The Zhunsujihua porphyry molybdenum deposit of Inner Mongolia is a medium sized metal deposits.Currently there is no deep drill hole data within the exploration area.In this study, high-precision seismic reflection measurement was conducted for detecting the deep metal deposits, ore-controlling structure and deep geological structure in the molybdenum ore district and its periphery.The reflection seismic method of 2 sets of high power vibrator for stimulation, 5 m group interval, 960 receiving and 80 folds were used, and high-precision seismic reflection profiles which can reflect clearly deep geological structure was obtained.Ore-passage structure and ore-controlling structure, concealed rock mass distribution as well as cross-cutting relationships of rock masses of Variscan and Yanshan period can be clearly explained on the section.The deep crustal fluid migration paths and dynamic process are discussed.The prospecting target zone is delineated in search for concealed metal ore deposits in the area.

In this paper, a comparative analysis of content-frequency fractal method was conducted for multi-range, multi-scale and multi-media geochemical field in the Dabaoshan orefield, It is proposed that the ore-forming elements with different dimensions and media basically show the same complex multifractal features, which is the necessary condition for elements to form the large-scale mineral deposit, but not a sufficient condition. The authors hold that the proportion of local anomaly number of samples accounting for all of the samples of ore-forming elements will be exclusively more than 2% reflected in the multi medium-scale data, the proportion is represented by the turning point of the value of continuous multi fractal dimension decrease, but the proportion of the value of elements without causing mineralization may be by far less than 1%. Fitting accuracy significantly influences the understanding of the type and properties of the content-frequency fractal curve.

With the train of thought ‘from the test and study along the known profile through the establishment of prospecting model to the prospecting prognosis in unknown area’, the authors conducted the prospecting application study of the geo-electrochemical integrated technology. The results obtained have proved the feasibility of applying the geo-electrochemical integrated technology to the prospecting for similar concealed lead-zinc deposits in this area. Combined with ore-forming geological setting, the authors established geo-electrochemical prospecting model. With this model, one Grade I prognostic target area, two Grade Ⅱ prognostic target areas and one Grade Ⅲ prognostic target area were delineated in the study area.

The Shuihekou gold deposit in Funing of Yunnan Province is a part of the Southeast Yunnan micro-fine-disseminated gold metallogenic belt. Soil geochemistry is a simple and effective method in search for micro-fine-disseminated gold deposits. Based on the 1:10000 soil geochemical survey in the study area, the authors analyzed the content and distribution characteristics of the four elements of Au, Hg, Sb, As and delineated the anomaly. The anomaly was evaluated in combiantion with the geological features of layer, structure, lithology and the prospecting indicators of Southeast Yunnan micro-fine-disseminated gold metallogenic belt, thus delineating six prospecting target areas. An orebody was found through engineering verification of No. 3 prospecting target, which provides effective evidence for prospecting potential of the other areas in The Shuihekou gold deposit.

Halahu is located in the Tibetan Plateau.The results of geological survey, AMT (Audio Magnetotelluric Sounding) and geochemical survey show that there is good perspective of natural gas hydrate prospecting in this area.High-precision seismic reflection experiments were carried out in search for natural gas hydrate in the area.1 200 receiving channels, 2 m group spacing, 1 m offset, 8 m shot spacing, 150 folds, the surveillance system excited in spread middle were used in reflection seismic survey.60 Hz geophone string (with 6 geophones) was adopted, each received channel receiving seismic wave in the form of point array.Excitation source was large vehicle-borne Vibroseis.Instrument recording factors used included 0.5 ms sampling, 2 s recording length and whole-band receiving.The high S/N ratio and resolution as well as obvious structural form characteristics were provided with seismic section obtained by the method.Validate hole location was determined according to land feature and the permafrost thickness, fault structure and high-speed distribution reflected on seismic profile as well as other data.

Gas chimney is a special geological phenomenon which is closely related to oil and gas generation and migration.The gas chimney recognition research on the seismic data contributes to the fault sealing, hydrocarbon migration and accumulation mode research.The gas chimney identification technology based on steering cube uses the dip and azimuth information for the identification of gas chimney.Combined with a supervised neural network analysis method, the technology extracts the seismic attribute combination which can reflect the prominent gas chimney seismic anomaly body.Compared with the previous method, this method has the advantages of high accuracy and efficiency.This method was applied to the Bohai A oilfield, and the research on the field hydrocarbon migration and accumulation mode was preferably completed, which laid the foundation for the growth of oil reserves. In addition, the authors conducted the risk analysis of the closed fault in the Bohai A oilfield, thus ensuring the drilling safety.

