Sedimentary exhalative deposits (SEDEX) widely distributed in the world constitute an important type of ore deposits. They are major sources of Zn and Pb and possess more than 50% and 60% of world Zn and Pb reserves, respectively. In this paper, based on consulting various research achievements and vast literatures concerning this type of ore deposits, the authors provide an overview of several aspects of the sedimentary exhalative deposits, such as their tectonic settings, geological and geochemical characteristics, oreforming model, progress of exploration, and prospecting characteristics, and point out several directions in the further study of  SEDEX deposits.

Owing to interferences of several factors, the deep seismic data obtained from northeastern South China Sea basin are poor in quality, low in signaltonoise ratio and weak in effective wave energy. In addition, the characteristics of reflection waves of the mediumdeep layer are not clear. In view of such a situation, the method of comprehensive interpretation that applies gravimetric and magnetic data in combination with seismic data is adopted in this paper. By analyzing the features of peripheral rocks in the study area and further processing and analyzing the gravimetric and magnetic data in combination with the stratigraphic analysis, the authors found the distribution of Mesozoic strata, thus providing a scientific basis for oil and gas exploration.

 The Transient Electromagnetic Method (TEM) was used to detect geological information of concealed sandstone type uranium deposits in Mahuangquan area. TEM surveying data were processed to divide structural units of the basin base; stratigraphic formation and sedimentary environment were analyzed, and faulted structure was interpreted. Subsequent drilling result shows a good application effect, and hence this method can provide effective geological data for sandstone type uranium deposits in the basin. It is held that the interpreted slope area and alluvial fan can be regarded as the key places for further oreprospecting work.

Aeromagnetic survey using helicopter with a fixed receiver is suitable for ore prospecting in local key areas, because the survey method has a low flying height of 100 m, a small sampling interval of about 3 m, a high locating precision of less than 1 m, and a low cost of about 30% of the expense of ground magnetic survey. In this paper, the orecaused anomaly was determined by a comparative analysis of the ore body thickness and the aeromagnetic anomaly and a mutual verification of the forward and inversion calculations. The borehole site was determined by precise inversion of the aeromagnetic anomaly. The effectiveness of the method is verified by the fact that iron ore bodies were discovered in all the three borehole sites deployed by the authors at the depth of the Daye iron mine.

 Kaifeng depression, located in the southeast corner of the JiyuanKaifeng depression, is enriched with deepseated groundwater sources. The rich geothermal water rock (thermal reservoir) commonly has lower resistivity than the insitu rock, and the reduction degree of its resistivity is related to the extent of water content, water temperature and mineralization. Based on geoelectrical anomaly, the authors inferred the distribution of the thermal reservoirs. A study of the magnetotelluric sounding method (MT) shows that the resistivity values of the basement are lowest in most surveying points north of F1 fault, implying the existence of the relationship with the geothermal water in the strata. According to the distribution of geoelectrical anomalies in the survey area, the authors locate the relatively enriched area of geothermal water in the basement of this area, thus providing an important basis for further geothermal exploration.

IP sounding anomalies can effectively reflect metallic sulfide mineralized ores and altered rocks in the Quellaveco copper deposit. The size of chargeability is related to the metallic sulfide amount of rocks, and the high or low resistivity is caused by the alteration intensity of rocks. Intense anomalous chargeability occurs in strong pyritized rocks. Intermediate anomalous chargeability is caused by copper and molybdenum (mineralized) ores. Low or intermediate resistivity anomalies occur in strongly or slightly altered rocks. Nonmineralized and nonaltered rocks show high resistivity and low or no chargeability. The inferred map of inversion results has a great significance for drilling deployment.

 Carbonnaceous bed is one of the major interfering factors in geophysical exploration, especially in electrical exploration. Aimed at finding an effective method to distinguish carbon anomalies from orecaused anomalies, the authors employed such integrated geophysical exploration methods as highaccuracy ground magnetic survey, timedomain induced polarization method (TDIP) and controlled source audiofrequency magnetotellurics (CSAMT) in search for ore deposits in Beishan area, Gansu Province, and attained remarkable achievements. The technique was successfully used to upgrade a leadzinc ore spot to a potential mediumsize polymetallic deposit. An integrated application of several geophysical methods can avoid such disadvantages in utilizing only one method as limitation and interpretation ambiguity. Such an integration has full advantages of all the geophysical methods, and can effectively distinguish orecaused anomalies from hidden anomalies related to carbonaceous covering bed. The results obtained by the authors are of great guiding significance for oreprospecting work in Beishan area of Gansu Province.

