Grounded-source transient electromagnetic method (TEM) has many advantages such as deep exploration, flexible arrangement in rough terrain and high working efficiency. Recently it has got much attention and a series of new methods are available, ranging from surface to airborne and borehole method. In this paper, the authors review the research history of long-offset TEM (LOTEM), short-offset TEM (SOTEM), multi-channel TEM(MTEM), grounded-source semi-airborne TEM and grounded-source surface to borehole TEM, and summarize their research status in forward modeling, system design, inversion, imaging and field working. The results show that, as a well-developed grounded-source TEM, LOTEM has accumulated many research achievements. Although some progress has been made, the researches on other grounded-source TEMs are still in a primary stage and still need further improvement. Valuable research results in LOTEM, for example, noise suppression technology, high dimensional inversion and point interpretation, can be introduced to these newly developed electromagnetic methods, which can help provide solutions for high working efficiency and high resolution deep exploration.

Due to historical reasons, the present coordinate systems of the geological, geophysical and geochemical exploration results are basically WGS84, BJ54 or XA80 systems; nevertheless, according to the NASG requirements on the overall use of CGCS2000 coordinates, in the future the coordinates for all kinds of results should be CGCS2000 coordinates, which causes inconvenient situation in using the results and in comprehensive research work. As a professional geographic information system software, ArcGIS has a wide range of applications in various walks. In this paper, the authors briefly introduced the ArcGIS built-in coordinate system, studied and deduced the calculation formula of the MOLODENSKY coordinate conversion method in ArcGIS, put forward the method to get the conversion and precision evaluation of transformation parameters between different ellipsoids, and cited practical examples for verification. On such a basis, the specific ideas and points for attention were analyzed for each coordinate system in the conversion of ArcGIS software to CGCS2000.

Based on a brief description of the basic principle of the Acoustic Doppler Current Profiler (ADCP) and exemplified by some typical environmental monitoring engineering cases, this paper gives a brief account of the achievements made by this technique in such engineering fields of Hong Kong as marine environmental quality monitoring and marine engineering environmental evaluation. The practical engineering application shows that the adoption of ADCP technique could yield satisfactory environmental monitoring result. The importance and effectiveness of applying this technique to environmental quality monitoring is also explained.

Studying the occurrence of natural gas hydrates (NGHs) is of profound significance for NGH exploration. The evaluation of the NGH saturation mainly relies on the Archie equation using the electrical parameters of rocks. The key to accurately calculating the NGH saturation is to select corresponding values of rock electrical parameters for different geological environments, especially the porosity index (m) and the saturation index (n). However, it is still a challenge to select the optimal m and n values for NGH evaluation in resistivity logging. To ascertain the relevant resistivity regularity of NGHs and the determination method of rock electrical parameter values in the Archie equation, this study systematically reviewed relevant references and summarized the resistivity influencing factors of NGHs. Moreover, this study analyzed the influencing factors for the accurate evaluation of the NGH saturation based on the Archie equation. Accordingly, this study generalized the resistivity characteristics of NGH-bearing sediments and proposed the application research direction of the Archie equation.

This paper has summed up the progress of the ERI method over the past decade of years as well as its future development trend in the following aspects: ① A comparison of the performances of the main ERI instruments used at present shows that the ERI instruments tend to develop in the multi-channel, multi-parameter, multi-functional, high-power direction; ② ERI measurement environment has changed from surface measurement to water surface, underwater and cross-hole measurements, with the last three kinds of measurements analyzed in this paper; ③ On the basis of analyzing ERI data processing method and inverse development status, this paper describes three-dimensional and four-dimensional inversion theory of ERI with practical examples; ④ ERT applications are summed up, and several new applications are introduced. It is concluded that, with the improvement of the probing depth and observation precision as well as the diversification of the observation models, the application field of ERI will become broader and broader, and this technique will surely have wide development prospect.

