Based on measured properties, such as physical properties of log interpretation and oil production tests, the petrophysical parameter cutoff and depth of medium-deep effective reservoirs of Paleogene in the southern Raoyang sag are determined by distribution function curve method, test method, oil production test method, and the fitting formula of petrophysical parameters. Further, the porosity difference is introduced combining with the analysis on the characteristics of sediments, diagenesis, and reservoir pressure of the medium-deep reservoirs in southern Raoyang sag; and the controlling factors of effective reservoirs are discussed. The results show that the subaqueous distributary channel and estuary bar of fan delta front subfacies are suitable for the growth of effective reservoirs; while the properties of delta-front sheet sand and inter distributary bays are weak, where less effective reservoirs are developed. When the thickness of sand is greater than 3 meters, the sand could be developed into an effective reservoir. Compaction and cementation are the main factors to decrease porosity and permeability of reservoirs; while dissolution increases the secondary pores, and in turn, makes the physical property of reservoir better. The existence of overpressure promotes the development of effective reservoirs.

The comprehensive methods, including core observation, thin-section examination, physical property analysis, mercury porosimetry, and oil test, have been used to systematically study the characteristics of the low permeability reservoirs of Chang 6₃ Member in Huaqing area, analyze its origin, and discuss the main controlling factors of high quality reservoirs. The results show that the thick massive sandstones of the reservoirs of Chang 6₃ Member in Huaqing area are mainly composed of vertically stacked sandstones that are formed by liquefied sandy clastic flow. The rocks mainly consist of arkose with minor lithic arkose. The reservoirs are characterized by the low to particularly low porosity and permeability. The pores of the reservoir are primarily intergranular pores, secondary erosion pores, and intercrystalline micropores, the so called micro-fine throat structures. The formation of low permeability reservoirs of Chang 6₃ Member in Huaqing area is mainly controlled by the high matrix content, low textural, and low compositional maturation; and it is further strengthened by compaction. Under a suitable water dynamics with low mud content, a thick sandstones could develop into a high quality reservoir.

As a result of the sedimentary evolution, the sand bodies and distribution of the fan delta reservoir developed in the first and second member of Shahejie Formation in Shijiutuo uplift are paleo-geomorphically different. The reservoir prediction is difficult. The authors carry out the paleo-geomorphology reconstruction by analyzing the control action of the fault movement on the paleo-geomorphic pattern, study the relationship between the paleo-geomorphic unit and the sedimentary system, explain the control of paleo-geomorphology on sedimentary system, and reveal the sedimentary process. On the above, seismic attributes and the distribution characteristics of the fan delta, the difference of fan delta sedimentary system development is analyzed. Finally, the control action of the basin edge valleys and paleo-geomorphology on provenance is figured out. A depositional model, "large valleys correspond to large fans and small valleys correspond to small valleys", is established. Also, the depositional pattern of the fan delta located in slope zone and the control mechanism of sands distribution are determined. The method can predict a reservoir effectively in oilfield exploration and development stages.

The opinions to the sedimentary facies in the western Sulige gas field were so different that they lead to the big difficulty to forecast the sandbody distribution in exploration and development. We studied the sedimentary facies through adopting the techniques and methods of stone characteristics analysis, sedimentary structure description, and fossil observation; revealed sedimentary sequences of outcrop from Chengjiazhuang based on the facies logging and seismic reflection related to fluvial facies researched by predecessors in the Lower He₈ Member. The research results show that the braided river deposition is the main facies type of the Lower He₈ Member in Western Sulige Gas Field. In our opinion, the frequent climate change from dry to humid is the controlling factor,which resulted in the large thickness of sandbody, strong heterogeneity, and lateral variation of reservoir.

The discussion on three-dimensional geosteering technology for the horizontal wells in Sulige gasfield provides some new ideas and technology for the development of large-scale horizontal wells. The analysis of horizontal well three-dimensional geosteering technology is carried out through obtaining true dip via three dimensional comparison with apparent dip in two-dimensional, precise strata correlation,and reservoir distribution, recognizing the braided river facies of micro-facies and characteristics, and analyzing the regional geological background and distribution of sand bodies. The He₈ Group braided river sub-facies mainly include channel-filling, channel bar, abandoned channel, overbank deposit. Based on the analysis of sedimentary microfacies, the three-dimensional geosteering technology can effectively guarantee the horizontal drill encounter rate. The three-dimensional geosteering technology is developed based on three dimensional comparison, sedimentary microfacies scale, and their characteristics. It can expand and extend the development of the horizontal well geosteering methods and techniques,and effectively promote its application.

