Based on systematic collection of rock and ore samples in 11 drill holes along No. 7 and No. 9 exploration lines in the Huogeqi copper-polymetallic ore district of Inner Mongolia, the authors drew contour map of primary halos, established vertical element zoning sequence and, in combination with variation characteristics of the indicator elements, made a prediction of concealed ore bodies in the depth. The ore-forming element association of this ore deposit is Cu, Pb and Zn, the front halo is composed of Hg, Sb and Cd, whereas the rear halo comprises W, As and Sn. As this ore deposit lies on the overturned limb of an inverted syncline, the vertical zoning sequence of elements is mainly of reverse zoning, and the variation characteristics of vertical zoning and indicator elements suggest that the ore deposit is characterized by multi-phase and multi-stage repeated superimposition. There exist at least two phases of ore-bearing fluids along No. 2 exploration line, and there might exist blind ore bodies in the depth of ZK702, ZK830, ZK726 and ZK817 drill holes.

According to the exploration results of two magnetotelluric sounding profiles in central Guangxi area, the authors have studied the geological structure of central Guangxi depression and its surrounding areas. Central Guangxi depression is divided into four sub-units, i.e., northern slope, western slope, central depression and eastern slope. The depression was developed on the basis of lower Paleozoic epimetamorphic rock series, and the average thickness of Devonian strata reached 4 000 m. The electrical characteristics show that the Middle-Lower Devonian strata constitute the main horizon of the biogenic reef, and the electricity is characterized by relatively stable low resistance. Two-dimensional inversion of the section has revealed an electrical anomalous body with the character of "high in low", which is inferred to be a reef. Brachyanticlines are well developed in the central depression, and hence the central depression and its surrounding areas are considered to be favorable areas for oil and gas exploration.

Ulgoin basin belongs to the Middle Cenozoic volcanic rock area outside of the Songliao basin. For the purpose of investigating the potential distribution of the sedimentary basin and tectonic framework, the utilization of such means as gravity, magnetic survey, magnetotelluric sounding and other non-seismic geophysical methods is helpful. These methods provide the basis for evaluation of the oil and gas resource potential. Based on an analysis of the physical characteristics of rock strata and taking advantage of the gravity, magnetic survey and electrical method, the authors carried out comprehensive interpretation and determined the distribution and tectonic framework of Cretaceous Bayanhua Group and Jurassic morphology. It is pointed out that the Ulgoin rift basin has a good prospect in the prospecting for oil and gas resources.

Based on systematic measurement of the distribution of acidolysis hydrocarbon in well log with unconformities of different epochs and different depths, the authors found that under the unconformity surface there is an abnormal distribution zone of hydrocarbon which has low total abundance of hydrocarbon, low concentration of methane and relative enrichment of hydrocarbon macromolecules. It is considered that this anomalous zone is a degassing zone formed by weathering and degassing, and its thickness is related to the diagenetic degree of the lower strata. This discovery has great significance for evaluating the relationship between the basin erosion and the gas reservoir preservation or destruction as well as for studying the effect of the unconformity on oil and gas migration, and also provides a new scientific clues for solving the problem of restoration of denuded strata.

Comprehensive 5-direction IP logging is one of the important methods for exploration of sulfide type ore deposits. Blind and concealed ore bodies can be found by using its advantage of high SNR and on the premise of understanding the physical parameters. The practical example of the exploration of a Cu-Fe polymetallic deposit in Houa Phan Province of Laos shows that the 5-direction IP logging curve is in accordance with the drilling result. The enrichment sectors of pyrite and chalcopyrite are all associated with high polarization anomalies, and a comprehensive analysis can determine the position of the blind ore body. This exploration is a successful case of discovering hole bottom blind ore body under the guidance of 5-direction IP logging.

Based on a study of the geochemical characteristics response of different scales of gold element data from 1∶200000 geochemical survey in the middle-lower reaches of the Yangtze River, the authors hold that there exists a giant geochemical province in the middle-lower reaches of the Yangtze River, which has continuously provided ore sources for the middle and lower Yangtze River areas. The feasibility of applying the low-density geochemical method to whole China or the whole world is also discussed in this paper.

Making use of the ideas and methods for interpretation of cracks,the authors employed the multi-information gravity and magnetic and remote sensing technology. The concept of linear body field of remote sensing was introduced into the interpretation of linear anomalies and linear structures of the geophysical field. The study areas are two carbonate oil fields: the Zhanazhol, Kenkiyak oilfields located in the east part of Precaspian Basin, western Kazakhstan, and the Yurubcheno-Tokhomskoye oilfields located in the west of Baykit Basin in eastern Siberia. The characterization significance of macro-cracks and fractures of the geophysical linear body is explained, the quantitative method is analyzed, the distribution features of the geophysical field and linear body of Aktobe region are studied,and the development pattern of macro-cracks in this area is established.