The Yantianqiao copper polymetallic deposit is located in the Chaenshi lead-zinc polymetallic ore concentration area on the northern margin of Hengyang basin. Ore-forming geological conditions of this area are very good. Copper polymetallic mineralization is strictly controlled by faulted structure in this deposit. This paper is based on geological and geophysical-geochemical integrated geological prospecting work in the deposit conducted by No. 306 Geological Party. Through analyzing the geological characteristics of the deposit as well as geophysical electric and geochemical soil survey, in combination with the rock (ore) physical characteristics within the deposit, the authors consider that the orebodies in this deposit have some obvious geophysical characteristics such as one high (high frequency) one low (low resistivity) and lead, zinc, copper, tungsten and other elements anomalous halos at the surface. Mineralizing potential in the depth of the Yantianqiao copper polymetallic deposit is synthetically evaluated, and the prospecting targets are delineated for future geological prospecting work.

A certain mining area is located in the middle of Wumeng Mountain area in northwestern Guizhou Province, which belongs to a contiguous special poverty-stricken area. In combination with the lead-zinc metallogenic background as well as the orebody characteristics in different depths (100~800 m), the authors chose the combination of such geophysical techniques as IP ladder sweeping, IP three pole sounding and audio-frequency magnetotellurics (utilizing two detecting devices for different depths, EH-4 and V8), deduced geophysical anomalies and guided the deployment of 10 drill holes, which all intersected industrial orebodies, thus expanding the lead-zinc reserves in the mining area. According to the application effect of the comprehensive geophysical prospecting method, the authors put forward some comprehensive geophysical prospecting methods which can tackle corresponding types of lead-zinc deposits in this area, thus providing guidance for further geological prospecting breakthrough.

The importance of carrying out geophysical prospecting work in the old mines is discussed in this paper. From the effectiveness and the capability for problem-solving, the reasons for carrying out magnetic method, charge method, transient electromagnetic method of integrated geophysical methods test were analyzed in this paper. The characteristics of the collection of the geophysical information in the cognition of geology by using different methods, the relationship between mineralization space and orebody, and the validity of prospecting were discussed in detail. The using of the principle of integrated geophysical work was proposed, in which the deep edge serves as the space, and the hydrothermal activity patterns, tectonic zone and contact zone serve as the object, thus expanding the surface and making key breakthrough.

Moshishan which is located in Jiayin of Heilongjiang province is volcanic rock distribution area.In order to research the characteristics about uranium deposit, we selected the ground gamma spectrometry method.By this method, we discussed the distribution characteristics of uranium anomaly in this region.It shows obviously effect on the uranium deposit prospecting and provides a way to prospect for uranium deposits.

In the past, the interpretation of oil and gas geochemical anomaly was primarily carried out by two-dimensional interpretation of plane and profile, which is difficult to accurately reflect the relationship between geochemical anomaly and subsurface oil and gas distribution. Taking oil and gas geochemical exploration in Meath Braque area of Kuqa Depression as an example and guided by vertical migration theory of oil and gas, the authors established a three-dimensional model for interpretation of geochemical anomaly (comprising three-dimensional model of geology, transportation space, abnormal pressure and geochemical anomaly) on the basis of the study of sedimentary-tectonic evolution, hydrocarbon generation evolution, oil and gas migration characteristics and abnormal distribution law. It directly reflects the oil and gas vertical migration, power source, migration space and migration pathway, and systematically explains the formation process of surface geochemical anomaly and its relationship with underground oil and gas in Meath Braque area. It is found that convergent migration of oil and gas caused by the bulge fracture surface leads to anomaly intensification, and divergent migration of oil and gas caused by the concave facture fracture surface results in anomaly weakening. Overall, the three-dimensional interpretation model for geochemical anomaly has achieved good results in Meath Braque area and it effectively improves certainty and accuracy of the geochemical anomaly interpretation.

