system of Qianjiadian uranium Orefield, and realize the quantitative assessment of the resource of QianⅤ uranium deposit, the resource abundance model is systematically constructed by using 11 ore bed units of the Qian Ⅱ and Qian Ⅳ as model units. It is considered that the main elements controlling the amount of resources are uranium source, stracture, interlayer oxidation, reducing medium, sedimentary reservoir and sedimentary structure. Through the establishment of abundance model of the calibration units, the analogy parameters of the assessment area, the favorable mining area are delineated. The amount of Qian Ⅴ deposit resources is calculated. The arthors consider that QianⅤ uranium deposit has the potential to form a large-scale uranium deposit.

The Caledonian Pinghe composite granite pluton is located on the western edge of Baoshan block in western Yunnan, which consists mainly of monzonitic granite and porphyritic monzonitic granite. The major elements show that the total alkali (w(K₂O+Na₂O)) values are 6.89% and 7.44%, the K₂O/Na₂O values are 1.59 and 2.65, A/CNK values are 1.58 and 1.76, and the Rittmann indexes (σ) are 1.65 and 1.73; the trace and REE elements show that these rocks are rich in large-ion lithophile elements (Rb、Th) and depleted of high field-strength elements (Ta、Nb), enriched light rare-earth elements with LREE/HREE value of 1.40 and 6.43, and low-middle Eu anomalies (δEu=0.16 and 0.75). The zircon U-Pb ages of 478-476 Ma indicate that this pluton was emplaced during the Early Ordovician. 38 analyses from the two samples provide a wide range of zircon ε_Hf(t) values, and the corresponding Hf-isotope crustal model ages are 2.2-1.7 Ga. The geochemical characteristics show that Pinghe composite granite pluton is calc-alkaline and per-aluminous S-type granite formed in a stress relaxation stage after the tectonic collision of pan-african movement, and closely related to the process of extrusion, collision, and dissociation during the period of original Tethys geological event in western Yunnan. In Datuanshan, ferromanganese cerium oxide, a rare earth mineral, is found in Caledonian Pinghe composite granite pluton for the first time, which contributes the most to REO in the entirely weathered rock mass. The REO is generally not high, ranging from 279.05×10^-6 to 791.77×10^-6, overall enrichment of Y, La, Ce elements, and partial enrichment of Nd. The heavy rare earth dysprosium oxide accounts for a high proportion in all of the fully weathered rock mass, were 2.30% to 4.62%. The discovery of Datuanshan rare earth mine shows that the Caledonian granite also has a potential for the granite weathering crust type REE deposit in western Yunnan.

The intrusive rocks of Baijiazang is located in Minhe County, Qinghai Province, and the geotectonic position is located in the eastern section of Lajishan ophiolis melange belt. Through petrology, petrogeochemistry and isotopic chronology, the intrusive rocks of Baijiazang have been studied in order to determine their time of emplacement and to explore the tectonic environment. The results show that the intrusive rocks in Baijiazang are mainly composed of diorite and quartz diorite. Zircon U-Pb age obtained from diorite and quartz diorite is (472.5±1.9) Ma and (467.3±2.5) Ma, respectively, and they are consistent within the error range. Therefore, it can be judged that the emplacement age of Baijiazang rock is about 470 Ma, which is Middle Ordovician. The geochemical characteristics show that the SiO₂ content of the rock mass is 55.67%-59.04%. The value of Na₂O/K₂O was 3.35-6.14, and w (Na₂O) was higher than of w (K₂O), showing the characteristics of rich in sodium and poor in potassium. The main body of A/CNK value is between 0.76 and 1.01, belonging to the quasi-aluminum calc-alkaline series rocks. The rare earth partition curve presented a slightly right-leaning curve, where light rare earth elements were relatively weakly enriched ((La/Yb)_N=2.51-4.57), and light and heavy rare earth elements were weakly fractionated internally. The rocks were obviously enriched with large ion lipophilic elements Rb, Ba and active incompatible elements Th and U, while relatively deficient with high-field strength elements Nb, Ta, P, Ti, etc. Environmental discrimination shows that it has the characteristics of island-arc granite. The above characteristics indicate that the intrusive rocks in Baijiazang were produced at the subduction stage of the Lajishan ocean.