Under certain geological conditions, low-mature gas can accumulate to a gas reservoir. In the past, the evaluation of terrestrial low-mature gas source rock was only focused on the study of the physical and chemical properties. Due to the limitation of the current exploration and analyzing techniques, it is difficult to objectively evaluate the potential of the low-mature gas source rocks and their relative merits as source rocks. After reviewing the current research status of terrestrial low-mature gas source rocks, we build a new evaluation index system through analyzing 10 influencing factors and the range of each parameter. Based on the above, we build a new evaluation model for the terrestrial low-mature gas source rock by fuzzy analytic hierarchy process(AHP). With this new evaluation model, we can avoid the paradox in the evaluation of the low-mature gas source rocks and the blindness of selecting parameters; also we can improve the evaluation efficiency. The evaluation results agree with the analysis in Urengoy gas field. Based on the evaluation, the source rocks of Achimov, Bazhenov, Vasyugan, and Pokur are low-mature; Neocomian's and Tyumen's are in between of low-mature and mature; while Tampey's is mature. The method is provedto be practical and reliable in application.

The rare earth elements (REE) and trace elements are analyzed by ICP-MS for the 104 pieces of Paleogene fine clastic rock samples from Lanping basin, Yunnan Province. ∑REE is relatively high;and the differentiation is significant between LREE and HREE.LREE is abundant; while HREE is depleted. LREE is heeling rightward obviously; while HREE is even, with Eu and Ce negative anomaly. The tectonic background of Paleogene fine clastic rock in Lanping basin is studied in detail through an analysis on the geochemical characteristics of REEs and trace elements, sedimentary tectonic setting discrimination diagrams with w(Zr)-w(Th), La-Th-Sc, Th-Sc-Zr/10, and a variety of crossover methods. The property of source rock is also analyzed by La/Th-Hf and La/Yb-∑REE discrimination diagrams. The results show that the Paleogene clastic source rocks in Lanping basin are mainly felsic rocks derived from the upper crust, and mixed with a small amount of andesitic source. These results show that the source rocks formed tectonically in an environment of early continental arc which transferred later to a passive continental margin.

In order to define the reasonable and preferable mine area for the application of oceanic Co-rich crust mine,after the modal of mining proposed by the International Seabed Authority(ISBA),based on the public dredge hauling surveying data of Co-rich crust on Govorov Guyot and the posterior probability chart of crust potential resources from the Weights-of-Evidence-Modeling ,considering the features of the regional Co-rich crust distribution of Pacific seamounts,the prospective area of Govorov Guyot crust resources firstly and then seven clusters (a total of 100 cobalt-crust ore blocks) were delineated by man-machine interactive method for delineating mining areas based on meeting regulation requirements of ISBA.The amount of wet crust resources of Govorov Guyot is calculated to be 69 487.6×10⁴ t according to water depth. 100 crust blocks are mainly distributed on the slope,and their amount of wet and dry crust resources are calculated to be 14 092×10⁴ t and 9 789.35×10⁴ t respectively, including 1 961.3×10⁴ t manganese,10.17×10⁴ t copper, 54.06×10⁴ t cobalt, 34.87×10⁴ t nickle. These figures show that the scale of Govorov Guyot is very large, and its Co-rich crust resource prospect is valuable for further survey and exploitation.

Jiaochong Au-S deposit is located in Tongling ore concentration area which is in the middle and lower reach of Yangtze River. The ore bodies are mainly existed in the limestone of Qixia Group in Early Permian. According to the research of the field geological characteristics and ore composition, Jiaochong ore was fromed in the three phases: early quartz stage, middle quartz-sulfide stage, and late calcite stage. Through the detailed petrographic observation and microscopic measurement to the quartz and calcite of different ore-forming stages, the fluid homogenization temperatures fall into the three scopes: 410-440 ℃, 320-350 ℃, and 260-320 ℃ correspondingly, showing a downward trend from the early quartz stage to the late calcite stage. According to the formula calculation, the metallogenic depth is about 1.5 km; and the mineralization pressure is 400×10⁵ Pa. Fluid boiling action was the main mechanism of metal sulfides precipitation. Trapping pressures of fluid inclusion are used to estimate the ore-forming pressure and depths, so as to provide a theoretical basis for deep prospecting prediction.