Based on geochemical data collected along four profiles at different types of geological setting and soil parent materials from Longhai, Fujian Province, the authors studied the concentrations and distribution patterns of major elements and trace elements. The results show that chemical weathering is intense. A lot of elements such as Ca, Mg, Na, Si and K have been seriously leached, but Fe and Al have been accumulated. The weathering-leaching index (ba value) and the ratio of Si to Fe and Al (Saf value) of the study area under the warm and humid subtropical condition are much lower than the average values of the whole country. The weathering degree has reached the stage of Si loss and Al-Fe enrichment, especially for the soils derived from granite rocks. Soil environmental quality is quite good due to its relative low concentration of heavy metals. It is found that the concentrations of trace elements including heavy metals are mainly controlled by the parent materials, and their vertical distribution along these profiles is mainly controlled by major components and organic carbon, indicating significant correlation between them. The concentrations of trace elements along profile 1 derived from alluvial and marine sediments are much higher than those of other three profiles. The relative low concentrations of Fe, Al as well as heavy metals may be attributed to the leaching of fine clay particles by surface runoff and infiltration. Several kinds of heavy metals such as Hg, Cd, Pb and Zn show accumulation in top soils under bio-geochemical cycle and human activities. The relative enrichment factors of most heavy metals are less than 1, which means that the anthropogenic influence are not serious except for Hg and P.

Based on the data of the 1:200000 geochemical stream sediment survey, the authors delineated the single element contrast value anomaly by using the method of "subinterval area median contrast filtering" and "outlier contrast filtering" respectively. The overlap contrast value anomalies by the two methods were taken as a new anomaly border to re-delineate single element anomaly and multi-element association anomaly. This study indicates that, by the spatial overlay analysis of contrast value anomalies obtained by the two methods, the overlapped portion can be more effectively identified for the anomaly. According to anomaly characteristics of the concentration elements and regional geological background, It is held that this area has obvious potential mineralization and ore prospects of Au, Ag, Cu, Pb, Zn, Sb, Sn, W, and the prospecting work should focus on hydrothermal Cu polymetallic ore deposit, hydrothermal Pb-Zn ore deposit, hydrothermal Sb ore deposit, granite-type W-Sn ore deposit, porphyry Cu ore deposit and rock gold ore deposit.

Copper deposits in Guangdong Province are characterized by dispersion of occurrences, varied types and concentrated reserves. With eight typical copper deposits as examples, the authors investigated copper anomalies and element combination characteristics, and have reached the following conclusions:Copper enrichment position can better reflect the known ore deposit; Different types of copper deposits with similar sizes have similar copper anomaly areas, but their copper average values are different considerably; Cu, Mo, Sb combination of porphyry copper deposits, Cu, Pb, Zn, Ag, Cd, Bi, Mo, W, Sn, Mn combination of multiple genetic deposits and Cu, Pb, Zn, Cd, Ag, As combination of volcanic rock type copper deposits are fairly stable. These results provide some scientific basis for understanding of copper metallogenic regularity and carrying out geological survey and geological evaluation in Guangdong Province.

Audio magnetotelluric (AMT) method was employed to study the F2 and F5 branch concealed faults in Suqian sector of Tan-Lu fault zone. 4 AMT profiles were finished in the south of Suqian that included 176 AMT sites. By using advanced data processing and 2-D inversion called Non Linear Conjugate Gradients, the authors got reliable underground geoelectric models. In combination with the other geophysical data, the authors analyzed electrical structure and explained the location and attitude of F2 and F5 faults, and inferred that the activity of F5 faults is stronger than that of F2 faults. This result provides the basis of geological line selection and construction safety for Xusu-Huaiyan Railway.

In recent years, the authors have developed a kind of multifunction electrical system which is a new geophysical technology that has China's independent intellectual property rights.The system is suitable for exploration and study of such objects as metal mines, groundwater, geothermal activity and oil-gas reservoirs. In order to verify the effectiveness of the new technique's application capability in the hot sedimentary type deposits, the authors have developed IP and CSAMT experiments with this system on the Huaniushan lead-zinc deposit in Liuyuan area, Gansu Province. In high-power IP measurement, the authors delineated IP anomaly areas, and carried out evaluation analysis in combination with geological information. In the information section, the authors developed CSAMT method and obtained the underground electrical structure. Application results show that IP and CSAMT can reflect the ore-related geophysical anomaly, and thus can serve as a model for the exploration of the same type of deposits.