According to the U-Pb geochronology and geochemical characteristics of the monzonitic granite of Longtangou pluton and Luoquangou pluton in Wangjiabaozi area of Xiuyan, Liaodong Peninsula in the middle of Jiao-Liao-Ji orogenic active zone, we carried out a research. The results show that the emplacement ages of Longtangou pluton and Luoquangou pluton are (122.37±0.30) Ma and (124.37±0.91) Ma respectively, both in Early Cretaceous. According to the mass fraction of high SiO₂, low Mg, Co, Cr, and Ni, enrichment of LREE and LILE, and loss of HFSE,Longtangou and Luoquangou plutons are the products of crustal material melting. According to the mass fraction of high Al₂O₃ and K₂O, low Na₂O, MnO, and CaO, high Sr, low Y and Yb, enrichment of LILE and LREE, negative anomalies of Eu, and depletion of HREE, the monzonitic granite possesses the properties of adakite and high potassium calc-alkaline type I granite. The magma of Longtangou pluton was resulted from the partial melting of the base rock at the bottom of the thickened continental crust caused by the subduction of the oceanic crust, while the magma of Luoquangou pluton was the result of the upwelling of mantle material caused by the subduction of the oceanic crust, which led to the partially melting of the lower basalt and mixing with mantle peridotite. The research shows that both Longtangou and Luoquangou plutons are the products of collision environment caused by the subduction of the ancient Pacific plate at the age of 124-122 Ma. The transition from tectonic extrusion to tensile environment should be completed between 122-110 Ma. The lithospheric thinning and destruction began with the transformation.

Gaizhou Wanfu-Xiuyan Longtan area is located in the north margin of the North China block, which is on the Mesozoic magmatic arc belt of southeast Liaoning. It is mainly composed of two plutonic rocks. The Heilagou plutonic rocks are fine-grained biotite monzogranite, and the Qianbaogou plutonic rocks are porphyritic biotite monzogranite. The Late Triassic plutonic rocks belong to the calc-alkaline, per aluminous series. The plutonic rocks contain high content of K,Rb,and Sr,low content of Ta,Yb, and Y. The REE distribution pattern is obvious right dipping, with LREE enrichment, HREE depletion, and weak negative Eu anomaly. According to LA-ICP-MS zircon U-Pb dating, the fine-grained biotite monzogranite and porphyritic biotite monzogranite were formed in the Late Triassic ((219.8±0.7) Ma and (220.9±2.1) Ma). Based on the analyses of petrology, petro-chemistry, chronology, and tectonic environment, combined with the study of the tectonic evolution in the adjacent area, it is considered that the intrusive rocks are syncollisional S type granites, which were produced by the thickening and remelting of the silicon aluminum layer in the crust during the collision between the Yangtze plate and the North China craton.

The study area is located in the eastern part of the north margin of the North China craton, which is the intersection of the North China craton and the Xingmeng orogenic belt. The author studied the detailed petrology, geochronology and geochemistry of the Fangmu granitic porphyry in Kaiyuan area of northern Liaoning Province, discussed their formation age, petrogenesis, tectonic settings, and the thinning time of North China craton. The LA-ICP-MS zircon U-Pb dating was tested for the granitic porphyry. The ²⁰⁶Pb/²³⁸U age is (117±1) Ma, which indicates that the granitic porphyry was formed in the Early Cretaceous. The granitic porphyry is characterized by high Si, rich in alkali,poor in Mg and Ca, rich in large ion lithophile elements (e.g. K and Rb),and high field strength elements (e.g. Th, Ta, and Nb), while deplete in Sr, Ba, P, and Ti. Besides, the REE pattern shows a typical right dipping seagull shape. There is a negative Eu anomaly, which indicates that the granitic porphyry is A-type granite (A₁ subtype),and formed in the post orogenic extensional environment during paleo Pacific subduction. The magma was from the re-melting of the crustal material caused by the mantle material upwelling. In addition, the study area was a compressional orogenic environment before (156±1) Ma. Thus, we believe that the crustal thinning began in 156-117 Ma.