The newly discovered Chagele skarn-porphyry deposit is located in the Middle-Gangdese metallogenic belt. This study focuses on the zircon U-Pb age of the ore-bearing porphyry and molybdenite Re-Os, the whole rock major elements, trace elements, and the Sr-Nd-Hf isotopic data of the ore-bearing rocks in Chagele deposit. The zircon U-Pb age of the ore-bearing porphyry changes from 64.6 to 62.9 Ma, which represents the magmatic crystallization age. The Re-Os isotopic age shows that the deposit was formed at (62.3±1.4) Ma, which is consistent with the magmatic age in the study area. Combing with the extensive volcanic event of Linzizong Group, these new data suggests that the different scales of mineralization were formed at different stages in the entire collision between India and Eurasia continent. The ore-bearing porphyry of Chagele deposit has high contents of SiO₂, K₂O, Rb, Th, and U, coupled with low contents of TiO₂, P₂O₅, negative anomalies of Nb, Zr, variable ε_Hf(t) (-7.02~-1.27), and ancient T^C_DM (1 093~1 419 Ma). In comparison with the Gangdese continental crust composition, the ore-bearing porphyry is high in ε_Nd(t) (-6.64~-5.79) and low in (⁸⁷Sr/⁸⁶Sr)_i (0.711 813~0.717 307). These geochemical features indicate that the porphyry of Chagele deposit is similar to the peraluminous feature of S-type granite. The above discussion suggests that the Paleocene magmatism and mineralization in the middle section of the Middle-Gangdese metallogenic belt could be formed through partial melting of the ancient crust materials of Gangdese micro-continent accompanying with fractional crystallization, which was probably induced by upwelling of mantle-derived magma in the main collision between Indian and Eurasia continent.

The composition of REE in ore bearing rocks of Nanchuan-Wulong area indicates that the total amount of REE is high, and the partition modes in the bauxite-bearing horizons and in the underlying Silurian Hanjiadian Formation are quite consistent. This implies a genetic relationship between the bauxite source and Hanjiadian Formation. The values of LREE /HREE are great in the majority samples. It is obvious that the light rare earth elements are strongly enriched; while the heavy rare earth elements are depleted to varied degrees with Eu middle negative anomaly.The content of REE in the ore bearing rocks changed only slightly after deposition. Based on the characteristics of rare earth elements and the related parameters, the environment of bauxite ore bearing rock series and their material sources are deduced as followings: ore bearing rocks were formed mainly in continental facies with some marine sediments; based on Ce, Eu anomalies, acidity of paleo water media was weak; ore bearing rock series were mainly formed in an oxidation environment, which was profitable for the formation of bauxite. Material sources of the ore bearing rock series are diversified; both silty shale of Silurian Hanjiadian Formation and Carboniferous limestone of Huanglong Formation might be the source of material.

Kawabulak complex is distributed within Kawabulak-Aktagh area in the east section of Central Tianshan block, and extended nearly latitudinally along the Kawabulak fault. We present zircon LA-ICP-MS U-Pb chronology and LA-MC-ICP-MS Hf isotopes analyses of diorites that comprise the main parts of the intermediate and basic rocks of the complex. The zircons of diorites are mainly euhedral and hypidiomorphic texture with clear rings and high Th/U ratios(>0.40). The Th and U contents show a well positive correlation. This indicates that the zircons are typically from magma. The results show that the diorites intruded during the Late Devonian period with the ²⁰⁶Pb/²³⁸U weighted average age of 375±1 Ma (MSWD=0.081). Zircon Hf analyses show a relatively homogeneous isotopic composition; the initial Hf values fall in between 0.282 655-0.282 747 and positive ε_Hf(t) values of +4.0-+7.2 with a depleted mantle mode age (from 714 to 842 Ma). Combining with previous studies, we suggest that the diorites from Kawabulak complex were formed through a partial melting of depleted lithospheric mantle.

The REE geochemistry of four groups of samples (the regional stratigraphy, ore-hosting rocks, altered rocks, and uranium ores) were analyzed by using ICP-MS method to investigate the genesis of the uranium bearing granite in Danfeng area, North Qinling. The different groups of samples show significant similarity in LREE-enriched REE patterns and negative Eu anomalies. This indicates that the ore-hosting rocks and regional strata were formed in a typical island arc tectonic environment. Besides, altered rocks and uranium ores inherited abundant REE geochemical characteristics from the ore-hosting rocks. The rocks and uranium ores with narrow range of Y/Ho ratios between 25.09-33.46 were derived from the same source. In addition, uranium ores are characterized by highest ∑HREE,and HREE contents correlate positively with uranium ores grades, which is regarded as a clue to a simultaneous transportation of HREE and U.

