Through 1∶50 000 highprecision aerogeophysical survey in ErenhotDong Ujimqin Banner area, the authors found lots of aerogeophysical anomalies, which included aeromagnetic, aeroelectromagnetic and aerogamma energy spectrum anomalies. These discoveries have special significance in the oreprospecting work. Combined with geological and geochemical data, the authors studied these aerogeophysical data, analyzed the metallogenic regularity of this area, and delineated the polymetallic prospective areas as well as most important prospecting targets. Some anomalies were inspected, and some field work was conducted so as to bring the anomaly potential into full play in oreprospecting. It is believed that the highprecision aerogeophysical data can play a vital guiding role in the prospecting for iron deposits and polymetallic deposits. The results obtained by the authors can accelerate the ore-prospecting work and make new breakthrough in this aspect.

The surface of the Ulan Dele molybdenum ore district is heavily covered, and the prospecting criteria are inconspicuous. The integrated geophysical and geochemical methods has hence played a vital role in the discovery and delineation of the molybdenum deposit. The summarization of the geophysical and geochemical prospecting criteria for this deposit is very important in search for the same kind of ore deposits in other places of the ore-forming prospect area.

The preliminary integrated geophysical and geochemical investigation of polymetallic resources led to the discovery of the Zhitianchong silver ore spot in Huaining County, Anhui Province, which is a silver ore spot discovered for the first time in the Huaining metallogenic area. The mineralized body of this silver ore spot occurs in the middle part of Silurian Gaojiabian Formation and shows stratabound features, belonging to a new species and new horizon. The discovery of the Zhitianchong silver ore spot sheds light on the oreprospecting work in this area. This paper has described mineralization conditions of this silver ore spot and characteristics of composite geophysical and geochemical anomaly and oreprospecting effect, and summarized the exploration model formulated at the stage of preliminary ore resource survey.

Iron ore deposit of the altun mountainliweiqiming is a hidden deposit，which was covered by a set of precambriancambrian boundary deep metamorphic rock.Through the surface highaccuracy magnetic survey，we obtained magnetic anomaly data and outlined the scope of the magnetic anomaly.Based on the analysis of reduction to the pole and upward continuation，the distribution and spatial signature of the hidden iron ore deposit were determined，Which presented specific basis of physical geography for the development of iron ore deposit.

This paper has dealt with the aeromagnetic data in the Bsishan Mountain of Weining, studied the characteristics of magnetic and gravity anomalies and explained buried rocks in the study area and analyzed the relationship of polymetallic deposits and mineralizations to magnetic anomalies in the Beishan Mountain of Weining. With the data of electromagnetic sounding, the deep ore-forming prospect area is predicted.

The mechanism of hydrocarbon vertical micropercolation in oil and gas accumulation has been a point at issue in the basic theoretical study of oil and gas geochemical exploration. There exists much controversy concerning the genetic mechanism of the nearsurface oil and gas geochemical anomalies. Based on the measurement of waterpercolating artificial core rate by the selfdesigned modeling experiment device under the condition of normal temperature and high pressure together with digital simulation results available as well as case studies of hydrochemical exploration, the authors hold that it is impossible to form oil and gas micropercolating anomalies via vertical migrating through deep compaction water of the basin and meteoric water and penetrating oil and gas accumulation unless there exist ideal channels such as large fissures and faults at the depth. This is to say that the mechanism of migration with water is not the major genetic mechanism of the oil and gas anomalies. The results obtained by the authors provide experimental evidence for the study of the genetic mechanism of oil and gas anomalies.

The alterations related to gold minerlization in the Luerba gold deposit are silicification, pyritization and carbonatization, which find expression in the existence of limonite, jarosite and kaolin at surface. Litho-geochemistry of the ore deposit indicates that Au and As are closely related to each other,  Sb, Hg, Au and As constitute near-ore or distal indicators of Au, and Au, As and Zn stably exist in such minerals as pyrite or arsenopyrite. These relationships are inherited in soil but disintegrated in stream sediments. Therefore, Au and As can be selected as indicator elements in litho-geochemical survey and soil geochemical survey, whereas Au, As, and Sb should be taken into account together in stream sediment survey. The dilution or concentration of Au in surface materials only markedly manifest itself in the mining area, and basically takes place at the step of migration from soil to stream sediments. The mechanical mixing and sorting of the stream and the sieving during sample preparation are decisive factors responsible for the reasonable decrease of gold content. In the secondary material of the background area, there is no remarkable dilution or concentration of gold.