The content, distribution regular and enrichment mechanism of Se in the soil of Dandong area (Liaoning Province) were discussed based on the survey data of the surface soil, soil profiles,and pedogenic rocks. The results show that the content of Se in the surface soil in the study area ranges from 0.028×10^-6 to 0.910×10^-6, which is higher than the national Se average in soil. The spatial distribution of Se is affected by the strata of Liaohe Group, showing the characteristics of surficial enrichment. The Se enrichment mechanism in the soil is the following:Se derived from the metamorphic rocks of Gaixian Formation and Gaojiayu Formation, gathered and affected by the process of soil formation, in which the clay particles or iron oxides aggregated in the brown loam layer and combined with selenium; The environmental geochemistry played a certain role in the enrichment of selenium in the surface soil, and the S, N and Se in soil adsorbed and fixed with each other, which was conducive to Se enrichment in soil;In addition, Al and Fe oxides had a strong adsorption capacity to Se; A significant negative correlation occurs between Se and pH in the soil in the study area, implying the low pH value in the soil accompanied by high Se content. In general, the content of Se in soil in the study area shows obviously positive relationship with organic matter, Fe-Al oxides, S and N, which is consistent with the research results of Se in Guangzhou, Fengcheng,and Enshi.

The Late Permian to Middle Triassic is an important tectonic evolution period in the eastern segment of the Central Asia orogenic belt, which is related to the final closure of the Paleo-Asian Ocean and the sharp changes of the sedimentary environment. The well exposed Upper Permian Linxi Formation recorded the evolution history of the Da Hinggan Mountains. The fossils, including sporopollen, conchostracan, bivalves, and megaplants, are found in the Upper Permian Linxi Formation in the southern Da Hinggan Mountains, however only bivalves and a few megaplants are found in the central Da Hinggan Mountains. A total of nine genera ostracods Kemeroviana,Volganella,Iniella,Qitaina,Darwinuloides,Palaeocypridopsis,Tomiella,Darwinula and Urumqiella are found for the first time in the central Da Hinggan Mountains. The paleo-zoogeography of the ostracods assemblage is closely related to those Late Permian ostracods assemblages, which are widely distributed in Russian platform. The evidences of the fossil assemblages and their preservation suggest that Linxi Formation was deposited in a continental lacustrine environment.

The ancient and old landslides of terrace type are often greatly influenced by external geological processes and human activities, and the morphological characteristics of landslides are seriously damaged or even disappeared;Therefore,it is difficult to determine their existence by remote sensing technology and general engineering geological mapping;However,they are potential hazards in constructions and operations. In order to identify the ancient and old landslides with unclear shape, the typical material structure caused by the shear failure of the terrace can be traced back from the evolution of the terrace material structure. For example, the broken stratigraphic structure, abnormal directional gravel alignment, augen structure of friction mirror and mud coated particles can be used as the basis to precisely identify the landslides. The criss-crossing tracking method of an engineering geological mapping along gully is used to determine the longitudinal range and sliding surface shape of landslide body, and then the plane range and distribution of landslides at each level and block are deduced according to the geomorphological features. Finally, the conclusion is verified and corrected by point exploration engineering. This terrace landslide identification procedure can be summarized as "recognizing geomorphological anomaly, tracking along the gully, surface inference,and point verification". Combined with the characteristics of each stage of the linear engineering investigation and design, the identification steps of terrace landslide during the preliminary work of linear engineering were put forward and applied successfully in the construction project of Lin-Wei expressway.

In order to understand the failure process of landslide dam, nine sets of flume model experiments were conducted, the depth erosion and tracing of dam breach was further discussed, and the relationship of moving velocity of up-tracing point and breach depth was also analyzed. The results indicated that the angles between the erosion layer and the base bed were changing during the dam failure of non-cohesive landslide dam; The locations of up-tracing and down-tracing point were unfixed,but they could not move to the dam heel; When the slope of the upstream and downstream face slope increased to a maximum of 1:1.5, the ratio of the maximum distance from down-tracing point to downstream toe of the dam to the length of the dam along the flow direction (reflecting the final relative position of the down-tracing point) was correspondingly reduced to the minimum values of 0.24 and 0.18; When the relative scale of the dam reduced from 1 to 1/2, the value of x_p^*/x_d^* was correspondingly increased from 0.38 to 0.47. The dimensionless moving velocity of up-tracing point was constantly changing; There was a time delay of the peak breach water depth relative to the peak moving velocity, and the dimensionless delay time was about 0.04.