 Based on electrical parameter measurements of rocks and ores, the authors analyzed the apparent resistivity and apparent chargeability characteristics, and the results provided some good basic physical conditions for the application of the induced polarization method in this area. Hence the middle gradient induced polarization and symmetrical quadrupole method induced polarization were employed for the known No. 201 ore body in the mining area, and the measured anomaly distribution was basically coincident with the distribution of molybdenum ore bodies. This result was verified by drilling.

Based on an integrated study of 90 airborne geophysical anomalies in a certain area of Mongolia, the authors inferred that quite a few of them are caused by skarn magnetite deposits. Surface anomaly inspection and engineering verification reveal that five of these anomalies are related to magnetite deposits. A preliminary estimation shows that ore reserves in the five anomaly districts can reach a hundred million tons or so.

During the exploration of the Huangzhuyuan gold deposit, the authors established the geophysical and

geochemical model for anomaly appraisal on the basis of geological, geophysical and geochemical characteristics of the

ore district. With this model, the properties of the anomalies were clarified, the denudation degree of the ore body was

preliminarily discerned, and the attitude of the ore body was determined through IP profile survey. All this shows that

the ore-prospecting effect is fairly satisfactory.

On the basis of detailed geological work, the authors conducted 1∶5 000 largescale oreprospecting work in the newlydiscovered orebearing horizon of Qiongzhusi Formation within the Huize PbZn metallogenic belt on the west margin of the Yangtze platform by means of soil geochemical survey and geophysical exploration. Oreprospecting engineering inspection in the soil geochemical anomaly concentration district of the study area reveals that the anomaly concentration center is consistent fairly well with the newlydiscovered ore body, suggesting that soil geochemical survey is quite effective in the study area and deserves further popularization.

Soil geochemical survey was conducted in the Aifa ore district, Chile. It is shown that the application of this method can further point out the prospecting direction, delineate the target, reduce the oreprospecting area, and accelerate the oreprospecting work. Soil geochemical survey has played an important role in geological oreprospecting work there and yielded satisfactory application result.

 This paper deals with a new algorithm and the concept and characteristics of the ant colony algorithm. The authors applied the ant colony algorithm to Rayleighwave inversion so as to deduce underground structure from dispersion data, analyzed the problems worthy of attention in the use of the ant colony algorithm and employed the distributive curve of pheromone density to change and narrow the further search scope with the purpose of raising the inversion speed. The inversion analysis of the theoretical model and measured data shows that the ant colony algorithm is effective.

Based on statistical characteristics of energy spectrum and spectrumshifting features in spectrometry, the

authors applied the dual model of Hidden Markov Models to the simulation of spectrumshifting. Transient

characteristics of energy spectrum were described and then transformed into a parametric model by Gaussian Mixture Mode.

The conditions of spectrumshifting in the measurement of energy spectrum were simulated by state transition of Hidden

Markov Models, and then the parameters of Gaussian mixture model were adjusted. Practical application shows that these

parameters can be adjusted flexibly by this method to meet the various requirements in simulation of energy spectrum

shifting, and hence this method is a parametric simulation method with good performance.

Largescale and highprecision aerogeophysical survey provides reliable data for lithologic classification, and BP neutral net supplies effective means to lithologic classification. Based on the principle of BP neutral net model, the authors compiled the BP neutral net software for the processing and interpretation of aerogeophysical data and successfully used this software to the lithologic classification and interpretation of airborne gammaray spectra. Practical examples show that the application of the BP neutral net method to the processing and interpretation of such aerogeophysical data classification problems as lithologic division has very obvious effects.