Investigation and evaluation of the natural radiation level of Qingdao City were conducted by Qingdao Institute of Marine Geology from 2003 to 2005. The radioactive level of Qingdao City remains within the safe range of the natural background level, although the average dosage rate of the terrestrial γ-radiation is slightly higher than that of the National and Shandong Province Standard. The level of the terrestrial γ-radiation seems on the whole controlled by the local rocks. The terrestrial γ-radiation results from ²³²Th, ²³⁵U and ⁴⁰K, while ⁴⁰K or/and ²³²Th contribute more to the terrestrial γ-radiation than ²³⁸U, which is different from things of the other areas. In addition, the amounts of radionuclide contained in such materials as masonry, cement and concrete used for many construction projects like roads and architecture affect the level of terrestrial γ-radiation of the construction projects.

This paper analyzed the twin-T notch filter circuit, deduced the expressions of transfer function, center frequency, bandwidth and Q value. Through calculation, analysis and simulation, the optimal resistance and capacitance were selected for the characteristics of wide field electromagnetic signal and the suppression requirements of frequency interference. Experiments show that the optimal design of twin-T notch filter's minimum depth of suppression is -31.9 dB when the bandwidth is only 3.62, so the application of the optimal design of twin-T notch filter can not only keep the desired signal, but also maximally filter out frequency and its harmonic interference noise in the wide field electromagnetometer.

Geological database has been widely used. In the whole geological database, geochemical database occupies an important position. Geochemical database can be classified into 6 types, namely, solid ore geochemical database, oil and gas geochemical database, isotope geochemical database, agro-ecological environmental geochemical database, geochemical analytical database and standard reference materials database. The present conditions, applications and development trends of geochemical database have been analyzed and discussed in this paper.

Fluorescence spectrometry is commonly used to determine polycyclic aromatic hydrocarbon and evaluate the migration of oil and gas as well as the properties of base oil. Lying in western China , Xinjiang is almost covered with snow in winter. According to the geographical climatic environment in combination with the low detection limit and high sensitivity of fluorescence spectrometry, the authors analyzed the snow and the soil below it along a profile in a known oilfield in Xinjiang by means of fluorescence spectrometry. The results of two-dimensional fluorescence spectra, constant-wavelength synchronous fluorescence spectra and three-dimensional fluorescence spectra are compared with each other and discussed in detail. The comparison results shows that snow can quite effectively adsorb the polycyclic aromatic hydrocarbon and have an abnormal indication for the oil and gas reservoir. These findings can provide some reference for the exploration of oil and gas reservoirs in unknown geographical climatic environment areas in the future.

Starting with algorithm designing, training image,and practical application,the authors analyzed multiple-point statistics research trends both in China and abroad.On such a basis,the core principles of the main four MPS algorithms,their applicable ranges and advantages as well as disadvantages were analyzed,so as to forecast the trend of reservoir modeling.Multiple-point geostatistics is an international forefront research tool in stochastic modeling;nevertheless,as the algorithm is not yet mature,it should be further improved.On the basis of previous researches,the existing problems of the multiple-point geostatistics that need to be modified and the direction of the processing of training images are proposed,such as suitable processing of training image,choice of similarity methods,choice of standardized data,smoothing,coupling among algorithms,and expansion of the simulation extent for fractured-vuggy carbonate reservoir.In order to improve the usage of multiple-point geostatistics for reservoir stochastic modeling,we should spare no efforts to increase the simulation area,improve simulation accuracy,expand the scope of simulation of reservoir types,save simulation time and improve simulation efficiency.

The high-resolution position data in the centimeter grade are extracted from the binary output records of the hand-held GPS position indicator, and the multiple average measurement and post-operation position difference correction method are used so as to decrease the planar locating error of the portable and cheap hand-held GPS position indicator from several meters to 1 m or so. Thus the precision of the sub-meter grade can be attained.

This paper advances a new data processing technique-subregion median contrast filtrering method.It uses subregion to simulate spatial variation of the background, calculates critical values of anomalies with EDA technique, and measures the undulation of field values with the contrast as the datum. This technique fairly satisfactorily solves the problem of recognizing weak anomalies, and the preliminary application proves it to be effective.