In order to investigate the variation of pile end resistance with penetration depth in silt and silty clay, a spoke pressure sensor was installed at the pile end of the test pile P1, and a fiber grating sensor was installed at the test pile P1 and P2 200 mm away from the pile end. Two different test techniques were used to monitor the pile end resistance during the on-site penetration of two closed-end prestressed high-strength concrete pipe piles. The test results show that the resistance of the pile end is closely related to the change of the soil layer. The harder the soil layer is, the greater the resistance of the pile end is. When the pile end enters the silt layer from the silty clay layer, the pile end resistance increases significantly. The pile end resistance in the silt reaches twice of that of the silty clay layer. During the whole penetration process, due to the difference of soil layers at different locations, there is a certain difference between the pile end resistance of P1 and P2. The position difference of the same soil layer has a great influence on the pile end resistance. Below the ground 1.50 m, the difference of pile end resistance between P1 and P2 reached 89.29 kN; While below the ground 3.50-4.50 m, the difference between the pile end resistances of the two piles is small.

In the view of the effect of average particle size on the shear behavior of sand, a meso-level research was carried out by indoor tests and discrete element simulation methods. Based on the results of three direct shear tests with different average particle size, the PFC (particle flow code) particle flow model reflecting the characteristics of sand shear test was established to study in detail the variation characteristics and laws of soil sample changes, force chain network, porosity, coordination number,and other microscopic structural parameters of sandy soil with different particle sizes during the shear process;And the effect of particle size on the macroscopic shear behavior was analyzed from the microscopic perspective. The research results demonstrate that there are significant differences in the sand shear meso-parameters with different average particle sizes, and the differences are mainly reflected in the shear zone. The effect of average particle size of sand on its shear mechanical properties is mainly reflected in its shear strength and dilatancy deformation. The larger the average particle size is, the higher the shear strength is,and the more obvious the dilatancy effect is. There is a certain difference between the soil particle movement law and the morphological change characteristics of the shear zone during the shearing process:the larger the average particle size is, the larger the proportion of up span particles in the shear band is, and the larger the thickness of the shear band is.

Because of many risk factors, the stability of deep foundation pit of metro is highly demanded during excavation. Especially in the water-rich gravel stratum and near the existing metro line, it is extremely necessary to make an accurate evaluation of the stability of foundation pit in excavation. The authors took Fengxi station deep foundation pit project of Chengdu Metro Line 17 as the research object, by using the combined weight obtained by using the subjective weight determined by AHP and the objective weight determined by entropy method with the grey correlation method, and objectively evaluated the stability of foundation pit in the excavation through the fuzzy comprehensive evaluation of the monitoring data of the sections around the foundation pit. The evaluation results show that the importance of foundation pit stability to each monitoring project from large to small is horizontal displacement of pile on the top (0.29), ground settlement (0.24), building settlement (0.19) settlement of pile on the top (0.18),and internal support axial force (0.10). The comprehensive evaluation result of the foundation pit stability is very good. The evaluation model can provide reference for the construction of deep foundation pit and risk control in Chengdu area.

In order to clarify the frost damage mechanism of horizontal frost heaving displacement to the inner and outer waterfront arch parapet in the seasonal frozen soil regions, and test the effectiveness of the anti-freezing device with isolation layer, some inner and outer structures in Changchun were taken as the research objects. In comparison with the three arch parapet structures including inner, outer, and experimental inner with isolation layer anti-freezing devices, the horizontal displacement states were observed and measured by steel rule in the three observation years (20101110-20110531, 20131110-20140531, 20171110-20180531) in cold periods. It turned out that there were inward horizontal frost heaving displacement frost damages, such as, tilt and crack in the inner structure. All the inward horizontal displacement curves developed a "half hump" trend according to the temperature;Corresponding to the continuous cooling-continuous low temperature-continuous heating-positive temperature period in the observation year, the inward horizontal frost heaving deformation showed the residual displacement movement of decreasing-increasing-decreasing-stabilizing caused by generating-growing-weakening-disappearing of the horizontal frost heaving stress. There was minor outward displacement to the outer structure, and all the curves of such a displacement showed wavy without any occurrence of frost damages. The horizontal frost heaving stress of the ice convex arch pushed the outer arch structure to compress the frozen soil concave arch to form the outward horizontal frost heaving displacement, which restricted its development. There was no horizontal displacement frost damages in the experimental inner arch structure. The inner horizontal frost heaving displacement is 83.92% less than that of the natural inner structure and 51.74% less than that of the outer structure. This result demonstrates that the anti-freezing device with isolation layer can prevent the horizontal displacement frost damage effectively.