Located in the eastern part of the Yangtze plate, the tectonic deformation of the Lower Yangtze is of geological significance. Based on the regional geological data, seismic data, well logging, and geophysical data, the stratigraphy and faults are finely interpreted, and two regional geological profiles are established throughout the study area, namely Suqian-Shaoxing profile and Lianyungang-Suzhou profile. The Lower Yangtze region is divided into 6 level one tectonic deformation units, followed by Subei-Jiaonan orogenic belt, Subei thrust area, north and south thrust belt, Sunan thrust area, Zhebei thrust area, and Jiangnan orogenic belt, and it can be further divided into 14 level two tectonic deformation units, which clearly represent the Mesozoic-Cenozoic tectonic deformation of the Lower Yangtze region. There are three typical tectonic deformation styles out of the two profiles, including compression, extension, inversion, which can be divided into 5 sub-classes and 10 small classes.

The Dayaoshan metallogenetic belt is a gold-polymetallic ore-bearing genetic belt extended in nearly EW, and exists in the Cambrian weakly metamorphic rocks.In this metallogenentic belt, different granitoids are dominated, including granodiorite, granite porphyry, monzonite granite, and granodiorite porphyry. They appear as dikes or pipes in the field, a results of magmatic intrusion. The authors studied the chronology of these granitoids in the plutons of Dawangding, Da'an, Gulong, Dacun, Sheshan, and Siwei by using LA-ICP-MS. In combination with the previous geochronological data, the geochronological framework of the granitoids in Dayaoshan metallogenentic belt is reconstructed. The results show that the granitoids in Dayaoshan metallogenetic belt were mainly formed in Caledonian (444.8±2.5 Ma), Early Yanshanian (Jurassic; 164.2±2.8 Ma), and Late Yanshanian (Late Cretaceous; 96.6±1.1 Ma). The gold and polymetallic mineralization ages are consistent with the ages of these granitoids.

Kaladawan area of the eastern Altun Mountains of Xinjiang is tectonically located between the NE-trending Altyn Tagh strike-slip fault and the EW-trending northern Altyn Tagh fault, where the intermediate-acid intrusive rocks are wildly distributed. The granodiorite in the north of Highland 4337 is selected to study the tectonic evolution of the Kaladawan area. The geochemical data of the intrusion suggests that it is high-K calc-alkaline I-type granitic rock which was likely derived from a partial melting of the intermediate- to high-K meta-andesitic-basaltic rocks under high pressure. Zircon U-Pb age obtained by SHRIMP from the granodiorite is (494.4±5.5) Ma, implying that it was emplaced in the Late Cambrian period. Integrated with geochemistry, trace element discrimination, geochronology, and regional background, it is inferred that the granodiorite was formed in a subduction-related active continental margin (continental arc). In combination with the previous studies of magmatic activity in Kaladawan area, we suggest that the central Altun block were developed in Early Paleozoic into an active continental margin (continental arc), and a magmatic belt were caused by the southward subduction of an oceanic crust to central Altun block during Late Cambrian to Early-Middle Ordovician. Compared to the ages of the intermediate-acid intrusive rocks of north Altyn Tagh area, the evolution of western and eastern parts is different. The west of north Altyn Ocean subduction lasted relatively longer than the east,and the syn-collision stage in the east was earlier than in the west.

A factorial kriging analysis was conducted on seven heavy metal elements, Cd, Ni,Cu,Zn,Pb,Cr,As, of 388 surface samples collected from western Pearl River Estuary to study the spatial structure characteristics of the heavy metal elements, identify and separate spatial principal components at different spatial scales, and discuss the provenance of heavy metal elements and the influencing factors.The results show that the heavy metals exist spatially in three scales: nugget scale, spherical structure with a range of 60 km (local scale), and spherical structure with a range of 160 km (regional scale).According to the distribution of the regional factor(F₁ and F₂) score, high-value areas of F₁(Zn,Cr,Ni,Cu)and F₂(As)at local scale reflect "bull-eye like" distribution in estuary and harbor of coastal land. This suggests the potential anthropogenic pollution area of Zn,Cr,Ni,Cu and As. The eastern coast of Leizhou Peninsula is most likely the area of heavy metal pollution. The spatial distribution of the heavy metal elements at local scale is dominated by the local terrain or current; and their different spatial distribution between As and Zn,Cr,Ni,Cu is due to their different element geochemical behavior. The regional factors F₁(Zn, Cr, Ni)and F₂(As)at regional scale indicate the influence of terrigenous parent rock,in which Zn,Cr,Ni are derived primarily from the parent rock from the mainland of South China;while As is derived primarily from the parent rock of Hainan Island.The high-value areas of F₁ and F₂ at regional scale show "slice-like" distribution extending from coast towards deeper sea overall in NNE direction; which is due to sea-level changes and the regional ocean circulation in NNE direction.