Traditional sectional view algorithm lacks accurate processing capability for such phenomena as pinch off, absence, and lenses of strata. The accuracy of the algorithm can hardly meet production requirements. To solve these problems, this paper proposes an auto-matching algorithm for building geological sectional view by stratigraphic distribution pattern. First, the project drilling data structure is built; then, based on the distribution of strata, the patterns of strata are defined and the section line growth policies and rules of each model are deduced. From left to right, from top to bottom, the sequence stratum pattern matching method is used; according to the problem as to which section line the stratum point belongs to is determined; finally, the section line sets of points are connected into the line, thus finishing map annotation and map decoration. The algorithm overcomes the problem of poor continuity existent in the traditional drilling adjacent connection method caused by the lack of consistency disadvantage. Stratum pattern auto-matching method achieves automatic section line growth and can wipe out stratum pinch off, stratum absence, stratum lens phenomenon accurately. Experiments show that the geological profile constructed algorithm can accurately and efficiently reflect the stratigraphic structure of the study area, and hence it is widely used in engineering production.

The theoretical bases of oil and gas geochemical prospecting techniques are still very weak, and hence the prospecting techniques resting on these bases cannot be mature. If we want to study, develop and consummate the theory and methods of oil and gas geochemical prospecting techniques, our attitude towards the theory, the methods, the present situation, the existing problem and the new problems encountered in the development of oil and gas geochemical prospecting techniques must be practical, realistic and scientific. And we must have a clear and definite train of thought and scratch where it itches. Only in this way can our goal be attained.

The underwater magnetotelluric method is a technique performed on the water surface with the utilization of distant reference. Combined with the authors' practical experience, the present paper has described the working method of underwater magnetotelluric sounding technique (MT method) used in such waters as lakes and swamps as well as the measures taken for obtaining high-quality sounding data, and summed up some experience and understanding acquired in the work. All this provides basis for carrying out MT work in large area of waters.

Based on full collection, arrangement and integrated study of information from 11 globe geoscience transects (called GGT for short) and tens of other geophysical profiles (seismic profiles, geothermal flux profiles and magnetotelluric sounding profiles) in the Chinese continent as well as shear wave three-dimensional velocity structural data that cover the Chinese continent and neighboring regions, the present paper has described crustal structure, lithospheric structure and rheospheric structure in the Chinese continent and neighboring regiona, and made a brief discussion on the prognosis of ore resources in the Chinese continent. The lithospheric structure of China was developed on the basis of rheosphere of three different sorts of natures and hence shows obvious inheritance. The lithospheric structure is to certain extent in accord with the geotectonic unit, suggesting that the crustal structure is influenced and restricted by the lithosphere. The crust and the upper mantle both exhibit low-velocity nature, and the vertical low-vvelocity zones of seismic waves seem to be the good environment for the formation of endogenic polymetallic ore belts.

This paper introduces a novel procedure for computing source waveforms, in which the direct derivation is not necessary, and the explicit expressions for these polynomials are also not required. The computation is performed recurrently via the product of a Hermite polynomial and the Gaussian. Numerical tests reveal that the computed wavelets can model source pulse more precisely.

The calculation error in far-sector topographic correction of regional gravity data originates mainly from the errors of approximation of digital to natural terrain and the interpolation errors of random grid, and, to a lesser extend, from the errors in position. The reading error and the altitude error, however, can almost be neglected. Adiscussion on ail these errors is given in this paper with special reference to the area of Qinling Mountains.

In this paper, recent advances in the research and development of quantum magnetometers have been described together with some suggestions on further research work.

A soil gas radon survey was performed on a large scale to determine the distribution of radon in soil of Zhuhai City in Guangdong Province by means of a portable radon monitor of a semiconductor alpha spectroscopy. The survey sampled 469 sites covering an area of more than 100 km². The average of soil radon concentration in the soil depth of 0.6 m is 55.94 ± 58.54 kBq/m³ in Zhuhai urban area, whereas the concentration is 7.14±8.75, 37.64±25.92, and 151.25±196.23 kBq/m³ in the Quaternary sediments, the mixtures of sediments and weathered grain of granite, and the weathered granite in Doumen District, respectively. The high radon potential areas are located within biotitic granites and new industrial districts, as indicated by the strong correlation between the radioactivity level and geological lithology. The mean value of soil gas radon concentration in Zhuhai urban area (ZUA) is about ten times as high as that in Guangzhou, Quanzhou and Jinjing City. The results show that Zhuhai area has higher radon potential, and hence protective measures against radon should be taken into account.