 Using the Continuous Electromagnetic Profiling method (CEMP)，the author performed a survey in Longwei lake area of northern Qiangtang basin within Qinghai-Tibet plateau. This paper deals with the technique of data collection and data processing, gives the result of CEMP section and its interpretation. A comparison with the results obtained by such means as 2D reflection seismic survey, magnetotelluric sounding and verification of No. Qiang-Zi 1 borehole shows that the result of CEMP is effective and the method can be used in the investigation of shallow geological structures.

Aero-electromagnetic data applied to geological mapping are very important in aero-electromagnetic exploration. These data can not only provide abundant new information of regional geological structure but also improve the exploration effect and raise the recognition capability of anomalies for surveyed objects. At present, the aero-electromagnetic method in China uses three kinds of T-R loop sets. On the basis of their principles, this paper has discussed specialities of the aero-electromagnetic induction secondary field response parameters and their conversion parameters called "mapping interpretation parameters", and pointed out the existing problems in the aero-electromagnetic survey. The mapping technique for lithologic-geological unit was used in Longmen and Wuda areas, with fairly good results obtained.

Based on the sequence stratigraphy theory, this paper subdivided the Yingcheng Formation into four sedimentary sequences and one volcanic intercalation by means of sequence stratigraphic classification and comparison. According to the analysis of coring data, logging data, palaeontological characteristics, rock slices and grain sizes, the sedimentary facies in Yingcheng Formation should include fan-delta subfacies and lakes subfacies. On plane, the authors used seismic inversion tools to predict the distribution of sand and employed seismic waveform classification technology to do seismic face analysis. With the division results of the microfacies in individual wells, a comprehensive forecast was made for sedimentary facies distribution in Yingcheng Formation, and the evolution regularity on plane was analyzed. During the deposition of the Yingcheng Formation, there was a complete sequence development process in Dongling area. The sedimentary facies assumes an overall EW-striking spreading, with obvious variations  in the NE direction. Material source from the northeast was adequate, and the sedimentary facies on the whole formed an integral sequence sedimentary sequence, reflecting the sedimentary characteristics of the lacustrine plane from expansion to shrinkage.

The clastic reservoir of Carboniferous Karashayi Formation has become important substitution to the Ordovician carbonate reservoir in the Tahe Oilfield. The Karashayi sand and mud thin interbedded reservoir is heterogeneous and laterally variable. On the basis of analyzing the features of the curves, the authors built a lithologic index curve based on the integrated gamma ray curve and neutron porosity curve. The characteristic curve was used to invert the reservoir. A comparison with the ordinary acoustic impedance inversion shows that the characteristic curve can improve the inversion effect remarkably and recognize the thin interbedded reservoir efficiently. The new method was used to identify thin beds in the Tahe Oilfield, with satisfactory results obtained. This method has provided a new simple and effective means for the study of Carboniferous clastic reservoirs in the Tahe Oilfield.

A certain basin in northeast Guangdong is dominated by uranium mineralization together with certain amounts of such metals as Au,Ag and Mo.Through 1∶50 000 stream sediment survey performed in this basin,some first grade and quite a few second grade polymetallic anomalies of such elements as Au,Mo,Sb,Mn and Pb were discovered.The good results obtained in this survey have provided a reliable geochemical basis for further geological and oreprospecting work and the entire exploration work in this basin.

Geochemical anomalies in desert are controlled by certain geological structures, and different distribution features of radioactive elements (or anomalies) reflect characteristics of different rocks, strata, volcanic activities and fault actions. Fundamental geological researches on the basis of data obtained from 1∶200 000 regional geochemical survey are of great guiding significance in geological oreprospecting work.

The Extremely Low Frequency (ELF) method is a new artificial source electromagnetic detecting technique, which should be improved through forward modeling and data checking for the processing of the measured geophysical data. In this paper, the theory of the ELF method is systematically analyzed. First, in accordance with the studied objects and the problems, the geological structure model and its corresponding mathematical model are built. Then, on the basis of the electromagnetic theory and the selection of a suitable calculation method, the time-harmonic horizontal finitely long grounded wire is set on the crust surface, the mutual coupling of the ionosphere, the air layer and the layered earth are considered, and the general expressions for frequency-domain electromagnetic responses are deduced. These expressions connect electromagnetic response with all parameters such as the conductivity of the ionosphere, and provide theoretical foundation for forward modeling and the feasibility of the ELF method for resource exploration. The modeling indicates that the shape of the electromagnetic response curve is variable, and the electromagnetic waves are reflected back and forth between the ground and the ionosphere due to the existence of the ionosphere.