A compatibility test of the chemical elements in the surface environment of Inner Mongolia has revealed that the 1∶200 000 regional geochemical survey can provide all kinds of geological information in the primary environment, especially the reconnaissance and prospecting information. The geochemical data quality can be ensured through data leveling processing for eliminating the major systematic errors in the test results of regional geochemical elements. Information provided by maps, such as the maps of ln(w_Cr×w_Ni×w_Co), can be used to make geochemical divisions and also serve as valuable reference for basic geological study. Based on the regional geochemical map, the authors delineated geochemical metallogenic areas of chemical elements in Inner Mongolia, which could provide important information for geochemical metallogenic prognosis.

This paper briefly describes the definition of the normal gravitational field and the parameters that affect its value, compares the 1980 normal gravity formulae and CGCS2000 normal gravitational field parameters, makes a comparative analysis of the normal gravity and CGCS2000 normal gravitational field parameters used frequently in present gravitational exploration work, and deals with the necessity of popularizing the new normal gravity formulae in regional gravitational survey. A comparison between the normal gravitational field formulae deduced by four parameters of CGCS2000 and previously used normal gravitational field formulae shows that the former formulae are more scientific and advanced and can more accurately reflect real earth gravitational field.

Based on data of some gas components in drilling mud at 350~800 m interval of No. 2 borehole for WFSD and Richter earthquake magnitude M_L≥3.5 catalog as well as lithologic character of cores from the faulted zone of Wenchuan earthquake, the authors investigated the relationships of anomalies of drilling mud de-gas gaseous components to tectonic environment and earthquake activity. The results show that the shattering of rocks is maximum at the interval of 660~680 m, the normalized values of various gases also show obvious positive and negative anomalies, and the intervals corresponding to the maximum and minimum values are places where aftershocks higher than the magnitude M_S 3.0 frequently occur. The gas anomalies mostly occur in cracks in rocks, surface of fractures and faults.

This paper deals with three gravity satellites, namely CHAMP, GRACE and GOCE. Satellite gravity data are widely used in such fields as the recovery of the earth's gravity field, the land water storage, the study of the geoid change, the elastic thickness, the crustal thickness, the gravity variance before and after earthquake and the crustal movement. Lots of successful and valuable research results were obtained. It is considered that the satellite gravity survey technology is by for superior to traditional gravity survey and will surely have larger application space.

The longitudinal conductivity is one of main parameter in TEM method, but it rarely be used in base metal geophysical prospecting due to many causes.In this paper,a new deduced parameter— is defined and its algorism is proposed. Parameter is a first relative value in TEM.A lot of results of modle caculations and measured data processing are as same direct 1D inversion as apparent resistivity's. But the caculation is so easy and the solution is unique. ΔS_τ^rt could be used in center-near zone for in-loop and coincident loop configuration data processing.

The HTc SQUID magnetometer is characterized by lower noise, wider frequency ranges, higher-response to low frequency and it can be used as a B field sensor in LOTEM. The results of the field tests of HTc SQUID applied in LOTEM show that the HTc SQUID magnetometer has superiority over conventional inductive coil. Applying the HTc SQUID in LOTEM will promote the depth of investigation and it will be a new instrument in geophysical exploration of the deeper resource.

This paper discusses the principle and method of the high-density electrical method. Using the high-density electrical method, the authors investigated geological landslide in Chayuangou area of Gaochuan, Sichuan Province. In combination with the borehole data, the position of the main sliding surface, the buried depth of the bedrock, and the water level for landslide were determined, thus providing reliable geophysical basis for tackling the landslide.

In the field of geophysical exploration, great attention has been paid to the utilization of the streaming potential characteristics in reservoir rock to describe the flow characteristics of the reservoir. According to the electrical double-layer model and the electrochemical theory, the authors derived the coupling relationships between flow field, ion field and current field based on the capillary model. The influences of pore structure parameters on the coupling coefficient of streaming potential were obtained by numerical simulation. The results show that, when the influence of the concentration polarization effect on streaming potential is considered, the absolute value of coupling coefficient of streaming potential increases with the increasing solution concentration, cation exchange capacity, porosity and permeability. In addition, the concentration difference polarization amplifies the streaming potential.