The base terrace of the Qingjiang red bed basin in central Jiangxi was studied to detect stratigraphic structure and aquifer characteristics by such means as integrated application of composite profiling, induced polarization and resistivity sounding. The optimum well site and the reasonable well completion technology were chosen and, as a result, a well was drilled which could produce more than 5 000 T/d. Pumping tests show that both the quality and the quantity of the water meet the requirements. Hydrogeophysical exploration indicates that the integrated application of the electrical methods in search for water is very effective in the study area.

Over the past century, electromagnetic exploration technology has evolved from direct current resistivity and induced polarization methods to a comprehensive geophysical system. Yet, in China's new mineral exploration phase, challenges like deep-mining needs, cultural noise, and weak 3D interpretation limit traditional methods. High-power-ultrahigh-power electromagnetic technology, by boosting transmission current, combats these issues. It enhances detection depth, enables 3D exploration, and drives technological and application innovation. This paper reviews the development of high-power-ultrahigh-power electromagnetic instruments and current research. It emphasizes that technologies like true 3D full-waveform IP collection and inversion, tensor CSAMT collection and inversion, and multi-parameter joint inversion of time-and frequency-domain EM methods can strengthen deep-target detection. Future research should tackle anisotropic 3D inversion, full-domain inversion with a field source, and extracting polarization and magnetization rates under complex constraints. These advances will propel electromagnetic methods toward greater depth, precision, and intelligence, supporting China's renewed mineral exploration efforts.

Porphyry copper deposit is the most important copper deposit type in China. With the deepening of mineral exploitation, exploration geochemistry in mineral exploration has become increasingly important. Based on related literature, this paper sums up the exploration geochemical research results of porphyry copper deposits, which include such aspects as geochemical characteristics, exploration methods, anomaly evaluation and prospecting indicators. Exemplified by the Fujiawu copper deposit, this paper reports the latest advances in the study of porphyry copper deposits.

The deep mining of geological mineral information from geochemical exploration data has been a hot research topic in mathematical geology and geological big data. Despite China's abundant regional geochemical exploration data, the deep mining of geological mineral information from these data remains limited, necessitating a scientific, efficient, simple, and feasible data processing workflow and analytical methodology. This study investigated the Gaoqiao area in Huixian County, Gansu Province, China. According to the geological background and the theories of element properties and geochemical behavior, this study processed relevant element data to mine the geological mineral information in geochemical exploration data. It established preliminary mathematical models for the boundary delineation and lithofacies classification of intermediate-acid rock masses, and the boundary delineation of mafic volcanic rocks in the Gaoqiao area to scientifically guide geological mapping. It preliminarily established the target delineation model for tectonic altered rock-hosted gold deposits. The model's effectiveness was substantiated by seven newly delineated target areas with promising prospecting potential. The mineral inspection identified five ore occurrences, including four reported for anomalies related to mineralization, with two currently under provincial geological exploration. The results of this study show that by calculating and processing data based on the geochemical properties of elements, the hidden information in regional geochemical exploration data can be further mined to effectively guide and modify geological mapping, thereby enhancing mapping efficiency and quality. High-quality anomaly information can be further extracted from geochemical exploration data to effectively guide mineral prospecting in new areas.

In geoscientific field, the essential object of all the research problems is the physical world which is derived from the crust-mantle interaction and has deeply influenced globally the environment and resources. The metallogenic geochemical theory believes that the metallogenic materials are the internal factors for the metallogenic system to influence the metallogenic process, and taking metallogenic materials as the main body to study the problems of metallogenic materials and metallogenic processes is the basic meaning of the metallogenic geochemical theory, and the core subject of the studies of metallogenic rules and theories. During the mineralization process of metallogenic system, metallogenic materials formed into metallogenic series of corresponding scale. This paper outlines several scientific topics of the metallogenic geochemical studies, among which, the topic of global metallogenic system mainly studies the metallogenic processes and relations of the series of metallogenic regions, provinces and belts formed by metallogenic materials in the context of global metallogenic process; the topic of regional metallogenic system mainly studies the metallogenic processes and relations of ore field series in the context of regional metallogenic process; the topic of ore field metallogenic system mainly studies the metallogenic processes and relations of mineral deposit series in the context of ore field metallogenic process; the topic of mineral deposit metallogenic system mainly studies the metallogenic processes and relations of ore-body series in the context of mineral deposit metallogenic process. The basic research ideas concerning above mentioned studies are discussed in this paper, including the metallogenic materials' geneses and sources, migration and evolution, differentiation and concentration, as well as the zoning relations of each level's metallogenic system and series of the world during the metallogenic processes. The purpose is to summary the metallogenic rules, explore the metallogenic mechanism and guide the mineral resources exploration. Supported by modern technologies and methods of IT(information technology), modeling and AI(artificial intelligence), the metallogenic geochemical theory uses the earth system scientific ideas to study the problems of metallogenic system and metallogenic series, construct the theoretical framework for metallogenic geochemical research, and provide a theoretical basis for the mineral resources exploration, evaluation and development technics and methods.