In the forward modeling of transient electromagnetic response, the commonly used method is to calculate the response in the frequency domain, and then the results were converted into the time domain. In this paper, five frequency-time conversion methods (Digital filtering algorithms of sine and cosine transform, G-S inverse Laplace algorithm, polygonal approximations method of sine and cosine transform) were used to conduct calculation. it is concluded that the digital filtering method based on cosine transform has the highest computing precision among these five methods, as shown by the comparison with the analytical algorithm, and the reasons of the error caused by these five kinds of conversion methods were discussed and analyzed, which is beneficial to the high precision calculation of one-dimensional forward modeling of transient electromagnetic response, so that these methods can be better applied to the calculation of multi-dimensional frequency-time conversion.

Traditional seismic data sampling must follow the Nyquist sampling theorem;nevertheless, the field data acquisition can't meet the sampling theorem due to missing traces or exploration cost limits, so we need to reconstruct prestack data to meet the requirements for subsequent processing.A seismic data reconstruction method based on the Projections Onto Convex Sets (POCS) algorithm and a complex-valued curvelet transform (CCT) has been introduced in the paper.Firstly, the Projections Onto Convex Sets (POCS) and complex-valued curvelet transform to characterize the local features of seismic data have been introduced.To tackle the disadvantage of slow convergence in traditional threshold parameter during the reconstruction process, the authors also propose an exponential square root decreased threshold and process 2-D seismic data reconstruction with the hard thresholding, which can reduce iterations and improve reconstruction efficiency.The case study of synthetic seismic data shows that the effect of this method is fairly good.The authors applied this technology in real seismic data and obtained a good result.

In seismic numerical simulation, the perfectly matched layer (PML) boundary can attenuate the seismic wave effectively, and the snapshots and record have no boundary reflection interferes.The authors further analyzed the attenuation mechanism of split perfectly matched layer (SPML).By wave equation simulation, the authors analyzed the problem as to how the parameters affect absorption and attenuation characteristics of SPML boundary, such as source dominant frequency, spatial grid spacing and medium speed.As a result, the authors obtained the results of PML attenuation based on different conditions.Through analyzing and comparing the results, the conclusions have been reached that source dominant frequency has no direct influence on PML attenuation, spatial grid spacing is in inverse proportion to the PML attenuation, and high-speed medium slows down PML attenuation effect.By Marmousi2 test, the authors confirmed the validity of the conclusions.The selection method of SPML parameter in complex model or different scales of numerical simulation was given, which lays a foundation for quantitative selection of SPML boundary parameters in numerical simulation.

The quality of seismic image of underlying strata is negatively affected by shallow gas. Therefore, it is difficult to predict the depth of target zone accurately. Thus the drilling risk of horizontal wells is greatly raised as well. In order to improve the accuracy of depth prediction, we use theoretical model analysis to quantize the gas influence including the range and extent. Furthermore, we build many models to achieve pre-stack forward modeling and acquire a series of correlation templates which can be applied to quantitatively depth correlation. According to our research, we successfully explain why there exits so large depth difference between two drilled wells in B oilfield. Furthermore, we compute correlation templates to achieve a high-precision depth prediction for underlying reservoir of shallow gas. Therefore we efficiently guide the drilling of follow-up development wells. We believe our research production will be well used in other offshore oilfields containing shallow gas as well, especially under the condition of sparse well patterns offshore.

The signal-to-noise ratio (SNR) of raw data from seismic exploration in the metallic deposit is very low, and various sorts of interference waves are mixed in the record, which seriously influences the quality of image formation for mineral seismic data.Therefore, an effective method of de-noising is the key to improving data quality.Based on seismic-data processing of the Kalatongke copper-nickel deposit in northern Xinjiang, the authors adopted multi-method combinational de-noising of FOCUS5.4 software to suppress mono-frequency noise, acoustic interference, surface wave and mechanical oscillating interference.Based on module experiment and parameter test, the authors found noise removal methods which are adapted to the contact mineral zone.This de-noising processing improves greatly SNR of mineral seismic data.