In order to accurately evaluate and plan the allowable exploitation quantity of geothermal water in Tangshan area, Nanjing, and to predict the changes of water level and temperature under the planned mining conditions, based on a full understanding of the hydrogeological information of geothermal water system, a hydrogeological conceptual model in Tangshan area was generalized,and a three-dimensional coupling mathematical model of unsteady seepage and heat transfer of groundwater was established in this area. The allowable exploitation quantity of geothermal water and the changes of water level and temperature were predicted under the condition that the drawdown is no more than 50 m. The results of simulation show that the allowable exploitation quantity of 14 existing geothermal water wells in Tangshan varies from 125.0 m³/d (R11) to 1 450.0 m³/d (R08). The total allowable exploitation quantity of geothermal water is 3.08×10⁶m³/a. With the decrease of geothermal water level, its temperature rises 2-3℃ per year on average.

The traditional Theis wiring method cannot use all the pumping test data, the manual wiring efficiency is low, and the parameter calculation is greatly affected by human subjective factors. In order to solve these problems, based on the pumping test data and Theis formula and superposition principle, the maximum value of Nach-Sutcliffe efficiency coefficient of theoretical calculation drawdown and measured drawdown was taken as the objective function. Through Matlab software programming, the hydraulic conductivity coefficient T and water storage coefficient S are traversed within their corresponding ranges by using the ergodic search algorithm, by which the automatic and accurate solution of hydrogeological parameters is realized. The ergodic search algorithm was applied to determine the hydrogeological parameters of two pumping test cases,and the results were compared with those of the traditional methods. The results show that the results obtained by ergodic search algorithm are similar to those obtained by traditional methods,which shows that the ergodic search algorithm is effective and reliable in solving hydrogeological parameters. The values of Nach-Sutcliffe efficiency coefficient of theoretical calculation drawdown and measured drawdown obtained by the ergodic search algorithm for the two pumping test examples are 0.996 5 and 0.970 8 respectively, which are closer to 1.000 0, indicating a better fitting degree compared with the parameter results obtained by the traditional methods.

In the process of wastewater treatment in an electroplating park, due to the difficulty of the enterprises in the park to completely separate the quality, the complex breaking of the wastewater treatment is not complete, the hypophosphite and cyanide are complex and difficult to degrade. At the same time,the concentrate has to be treated by advanced treatment, as after the treatment, the contents of metals, total phosphate and nitrogen are still not meet the drainage industial standard. According to the typical water quality and water quantity characteristics of electroplating wastewater in enterprises,the authors studied and designed the advanced treatment technology of innovated CAFE(catalysis-adsorption-filtration-exchange),and introduced in detail the treatment technology, the process,the main equipment and the related design parameters of each process,and further carried out the actual treatment of electroplating wastewater in an electroplating industrial park in Nantong. The practical application shows that the waste water treatment operation of the design scheme is stable. The average concentrations of COD_Cr,NH₄-N,total chromium,hexavalent chromium, and total nickel in the final effluent are 34.00,5.41,0.29,0.03, and 0.05 mg/L,respectively,which are far less than the discharge standards of electroplating wastewater and meet the requirements of advanced treatment of electroplating wastewater. Based on cost-benefit analysis,the treatment has a good market prospect.

Noise is one of the bottlenecks that restrict the application effect of electromagnetic prospecting. Understanding the characteristics of electromagnetic fields is primary for an electromagnetic research in strong noise areas. Based on the investigation of interference sources and a large amount of measured data in Lu-Zong ore concentration area, we summarized the main types of electromagnetic noise sources in strong noise areas, and the distribution characteristics of the noise-containing electromagnetic fields in time, frequency,and space domain by comparing and analyzing various types of electromagnetic field data with different conditions. The results show that the noise sources in Lu-Zong area can be classified into different forms; the data of the noisy electromagnetic fields often have significant morphological, amplitude, structural, and correlative characteristics in time domain; the spectrum figures often show different time and frequency band characteristics; the frequency domain responses often show distortion in certain frequency bands, and the "near source" distortion is the most typical one. The spatial distribution of noise influence is related to the types of field sources, observation orientations, and underground structures. According to the characteristics of noise data, the pertinent processing algorithm or research direction is pointed out, which provides a reference for the application of electromagnetic methods in strong noise areas.

Electrical anisotropy is ubiquitous in nature, especially in some sedimentary basins, where some rock layers underwent compaction and metamorphism,showing a strong anisotropic conductivity,on which a positive and negative interpretation is more reasonable and accurate. The forward calculation of magnetotelluric anisotropy by adaptive finite element method was used to simulate the response of horizontal, vertical and oblique anisotropic media at different deflection angles and spindle resistivity in this study. The results show that the adaptive finite element can obtain a reasonable mesh under the control of the posterior error, and make the calculation result closer to the analytical solution; In anisotropic media, the apparent resistivity and impedance phase of the magnetotelluric TE polarization mode is independent of the resistivity perpendicular to the plane; In a two-dimensional anisotropic structure, the magnetotelluric TM polarization mode response is always determined by the resistivity component on the spindle in the y-axis direction.