 This paper describes the forward computing method of phaseIP (induced polarization) electromagnetic coupling, which is based on the uniform terrestrial condition. The intermediategradient and dipoledipole device electromagnetic coupling responses are simulated. According to the rule that electromagnetic coupling varies with the working frequency, this paper puts forward an electromagnetic coupling correction means that adopts phases of two frequencies. The effectiveness and the applying effects of the decoupling method are analyzed in combination with practical examples.

 It is difficult to exactly detect small objects in complex shallow subsurface. As the energy of backscattered signal from the target is low, backscattered signals from target and ground surface are overlapped. In addition, clutters created by ground surface and movement strongly depress the signaltoclutter ratio when shallowly buried small objects are detected by portable ground penetrating radar (GPR). An algorithm for detection of shallowly buried objects based on principal component analysis (PCA) is thus proposed in this paper. Via PCA decomposition, current Ascan data are projected onto the projecting direction of background data. A set test function is compared with adaptive threshold to decide if current Ascan data are from an object. Detection of shallowly buried small objects can be achieved in combination with background data dynamic updating. The data tested in sand, laterite, clay and lawn were processed, and the results show that shallowly buried objects can be detected using algorithm based on PCA.

The prospecting condition test on the portable XRF analyzer of IED2000P was conducted in the Jingzhou silverpolymetallic mining area of Jixi, Anhui Province. Based on a comparative study of different densities of survey points, rocks and soils, different humidity conditions, and measurements of rock and its powder, the authors determined the best application conditions. The size of anomaly and real workload should be considered when the density of survey points is to be chosen. The XRF measurement of rock is better than that of soil in that the former reflects the anomaly characteristics of a geological body more objectively. The humidity factor can reduce anomaly intensity but cannot eliminate an anomaly. The XRF measurement of rock powder is better than that of rock. The comparative study and correlation analysis between the XRF measurement and the sample analysis of geochemical primary halo show that the prospecting method with the XRF analyzer is a convenient, fast and effective prospecting method.

A statistic analysis was made for samples of active state elements determined by ICPMS from July to

Decembers. Precisions of the 6step sequence extraction method for Cr, Cu, Zn, Cd and Pb were as follows:

waterextractable metals, 5.4%~60.1%; ionexchangeable metals, 10.8%~62.9%; carbonate bound metals, 8.0%~26.6%;

organically bound metals, 6.6%~27.3%; occluded metals in iron and manganese oxides, 5.3%~13.6%; and strongorganically

bound metals, 8.5%~33.5%. The detection limit and signaltonoise ratio of the method were also investigated. The

results show that the determinations of occluded metals in iron and manganese oxides are stable and credible, but the

stability and sensitivity of waterextractable metals and ionexchangeable metals need to be improved.

This paper describes the hardware and software of the probe, the core component of the new generation Xray fluorescence logging instrument. SiPIN semiconductor detector has been adopted in XRF logging probe and a structure fixing the excitation source on both sides of the detector has been designed. In this system, the ARM7 microprocessor is used as a control core, and RS485 is employed as communication protocol, with the maximum measurable depth being 2 000 meters below the ground. This system was tentatively applied in the Lala copper mine of Huili County, Sichuan Province, and the results show that the Xray fluorescence logging instrument can obtain the content of elements in various ores within rocks and sidewalls rapidly. Hence this system provides an effective analytical method for exploring deeper resources.

Based on results of multipurpose geochemical survey performed in southern Songnen plain and a study of the variation of element content in soil and correlation of elements, this paper, with the Zhalong wetlands as the studied object, probed into the geochemical regularity governing the distribution of soil elements in the wetlands. According to the influence of the environmental change of the wetlands on the soil element content and the calculation of soil organic carbon reserves in surface soil, this paper analyzed the ecological environmental action of the wetlands from the angle of geochemistry.

On the basis of the electric, radioactive and magnetic differences of soil, rock and water body and through investigating physical character variations of these three bodies, the authors conducted structural mapping and studied and evaluated water resource environment. It is concluded that three major factors have affected the water environment of coastal areas, i.e., the influence of marine transgression caused by geological movement, the surface subsidence resulting from the falling of the underground water level caused by human activities, and the water quality pollution and living environmental pollution from the natural and humancaused nuclear radiation.