Time-lapse seism is an important technology for prediction of remaining oil prediction;Nevertheless, due to the need of repeated acquisition of seismic data, the application range of the strictly sense time-lapse seism is subjected to certain restrictions.According to the actual situation of the implementation of the two times of acquisition in high exploration degree oil fields in China, this paper puts forward the non-uniform time-lapse seismic technology.The research train of thought was established with the consistency of the two times of data processing as the basis, mutual constraint processing as the core, and the differential attribute extraction as the purpose.The key technology for elimination of non-reservoir differences between the data was studied, and a non-uniform acquisition of time-lapse seismic processing flow was formed, which maximally eliminates the influence caused by non-uniform acquisition.The technology was applied in YX oilfield, and the result proves that it has a good prospect.

The methods based on coherent and variance are used to determine faults, which take advantage of the strong signals in seismic data; nevertheless they are limited by seismic resolution and hence fail to accurately identify small faults. In the seismic data, the boundary of large-sized geological body has obvious reflection characteristics. However, in the case of smaller geological bodies such as pinchouts and small faults, their weak reflection energy exists in the form of diffraction or residual diffraction, which is overwhelmed by the strong reflection. In this paper, plane wave destruction method is used to extract diffraction. The reflected wave angle body is calculated using regularization iterative algorithm. And then the mean filter method is used to extract strong energy reflection, which is subtracted from seismic data to get the diffraction wave information. Using diffraction wave information, we can decide the development extent and combination style of the faults. Theoretical model analysis and actual data application show that this method is practicable and effective in identifying faults. This method has a certain value for industrial application.

Topography has a great influence on the inversion and interpretation of magnetic anomaly, especially where the abnormal body is distributed close to the ground.In order to reduce this influence, the authors deduced limited-deep two-dimensional thick plate forward formula under the rugged topography, and put forward a new method to divide the underground objects under the rugged topography.In addition, focusing inversion has good focusing effect for physical property;if we can predict that the magnetic anomaly is caused by ferromagnetic body, then focusing inversion can be applied to obtain better situation.It is obvious that this method is suitable for the inversion of ferromagnetic body.The authors combined two-dimensional magnetic anomaly forwarding and focusing inversion under the rugged topography, and carried out corresponding model test, then compared this method with focusing inversion under the flat topography with max smoothness inversion under the rugged topography, and the results show the effectiveness of the method put forward by the authors.Finally, the authors applied the method to magnetic anomaly profile obtained from Tex, Xinjiang, and made a reasonable explanation for the ferromagnetic body.

The TEM instruments have provided a hardware foundation for three-component TEM interpretation; nevertheless, the practical interpretation technology is still confined to the vertical component or simple approximation techniques. To make full use of the three-component data and improve the resolution of the fixed source TEM, this paper put forwards the three component full domain apparent resistivity definition and one-dimensional three-component joint inversion method. For the full domain apparent resistivity definition, the authors use the iterative method to calculate the inverse function value instead of directly calculating the inverse function. The authors introduce the three-component weights of TEM data to build the joint objective function, and use the feasible region method to implement three-component joint inversion. Finally, the three-component interpretation algorithm is applied to the model calculation and the actual exploration data of the metallic mine to verify its effectiveness. Model test and actual data processing results show that the three-component interpretation method can use more TEM data and obtain processing results with higher resolution, thus achieving a fast calculation speed.

Hard rock-hosted uranium deposits in southern China constitute an important producer of uranium ore districts. In the past years, a lot of EH-4 measurement work was carried out; nevertheless, during the information processing in the application process, complex external conditions in southern China makes it difficult to perform explanation. In this paper, with a line of the Shazijiang deposit as a study case, the authors analyzed some EH-4 measurement problems, and tried to use such means as spectrum file reading, impedance tensor decomposition, and static correction and terrain correction on the basis of the MT-Pioneer software. The authors conducted a two-dimensional inversion, and the inversion results were consistent with the features of actual geological body, thus providing a reference for future EH-4 data processing in such areas.