There are many loose slopes existed in the seismic disturbance area. Landslides and debris flow can be easily induced by a heavy or concentrated rainfall. The hazards often occur in a form of chain in an earthquake region with a severer harm than the one caused by a single disaster. In order to evaluate the geological hazards effectively, we regard the landslide and debris flow as a disaster chain and conduct the analysis synthetically. A coupled model has been developed to assess the hazard degree of debris flow induced by the different 24 h precipitation at watershed level in Baishahe watershed of Dujiangyan City in Sichuan Province. The model comprises of a landslide susceptibility evaluation model, a stability model, a hydrological model to predict unstable slopes and determine the amount of landslides to be involved, and a statistical model to evaluate the hazard degree of debris flow gully by selecting debris flow volume, frequency, basin area, main gully length, height difference, cutting density, and the ratio of unstable gully bed as the evaluation parameters. The results show that the volume of loose material involved in debris flow increase with the intensity of rainfall. However, when 24 h rainfall is over 200 mm, the hazard degree of debris flow does not change any more. Among the 17 debris flows,four debris flows are middle hazardous, twelve debris flows are high hazardous, and one debris flow is very high. It indicates that the potential geological hazard is quite serious in the study area. During the rainy season, 17 debris flows might concentratedly outbreak; which would directly threaten the nearby human lives and properties. The protection engineering and early-alert should be set to eliminate the hazards caused by the debris flows in comply with the high level fortification standard. By the way, it's necessary to take landslide and debris flow as a disaster chain to make the hazard assessment.

Giant landslides (1×10⁸ m³) are common along the upper Yellow River from Longyang Gorge to Liujia Gorge. The largest one on record reached 30×10⁸ m³, which had ever blocked and dammed the Yellow River. The study on the mechanism of giant landslides along the upper Yellow River would be important for construction engineering and countermeasures to prevent from any undesirable events. The author analyzed seven geological occurrences, and concluded that Dehenglong landslide and Suozi landslide occurred during 70-80 ka. They were triggered by an earthquake and dammed up the Yellow River at that time. They had a close relationship with the tectonic movement in Qinghai-Tibetan Plateau before ca. 80 ka, which is evidenced by the existence of the dammed lakes caused by Dehenglong-Suozi landslides.

Suoertou landslide, an old giant landslide in Zhouqu County in Gansu Province, has been moving slowly since 1970's.The geological environment indicates that the slow-movement was controlled by behavior of slide's materials under four factors, including weight of the slope, activity of its boundary faults, incision of Bailongjiang river at its toe, and the groundwater within the slope; although only the slope weight has been confirmed for its importance. Based on the field investigation and monitoring data analysis, numerical simulation was adopted to analyze the contribution of the other three factors to the activity rate of the slide. It was found that the creep behavior of Suoertou landslide was mainly controlled by the groundwater and active fault in addition to its rheological nature, in which the effect of rise of water table was great than active fault on the dynamics of the slide. The numerical simulation results showed that Suoertou landslide's dynamic modes were similar with different velocity under different controlling factors. It was also found that when boundary faults were activated, the velocity of Suoertou landslide increased by 20%-47% compared to the condition of only gravity was considered; the landslide's velocity increased with the increasing of water table, the velocity increased by 20%-97% with 1 m rise of the water table. However, the incision of Bailongjiang river had only an influence on the velocity of the front part of the slide, and the amplitude of its velocity had no obvious positive relationship with the flow rate of Bailongjiang river.