The residual anomaly component factor score method which uses the means of trend surface to process geochemical data was adopted in the working area to extract the residual anomaly components that indicate local anomaly changes. R-factor analysis was carried out for residual anomaly components and, as a result, 3 factors closely associated with the mineralization were obtained. Score diagrams were drawn to reflect the distribution of geochemical anomalies in the study area and provide the basis for the optimization of prospecting targets.

Pseudo-random signal has been widely used in seismic exploration because of its excellent auto-correlation. This paper has deeply studied the important parameters related to the auto-correlation function of pseudo-random signal with the purpose of improving auto-correlation function properties of the pseudorandom signal. An analysis of the simulation results has revealed the relationship of the carrier frequency and primitive polynomial order to the autocorrelation function. The length of the pseudorandom scanning signal and the principle for the choice of the amplitude are also given in this paper.

Under the actual marine environment, the underwater ultrasonic measurement system has a certain limitation because of mechanical noises such as background noise and reverberation noise. The bispectrum time delay estimation method with Gaussian noise has shielding capacity and is capable of suppressing noise. This method adopts an accurate estimation of the signal time delay, and its power spectral bispectrum reconstruction is superior to the direct use of FFT transform power spectrum estimation, thus having relatively high precision and performance. In view of underwater ultrasonic detection deficiencies, the bispectrum estimation method is adopted due to its insensitivity to background noise. According to measured data obtained in laboratory pool, the applicability of the method is verified. The results show that the bispectrum method has better applicability than the cross-correlation method under the conditions of less prior knowledge and strong background noise.

The improvement of the surface seismic resolution is the aim of every geophysicist. This paper presents a new method by combining surface seism with crosswell seism. First, the matching operators are computed between the crosswell and the surface seismic data. Then, according to their correlation and distance, the 3D spatial operators are obtained. Third, the operators are applied to surface seismic data, and the 3D matched data are established. After that, a constrained model is set up by signal spiking. Finally, the broadband-constrained inversion is employed to complete the processing. Tests on synthetic data and field data show that this technology can improve vertical resolution of surface seismic data.

In many kinds of underground engineering，the determination of the attitude of the rock structural plane is a necessary step. This paper has analyzed and summarized three types of methods, i.e., core orientation method, drilling method and geophysical logging method or well-television method as well as their main features. The solid geometric method for determining the attitude of the rock structural plane is put forward based on measuring the imaging values and well deviation parameters. Computer programming calculation is realized. Theory and experiments show that the calculation principle of the method is correct, simple and accurate.

Compared with CHFR, which is widely used at present, Russian through casing resistivity logging technology has many advantages, such as not requiring well cleanout, great detection depth and higher practicability.  This paper analyzed the logging theory and technical characteristics of Russian through casing resistivity tool, and summed up the data application of nearly fifty wells which had successfully acquired materials. Fairly satisfactory application results were obtained in such aspects as the determination of the situation of the virgin formation oiliness, the monitoring of the dynamics of water injection, the checking of the movement of the edge and bottom water,  the search for the potential formation in the old wells, and the study of the potentiality and the distribution of remaining oil. These results provide reliable references for deploying new wells and regulating blocks. It is thus thought that Russian through casing resistivity logging technology can be widely applied to the remaining oil evaluation in old wells and blocks.

MapGIS was used to perform data extraction in such key areas of Peru as Acari, Huarato, Hierro Acari and Pampa de pongo. Various kinds of aeromagnetic data-processing were performed for aeromagnetic anomalies, and characteristics of the magnetic field before and after the processing were compared with each other. In combination with geological data, the distribution of the structures and ore deposits in the key ore districts was explained. Test and verification show that the practically exploited key ore districts are coincident with the conclusions reached by inverse analysis, thus proving the accuracy and effectiveness of the aeromagnetic method.

The complex resistivity dispersion experiment on soils with different water and chromic salt proportions constitutes the basis of the complex resistivity detection method used to evaluate the field polluted by chromium residue. Based on experiments on the soil complex resistivity dispersion properties under various kinds of conditions, the authors have found that the complex resistivity amplitude, phase, in-phase resistivity and out-phase resistivity can be influenced by the water content and contamination content, but the complex phase and out-phase resistivity and the phase angle have obvious dispersion properties. The experiment results show that the complex resistivity detection technology based on soil dispersion properties can be used to evaluate the field polluted by chromium residue rapidly and effectively.