Based on an analysis of seismic data collected with different acquisition parameters in a work area of the South China Sea, this paper deals with the impact of the sinking depths of seismic source and cable on the quality of collected data in marine tow seismic exploration. The results are as follows: the shallower the seismic source sinking depth, the better the high frequency effect with the broadening wavelet frequency band; the shallower the cable sinking depth, the broader the frequency band, and the higher the resolution ratio, but with rather high noise resulting from stormy waves. The results obtained provide good basis for seismic data acquisition and subsequent seismic data processing.

Using the advantages of NMR logging data such as large amounts of information, convenience, visual data interpretation and high application potentiality in combination with the conventional logging data, the authors made integrated interpretation of the well logging data. The processing and interpretation of the practical data show that this method can obviously improve the reliability of the formation liquid property evaluation and help solve the logging evaluation problems for some complex formations.

This paper proposes the utilization of the magnetic probe that has larger receiving area to replace the air core coil which has too small receiving area. This design was realized in Datong, Shanxi Province. The authors used the improved arrangement in search for Mo deposits in Tibet, where the detection depth could reach 1 000 m, far larger than the detection depth of the traditional receiving system. The experiment and application of the improved receiving system make the application of TEM to oil and deep ore exploration feasible.

With real seismic data, this paper makes the model restrained by top and bottom. The tops are positions which are interpreted along lineups skipping phases in an apparent cycle and following lineups strictly. The bottom is a position which is interpreted along lineups automatically. Through comparing the slices in different models, the authors studied the effect of time-crossing on strata slice. The findings show that slight time-crossing has a certain effect on strata slice, but will not affect the whole state of lithofacies distribution. Instantaneous amplitude is not related to instantaneous phase. When time-crossing is higher than 3/4 of a apparent cycle, the whole state of lithofacies distribution in strata slice with instantaneous amplitude will be affected. If the extent of time-crossing is greater, the effect will be more obvious. The effect of time-crossing on strata slice is connected with the size of the time window and the characteristics of seismic attributes. The smaller the time window is, the more obvious the effect is. A comparison with instantaneous attributes shows that, when the seismic attribute in strata slice is a statistic one, time-crossing will have a slight effect on strata slice.

In order to design a new multi-wave and multi-component seismic exploration system, the authors analyzed some problems in applying DTC-150, obtained the effective frequency range of coal rock and the effective layout plan of the observation system on the basis of analyzing large amounts of engineering forecast data in combination with studying four key technologies, developed a high speed and high precision multi-channel data acquisition and processing system, gave the blind spot where the working face diffraction echo is formed and the tunnel sound wave processing method, and proposed the conditions under which the working face diffraction echo and the direct wave do not overlap. The new multi-wave and multi-component seismic exploration system will provide accurate and long-distance advanced detection method for the mine and also offer the powerful guarantee to safety production of the mine.

This paper analyzed the 1∶50000 rock-scrap data obtained from northwestern China, using the R-mode factor analysis method. Geochemical subdivisions were carried out with the extracted five representative factors from the data. Then the authors decided factor F3 (Cu-Zn-Ag) which was related to mineralization, in comparison with regional mineralization characteristics, geological conditions and mineralization in the study area. Geochemical anomalies were extracted with the factor analysis method based on MAPGIS digital elevation model. The result suggests that the anomalies are well consistent with 76% Cu mineralizations, raising the efficiency by 10% in comparison with the single element copper geochemical anomalies. The main anomalies are located in Gongpoquan Group, particularly in the contact zone with parts of magmatic rocks. Mineralizations were found in most of the anomalies. In addition, some small anomalies were found in the K-feldspar granite, and field anomalies inspection has proved that these anomalies are caused by limonitization and malachite of quartz veins and K-feldspar granite. The project of trench has also proved the superiority of the method in the medium-large scale anomaly extraction.

Selenium speciation in root soil samples collected from the Poyang Lake basin of Jiangxi Province was investigated in this paper. The results show a significant positive correlation between the species and total amounts of selenium in root soil. The residue species of selenium occupies 12.32% of total selenium, and the species of bound-state humic acid approximately accounts for 66.23% of the total amount of selenium in root soil. Meanwhile, selenium abundance in root soil insignificantly varies with the change of pH value but is significantly influenced by organic content. It is held that the process of selenium adsorption in soil organic substance and clay mineral causes selenium enrichment in root soil. This paper has proposed a method for estimating speciation concentration of selenium according to the total selenium and established a formula to calculate available selenium content with given data of selenium abundance and speciation in soils. In addition, a suggestion is put forward that only selenium species of organic bound, residue, water soluble and total amount of selenium should be considered in soil selenium assessment.