Based on the digital waveform data of the regional seismic network, we inverted the seismic moment tensor solution for the Songyuan M5.1 earthquake by using the ISOLA method. Also,we inverted the stress field of the focal mechanism of the M_L>2.5 events in the aftershock sequence by FMSI method. The study results show that the Songyuan M5.1 earthquake has a moment magnitude of M_w 4.9, centroid depth of 7 km, and double couple components of 91.5%. The azimuth and plunge of P-axes are 76° and 3° respectively, and those of T-axes are 166° and 16° respectively. The reduced stress tensor shows that the azimuth and plunge of σ₁ are 88.0° and 0.9°, those of σ₂ are 178.2° and 9.6°, and those of σ₃ are 352.5° and 80.4° respectively, which agree with the region stress field. We suggest that it is the region stress field that triggered the Songyuan M5.1 earthquake, which occurred on the second Songhuajiang fault near the source region.

Paleo-Channels play an important role in reproducing changes of paleo-climate and paleo-ecological environment. The data of polarimetric synthetic aperture radar (SAR) record the backscattering information of ground objects in the form of scattering matrix, which can be used to effectively identify the hidden paleo-channels information. The Western Songnen Plain was taken as the research area, and the Sentinel-1 VV-VH dual-polarization data were selected as the data source. The H/α VV-VH dual polarization mode of Sentinel-1 was decomposed, and a two-dimensional H/α plane composed of scattering entropy H and scattering angle α was constructed. Based on the fact that there is bulk scattering in the paleo-channel filled with sediments and secondary scattering at the bottom interface of the paleo-channel, and the volume scattering power is greater than the secondary scattering, it is confirmed that the paleo-channel scattering type belongs to the multiple scattering of high entropy H/α plane. Combined with the Sentinel-2 image, the paleo-channel information in the study area is finally extracted. The results show that the paleo-channel information without obvious features in the Sentinel-2 image can be extracted by the H/α decomposition in the VV-VH double-polarization mode.

The Xinchengzi basin in Inner Mongolia is located in Zhalantun volcanic-type uranium deposit prospecting area in the southern end of Da Hinggan Mountains. The Mesozoic volcanic activities in the basin were frequent and intensive, and regional fault structures were developed. The volcanic-type uranium is the main type of mineralization in this basin. So far, one volcanic-type uranium deposit, two uranium mineralized spots, and twenty mineralization anomalies were found, which indicate that there is great metallogenic potential in this basin. The bedrock of the research area is well exposed, which is conducive to carry out the remote sensing for uranium deposits exploration. In the study area, the author used the remote sensing data to interpret the structure and extract the alteration information. According to the data of GF-1, the study area is characterized by four sets of linear structures of NE, NW, near EW, and near NS. According to Landsat ETM data, the alteration information, such as iron stains and hydroxyl groups, was extracted to narrow the ore prospecting area. In addition, the geological survey and drilling were carried out. Finally, according to the multi-source geo-information, four metallogenic prospecting areas (Husitaibei, Bayanerdeng, Wujianfang and East Renjiayingzi) were delineated. One polymetallic industrial hole in Husitaibei and two uranium industrial holes in Wujianfang have been verified by drilling.

Geochemical exploration research involves a large amount of sampling work, which is extremely difficult in inaccessible terrain with harsh working environments. The authors propose a geochemical inversion model with remote sensing images by using extreme learning machine (ELM) to alleviate the difficulty of ore prospecting in the areas with insufficient regional data. The partial least squares regression (PLSR) method is used to select the remote sensing image features which are highly correlated with geochemistry data. In this model, the nonlinear relationship between the geochemical data and the remote sensing images is established using ELM for getting unknown geochemical anomalies, after which the ore prospecting work can be further promoted. In the experiment, 1:200 000 soil geochemical data of Cu element and the Landsat 8 OLI remote sensing images were used for the inversion analysis. The experimental results showed that the anomalous distribution obtained by the ELM-based inversion model had a good correspondence with known ore spots, which verified the effectiveness of the proposed model.