To improve the existing technology of rock breaking, this paper presents one method for calculating rock-breaking behavior under shock vibration of high frequency and micro amplitude. Firstly, a shock vibration model of high frequency and micro amplitude is established. On this basis, rock-breaking volume, rock crushing work ratio, and crack length are calculated. And then, the impact of frequency and amplitude on the rock-breaking efficiency are analyzed. The results show that the circle of impact time decreases to 0.001 s when the frequency increases to 2 000 Hz; while the impact force increases to 12 900 N, and the bit penetration and final impact velocity are also increased. High frequency and low amplitude can increase the rock-breaking volume, reduce the rock crushing work ratio, and increase the rock crack length. The reliability of the calculation method is verified through comparison of the calculation results with the experimental tests. The study results are useful to improve the rock-breaking technology, efficiency, as well as the tool development for rock breaking under shock vibration of high frequency and micro amplitude.

Analysis of flux recession process is an important method to calculate hydrogeological parameters of karst aquifers. Based on the theoretical method of flux recession analysis, the author took the flux records from Sep.25th to Oct. 13th, 2013 as samples out of the total 8 784 sets of flux data through monitoring the export of underground river per hour throughout the whole year to fit flux recession process by MATLAB; and then the attenuation coefficients of three phases were obtained as 0.642 5, 0.025 8 and 0.001 5 respectively; at last, the ratios of hydraulic conductivity to specific yield were calculated, and the hydrogeological parameters were confirmed by given cranny ratio which was roughly equal to the specific yield. The result shows that the hydraulic conductivity for karst conduit, fissured and bedrock medium in Zhaidi basin were 258.87 m²/d, 3 865.98 m²/d, and 40.64 m²/d respectively. With the requisite hydrogeological survey, defined conduit distribution, and runoff distance, the method of flux recession analysis could be used to calculate the conductive capability and specific yield of different media for a karst aquifer.

A systematical field investigation is carried out in the upper Yellow River valley from Jingtai to Jingyuan reach. Palaeoflood slackwater deposits (SWD) are identified at several sites. The Holocene sediment profile at the site of Jinpingcun (JPC) is chosen for a further study on the palaeoflood hydrology. OSL dating and stratigraphic correlation with Jixian (FJJ) site in the middle reach gorge of the Yellow River show that these extreme palaeoflood events occurred during 3 200-3 000 a B.P., at the time when the climate was at the turn from the Middle Holocene climatic optimum to the Late Holocene dry period. This corresponds to the transition period from Shang Dynasty to Western Zhou Dynasty when many serious drought and flood disasters, harvest failures, and major social changes occurred. The palaeoflood stage is obtained by palaeohydrological methods. The reconstructed palaeoflood peak discharges were 16 110-17 740 m³/s using the slope-area method. Reconstruction of current flood (in 2012.07.31) and comparison with the gauged discharge prove that the hydrological method and hydrological parameters used are reliable. These results are very important to establish the relationship between peak discharge and occurrence frequency by 10 000-year time-scale in Lanzhou to Jingyuan reach. The method is very useful in Hydraulic engineering along the upper Yellow River.

In order to develop the high photocatalytic performance of TiO₂ under visible light and make it easy to be separated from the treated liquid, a visible light response photocatalyst is prepared through doping of the upconversion luminescence agent Er³⁺:YAlO₃ with TiO₂, and immobilizing Er³⁺:YAlO₃/TiO₂ on the surface of Polyurethane Sponge (PS) by use of sol-gel method. Based on the surface response methodology (RSM), an experiment is designed to assess the individual and interaction effects of the three operating parameters (hydrothermal treatment temperature, TiO₂ concentration, and PS-to-TiO₂ sol ratio) on the efficiency of phenol removal. The corresponding optimum preparing conditions are 110-114 ℃, 60-65 mg/L, and 20 g/L. The measured efficiency of phenol removal is maximijed under these conditions.

The traditional fixed-wing airborne electromagnetic survey lost multi-component measurement information for the reason of using the total field as the data base for the conductivity depth imaging. The imaging precision is decreased due to the non-uniqueness of the dB/dt. A joint conductivity depth imaging approach based on the lookup method of two-component B field response is proposed. Based on the fixed-wing electromagnetic forward calculation, this paper establishes a table of B_x-B_z-conductivity-altitude, uses B field to avoid the uncertainty of conductivity due to the binary value of electromagnetic data, uses the joint lookup method of two-component B field and interpolation algorithm to determine the conductivity, and then takes the advantage of the diffusion depth formula to obtain the depth, and finally to process the joint conductivity depth imaging. Compared to the total field and simple component lookup method applied in the one-dimensional and quasi-two-dimensional forward simulation, the CDI of two-component B field gets more ideal fitting effects; and the imaging precision is improved by 7%.