 Based on the introduction of Zoeppritz equation and Approximate equations,we set different parameters to draw the differences between the Zoeppritz equation and Approximate equations when density, P wave velocity and Poisson ratio is different.We also analysis the curves and summed up the effect of those differences.

On the physical background of solid annealing process's properties, Simulated Annealing Algorithm is one sort of global optimization algorithm. This algorithm could solve the nonlinear problem and "Cycle Skipping" phenomenon of residual correction, but the disadvantages of redundant iteration and slow convergence speed also exist. Aiming at the above disadvantages, this paper proposed the following improved program: In the process of iteration, in order to decrease iterations and increase the convergence speed, the improved algorithm adopts new program to control the attenuation of temperature; The improved algorithm adopts new target function to increase the processing speed. By limiting the model disturbance in the condition of low temperature, the improved algorithm could obtain the optimal solution more quick. By processing the simulation data and actual seismic data of Algeria, the improved could decrease iteration times and improve convergence speed and efficiency effectively and enhance the continuity of reflection event, improve stacked sections' resolution and SNR (Signal to Noise Ratio).

 To tackle power interference in seismic record, the authors use S transform which can provide each frequency with the instantaneous amplitude and instantaneous phase so as to obtain the power interference amplitude and phase by using S transform in the timefrequency domain and get the power interference. In this way, the power interference can be reduced. Synthetic seismogram and actual seismic data processing show that this method can achieve good results, no matter whether the interference is a fixed amplitude and phase of power interference or a timevarying amplitude and phase of power interference.

Cross well seismic technology is a high-resolution geophysical method with random noise. In this paper, the improved

Empirical Mode Decomposition (EMD) method in the FX domain is employed for noise attenuation. Signals are decomposed

into a series of intrinsic mode functions (IMFs) after being transformed into the FX domain and then filtered by the

soft threshold function for noise attenuation. The processing of the emulated data and practical data with the improved

EMD method in the FX domain shows a great advantage in noise attenuation for the cross well seismic data and thus can

achieve a good result in improving the SNR of the seismic data. In addition, the method does not depend on the basic

function.

Because of its intuition and convenience, visualization technology is generally applied in geophysics. However, there exist certain limitations in inversing surface or borehole magnetic data alone, which may easily cause multiplicity. In this paper, the authors demonstrated the principle and crucial technology of 3D manmachine interactive inversion of surface and borehole magnetic data, and applied it to the Daye iron mine. This method not only has the full advantage of the surface and borehole magnetic data but also possesses the experience gained by interpretation workers. At the same time, it overcomes the disadvantages of inversing either of them alone and can get favorable result in mineral exploration.

 Deconvolution is a common method for improving the resolution of seismic image in surface seismic processing. The key to deconvolution is to calculate the operator of deconvolution. Seismic data are affected by the resolution and signaltonoise ratio in themselves. It is thus difficult to get the accurate operator of deconvolution. In this paper, VSP data were used to extract the wavelet because of its high resolution and high signaltonoise ratio. Then the accurate operator of deconvolution was obtained by adopting matching calculation between surface wavelet and VSP wavelet. At last, deconvolution of wavelet replacement was applied to post-stack surface seismic data. Practical processing results show that this method can enhance the resolution of surface seismic profile. In addition,, continuity of the event, characteristics of the wave group and overall quality can also be improved obviously.

The results of the gravity exploration work are evidently affected by the elevations of the gravitational observation points. In this paper, the GPS height transformation method is proposed on the basis of the accuracy of the EGM2008 model. The feasibility of the transformation method by using leveling data of an area is verified, and it is thus thought that this method is fully applicable to gravity exploration of medium and small scales.

 In order to apply MASW more extensively in engineering work, improve the quality of data acquisition, and increase the reliability of data, the authors studied some field data acquisition parameters such as trace numbers, channel spacing, offset and different sources on the basis of field test. Based on processing, analyzing and contrasting the testing data, this paper puts forward the appropriate parameter settings of MASW field data acquisition in engineering application.