This paper describes the basic idea of isolation technology of CO₂ and the main mode of isolation of CO₂. On such a basis, the authors proposed the feasibility of seam separation and isolation of the mechanism for CO₂ and analyzed the key research questions and research ideas of geological storage of CO₂ in seam, with emphasis placed on the availability of seismic monitoring in CO₂ storage.

This paper presents a fast forward calculation method of gravity and magnetic anomalies for 3D arbitrary bodies based on GPU. The surface is subdivided into a large number of regular voxels. For any 3D arbitrary body, the total volume can be combined by these voxels with fixed size and unknown physical properties (density or susceptibility). The gravity (magnetic) anomaly of these voxels at the surface points can be computed by the analytical method. The sum of the above gravity (magnetic) anomaly of each voxel can represent the anomaly of the whole arbitrary body. For the purpose of improving the approximation, the subsurface should be divided into a larger number of voxels. The authors have adopted GPU parallel method for forward calculation because the traditional CPU program is time-consuming. The result shows that the forward calculation by GPU has correct results and improved efficiency. The idea can provide the basis for 3D inversion of gravity and magnetic anomaly.

This paper introduces a method for studying the effect based on high-order statistics of GPR data. The basic idea of this method is the utilization of high-order statistical parameters in signal recognition and detection for processing and reconstruction of different models for GPR records. The model test shows that there are different high-order statistical features in different models, and the high-order statistics show obvious effect on suppressing background noise and multiple reflection of GPR data.

This paper deals with methods and properties of Tilt-Euler deconvolution by analyzing the theoretical model and the measured gravity data. The results show that the Tilt-Euler deconvolution method can rapidly provide automatic estimation of the source location and source type from gridded gravity or magnetic data on condition that no structural index is required, and can also automatically estimate the structural index. With simple calculation and high practical use, this method is of great significance in large-area aeromagnetic and airborne gravity data processing and interpretation.

Popov adjustment programs for gravity base-point net adjustment is implemented with VB language. For the purpose of taking advantage of software Surfer's function, Popov adjustment programs transfer Surfer to automatic plot gravity base-point net adjustment. Practical application of Popov adjustment programs proves its features of convenience and accuracy; in addition, Surfer automatic plotting can make plotting efficient and perfect since it avoids manual plotting.

The problems encountered in the application of tilt derivative method to aeromagnetic data processing have been analyzed in this paper. Influenced by the shallow-source interference field, the shape of the aeromagnetic data anomaly processed by the tilt derivative method is complex. An improved method that combines the upward continuation with tilt derivative is therefore put forward in this paper. With practical examples, this paper deals with the problems that are worthy of attention in the application of tilt derivative method to aeromagnetic data processing. The improved method can fully manifest the advantages of the aeromagnetic data in the aspect of geological data interpretation.

For supersonic detection, the physical property of the measured media can be identified by using such kinds of acoustic information as the acoustic time, amplitude, frequency and waveform. The first three kinds of information can be measured based on quantitative or semi-quantitative mathematical expression, whereas the last one cannot be quantitatively interpreted. In order to study the variation of the waveform, the authors made a test by using the model test block. The test results show that the waveform of received signal is basically similar to that of the launching wavelet for the homogeneous media, which is consistent with acoustic boundary conditions. The mutation of received signal can result from the foreign body (defect) existent in the media. It can be explained based on the laws of refraction and superposition, so as to summarize some regularities and propose a quantitative method for quantification.

borehole acoustic testing is an important in situ geotechnical engineering geophysical testing project. But during the test and test methods and equipment layout parameters selection, elastic wave identification, integrity coefficient calculation, and test results of engineering applications, such as wave column contains geological information and the application of the wave velocity and integrity of the relationship, testers not easy control and very questionable. Therefore, it is necessary, the above problems are discussed, with wants to improve investigation technology level.

According to the principle of TGP tunnel geological prediction system and the problem existent in the process of detection, this paper has discussed some abnormal-signal-induced factors such as external pulse signal interference, current interference, poor coupling, pipe wave and charging parameters in the data collection, and analyzed the cause of resultant errors with the feedback from engineering application. On such a basis, some suggestions were put forward on improving the understanding of anomalous seismic wave and geological work as well as edge diffraction wave for avoiding the abnormal signal generation and reception. It is concluded that the collection of reliable data is an essential and efficient way to improve the accuracy of TGP system data interpretation.