Scalar CASMT is inadequate to the face of great depth and three-dimensional detection; while tensor CSAMT is becoming a research focus. On the basis of previous studies, two kinds of tensor CSAMT processing technologies are proposed; which are Mohr analysis and the traditional coordinate rotation. By innovative use of the integrated electrical instruments developed in China for the first time, we demonstrate the application of tensor CSAMT. The results show that through Mohr analysis and traditional coordinate rotation, the vertical and horizontal structure of underground geological bodies can be qualitatively analyzed; apparent resistivity and impedance phase in principal axis orientation correspond with the targets; and the comprehensive analysis of resistivity inversion and drilling information are profitable for the establishment of geological-geophysical models on the test area.

In a multi-wavelet decomposition and reconstruction of seismic signal, the matching pursuit algorithm can be adaptive according to the characteristics of the seismic signal itself. In view of the large amount of calculation, the author presents a particle swarm fast optimization algorithm, which is used for fast search optimum matching atoms of seismic signal sparse decomposition. In concrete, the searching area is determined by the energy concentrated part of Gaussian function in the process of iteration. This can avoid the greediness during the searching process, and effectively reduce the sparse decomposition complexity. At the same time, a polynomial mutation operator is introduced in the particle swarm optimization algorithm, which can effectively avoid the excessive concentration during searching the optimal solution. The experimental results show that the algorithm can reach a precision of matching pursuit decomposition 67 times higher than before, and increase the calculation efficiency by 153 times.

According to the operating principles of array lateral electrode arrays in horizontal wells and highly deviated wells, electric field is studied by using multiple electric field superposition method, and the 3D finite element method is employed to simulate electric field distribution of various points, and then electric field linear superposition principles are used to get the array lateral logging response. Based on the computer simulation, five array lateral logging curve radial investigation depths are obtained. The array lateral radial detection depth is smaller than the deep lateral detection depth. The effect of well deviation and variation of depth of invasion on log response in the 3D formation model is examined; and the characteristics of array lateral log response in horizontal wells and highly deviated wells is analyzed. The simulation results are as follows: well deviation has a small impact on array lateral log response when the well deviation is less than 15°, and correction of well deflection is not necessary; while the well deviation must be corrected when the horizontal well deviation is more than 60° in a highly deviated well due to a greater difference of array lateral log response between highly deviated wells and vertical wells.

During tunnel excavation, a variety of geological disasters might be encountered, such as faults, caves, et.al. Tunnel seismic prediction (TSP) is adopted to mitigate the possible damages. Although TSP technology is used widely, the research about TSP is currently focused on its engineering application cases. We use the finite element method to simulate the tunnel seismic wave field, employ wave field snapshots and time recording method on the impact of faults on the characteristics of the propagation of tunnel seismic wave field, and inversely process the time record of model containing the fault. The digital model of the velocity scattered image and the reflection interface position are obtained, and the fault position from velocity scattered image processed with the default values set by using TSPwin is agreed to the one from the model. In respect to the layered model for an abnormal velocity zone, P-wave is more precise. The system of TSP is strong for its feature of anti-noise. The numerical simulation is verified finally through the process and analysis of the engineering cases.

In order to discover the mechanism and anomaly origin of geoelectrochemical extraction, an experimental study has already been conducted in Dagenlong Tungsten deposit in Hunan. We take soil samples by interval of 20 m, and implement the geoelectrochemical extraction under the working conditions of the following three: the extracting time is 24 hours, the dose of HNO₃ is 1 000 mL, and the distance between two electrodes is 50 cm. The result shows that the variation of metal element content is insignificant in soil after extracting, and the extracted metal elements are proportional to the whole metal in the soil. The morphology comparison of anomaly between the geoelectrochemical extraction and the secondary halo shows that Ni and Co is clear, W is less, and Cr has no anomaly. The characteristics of anomaly mainly depend on the content proportion of element which is active in soil. Comprehensive analysis shows that the anomalies of geoelectrochemical extraction related to the relative position of the ore body. It is easy to form anomaly at downhill position, and distance too close to native ore body have obvious interference to anomaly. In this ore deposit area, the higher weathering degree, the better Co,Ni anomaly of geoelectrochemical extraction. The anomaly width of geoelectrochemical extraction is smaller than secondary halo.