γ-ray spectrometry was used to explore the known area of the Liangzhu ancient ruins and, as a result, the response characteristics of the radiogenic anomaly with both high concentration of radioactive elements and high total count rate on the gabarit was obtained. The anomaly width is coincided with that of the gabarit, the anomaly axis is the central location of the gabarit, and the axial strike is the same as that of the gabarit. On such a basis, γ-ray spectrometry was carried out in the unknown area. By comparison with anomaly characteristics of the known area, the location and the width of the gabarit in the unknown area were deduced. The result obtained will surely provide some useful reference for identifying the existing gabarit and its distribution.

Environmental geological survey in a certain high incidence area of esophageal cancer shows that soil parent materials of this area are more viscous and heavy and have higher organic matter than the soil parent materials in lowincidence areas, and nitrite, N-NH3 and N-NO3-in drinking water wells of this area are seriously higher than their standards. The mortality of esophageal cancer is as high as 269/100 000, by far higher than the national standardized mortality of 10.02/100 000. Studies show that soil viscocity and heaviness cause slower water flow and higher nitrite content in the well, which seems to be the main cause for high incidence of esophageal cancer in the study area.

Based on the analysis and comparison of Chinese date and soil samples collected in the central part of the Taihang Mountains, this paper deals with the factors affecting the quality of highgrade Chinese dates in Taihang Mountain area, and points out the primary and secondary relationships of various factors affecting the growth of Chinese dates, such as structure, rock, soil, geochemical anomaly, climate, underground water and landform. Geological structures control the distribution of gneiss, which, in turn, is related to the growth of high-quality Chinese dates; areas with elevation lower than 500 m are suitable for the growth of high-grade Chinese dates, and the quality of Chinese dates is even better in areas characterized by elevation of lower than 200 m and distribution of gneisses, gullies, valleys and sunny slopes.

With the continuous seismic event and good lateral resolution, the precision of seismic interpretation can be improved. Seismic image shows seismic event with textural features. According to the image textural features, the edge orientated enhancement diffusion is applied to seismic image enhancement and, as a result, the processed image texture (seismic event) has better lateral resolution. The edge orientated enhancement diffusion is based on the nonlinear diffusion, which uses edge detection and diffusion of image enhancement techniques. This method chooses diffusion tensor and eigenvalue according to the information of edge position and direction. Smoothing along the edge is in the edge region, and diffusion along the edge and in the vertical direction of the edge is in the smooth region. Theoretical analysis and numerical calculations show that the edge orientated enhancement diffusion allows noise removal and structure closure at certain scales, with the preservation of both orientation and magnitude of discontinuities. This image enhancement technique is likely to improve the accuracy of seismic interpretation by high event continuity and good lateral resolution of the event.

For the purpose of exploring uranium deposits in Pingxiashui area of Nanxiong City, Guangdong Province，the authors applied the fractal data-processing method to determining the anomaly lower limit of the radioactive exploration data. Then the results obtained by this method were compared with those obtained by the conventional data processing method of "average value plus three times of variance". The results show that the fractal method can be applied to the processing and interpretation of radioactive exploration data, with its effect better than that of the conventional method. The metallogenic prognosis based on data-processing of fractal theory would provide the basis for further prospecting.

In order to improve the efficiency of the inversion of CSAMT sounding data, this paper suggests that parallel computation should be introduced into the 1-D iterative inversion of CSAMT sounding data for pseudo-2D inversion interpretation. Based on multiprocessor and multi-core workstation and using the programming technology of multithread and multi-process, the authors formed the parallel algorithm and the final program. The parallel algorithm was adopted for inversion interpretation of measured data, and the result shows that the pseudo-2D inversion using parallel algorithm can greatly improve the efficiency of the inversion of CSAMT sounding data.

Nested variance has been widely used in evaluating the quality of geological data. In fact, its computing process is complex, especially in the work with many samples such as the  geochemical exploration and the manufacturing of the standard sample. As no software now can compute nested variance directly, people usually use the counter to count it or compute the F value in Excel so as to get the critical value through checking the table. Aimed at solving this problem, this paper has compiled the program in VBA language in Excel with the purpose of realizing the computation of threeclass nested variance convincingly. At the same time, this paper discusses the utilization of the t-test in twin-swatch which collects samples two times but tests every sample only once.

This paper deals with the basic principles of elastic wave tomography testing techniques for the old bridge pile. With practical examples of testing on the model pile, this paper demonstrates the effectiveness and accuracy of this method.

Exemplified by the typical radar profile measured in the karst area of Guangxi, this paper deals with the practical result obtained by the application of the ground-penetrating radar to the detection of the properties and spatial shapes of the tunnel karst and points out the construction environment and lateral influence problems that deserve attention in practical application.