The marine electromagnetic method has been widely used in physical oceanography, geophysics and underwater target detection. These applications should be based on high precision electromagnetic signal observation in the marine environment. The ocean bottom electromagnetic receiver designed for high precise ocean bottom electromagnetic observation should overcome some technical problems such as high reliable release and recovery, high stable underwater operation, low noise level, high dynamic range, and low time drift. The research experience and results as well as the latest developments of ocean bottom electromagnetic receiver from China University of Geosciences (Beijing) were reported in this paper. The new ocean bottom electromagnetic receiver's indicators are as follows:typical E-field noise:0.1 nV/m/√Hz@0.5 Hz; dynamic range:higher than 110 dB; clock drift:lower than 5 ms/day, in line with advanced receivers of other countries. By early 2016, ocean bottom electromagnetic data acquisitions on about 60 sites had been completed. Since 2012, the receiver's recovery rate has reached 100%. A lot of high-quality ocean bottom magnetotelluric data as well as controlled-source electromagnetic data were obtained by these receivers, which have been successfully used in oil-gas and hydrate explorations.

The high accuracy calibration method for the system characteristics of geophysical prospecting instruments based on correlation identification is proposed in this paper.The inverse repeated M sequence is used as the excitation signal, the measurement channel of the instrument is disturbed with encoded input current, the excitation current and instrument response output in time series is recorded according to the same sampling rate, and then circular cross-correlation method is used to obtain the instrument system frequency response.The simulation results show that the frequency resolution of the instrument system is improved by using the method based on encoding source, the multi-period excitation can significantly improve the accuracy of identification, and the right sampling rate is also helpful to improving the accuracy of identification, but it should match with the system data storage capacity.

Because the gradient tolerate of the traditional proton magnetometer on the low side, so that cannot be guaranteed accuracy of magnetic survey in the region of geomagnetic field is inhomogeneous to resolve this difficulty, this paper deeply research the feasibility of enhancing gradient tolerate of the proton magnetometer by improved method of measure signal cycle.And filtrate powerful functions 32 bit embedded ARM IC as main control unit, developed new type high precision proton magnetometer.Through comparison test with CZM-5 proton magnetometer, prove the index of gradient tolerate of the new type high precision proton magnetometer not lower than 8 000 nT/m, satisfy design requirements of the project assignment book.Conclusion is that improved method of measure signal cycle can notably enhance gradient tolerate of the traditional proton magnetometer that is important technology index.

This paper introduces the application of TRIZ theory to improving the process of solid carrier element extractor. First the advantages and disadvantages of the existing elements extractors are pointed out, the ideal solution is proposed, and the invention theory is innovated to improve the design of the conflict matrix. The improved ball element extractor expands the contact surface with the surrounding soil to the maximum, and can be better adapted to the characteristics of electric field, thus providing a more convenient and broader channel for the electric active material in the soil to enter the extractor and hence maximizing the efficicney of the electric extraction process.

The airborne gravity vibration reduction system is an effective way to attenuate high frequency vibration in the airborne environment, thus improving measurement accuracy of aviation gravity.Therefore, the primary problem in the design of the vibration reduction system is to set up such important parameters as reasonable stiffness, damping, and quality.The authors established differential equations of motion for two types of vibration reduction system of airborne gravimeter.With theoretical and investigate instances, the authors discussed vibration reduction system model, with the purpose of in-depth understanding of the law of airborne gravity vibration reduction system and providing the necessary theoretical support for its parameter design.

In airborne gravimeter and ground gravimeter measurement unit, there often occur drift phenomena.If this drift is regarded as a linear relationship, the first and last data are used to do drift correction process.Nevertheless, the airborne gravimeter structure is complex, and the sensor drift is caused by many factors, with the most critical factor being the environment temperature change disturbance.It is impossible for us to avoid airborne gravity dramatic changes in the temperature difference of flight measurement between summer and winter.The authors used the airborne gravimeter static data as an example.First, the data need gravity tide correction and drift correction by using a least squares method.Secondly, correlation analysis is used to analyze the static data and instrument thermostatic temperature to obtain a strong correlation characteristics.Finally, linear regression equation is set up to calculate the static data and, as a result, the gravity of the final corrected precision is greatly improved.This correlation analysis method has practical significance for the in-depth understanding of sensor drift correction methods and pre-study of dynamic measurement data in the drift correction.