Four basic problems in the application of Ground penetrtion-radar are discussed in this paper:(1) the wave-impedance of electromagnetic wave transmission in strata; (2) the reflectivity and transmissivity of electromagnetic field at the subsurface of strata; (3) reflective phase and propagating velocity of electromagnetic wave in strta; (4) detection depth of the Ground-penetration radar.

Liupanshan basin is a high abundance and uniform-nonuniform geochemical field in the main oil and gas basins of China, and its background tends to change from high to low from southeast (Guyuan depression) to northwest (Haiyuan depression). According to the variation characteristics of the geochemical background in this basin, the authors determined the techniques for data processing and anomaly appraisal. On the basis of index analysis, the effective geochemical index association was decided, new anomaly-extracting techniques were adopted, and the structural anomalies and composite anomalies were studied. It is found that geochemical anomalies show zoning and obvious oil-indicating characteristics.

This paper deals with the classification of piles,the multiple factors responsible for the defects and the necessity of perfection inspection.It is held that the reflected wave theoretical basis and the activation and receiving sensor constitute the crux of the inspection technique for one dimensional rods. The consistency of the frequency interpretation of reflected wave signal with the transient mechanic impedance method is illustrated with practical engineering examples.The paper also expounds the theory and grounds of applying sonic transmission method to inspect the perfection of the foundation pile,the discrimination basis and examples of the inspection,and the latest sound CT technique and its inspection achievements.

This paper has summed up the development and new application of ground-searching radar in recent years. Based on detailed analysis of the principle and system structure of ground-searching radar, the authors put forward the train of thought for improving system structure of ground-searching radar and, aimed at solving the great noise existing in ground-searching radar work and the inadaptability in transplantation of seismic data-processing technique, raise a new scheme for underground interface high-resolution imaging of ground-searching radar.

An analysis of the relationship between the elements in the earth's crust and the life elements and a study of the pathogenesis of some typical endemic diseases have revealed that unbalance of trace elements in geochemical environments is likely to result in human diseases. The factors affecting the balance of trace elements in human bodies are geochemical environments and nutrition components. The authors hold that the important measures that can guarantee the balance of trace elements in human bodies lie in the optimization and utilization of geochemical environments and the balance of bioavailable trace elements from the nutrition.

In the tentative mercurometric survey around the Qin Shi Huang Tomb, a high mercury anomalous area was detected over the tomb. This suggests that there does exist a mercury source at the depth, and that the area of the mercury anomaly might reflect the approximate position of the underground palace. The heat-release mercury study demonstrates that the soil mercury over the Qin Shi Huang Tomb is basically composed of low-temperature mercury, and that soil survey measurement is actually the reflection of low-temperature mercury. The volatile mercury in soil is consistent with the soil mercury; nevertheless, the soil mercury is more stable. Theα-cup radon measurement has yielded preliminary results in the detection of underground mercury source and the locating of subordinate funeral pits.

The main tasks of geophysical prospecting techniques in search for golddeposits are detection of or--controlling fault zonesl fracture zones and altera-tion zones, delineation of ore-bearing rock bodies and strata, determination of weak mineralization zones and search for quartz veins and other ore-bearing veins. Such traditional techniques as gravity, magnetic method, induced polari zation method and extremely low frequency electromagentic method all prove to be effective. Tests show that piezoelectric method, radio method and seis mic induced polarization method are quite promising. In addition, the study of thermoelectricity and thermoluminescent characteristics of rocks and mine rals is a new subject which deserves due consideration and will play an acti ve role in prognosis of ore resources and evaluation of ore potential.

The distinct difference of magnetic properties between magnetite ores and strongly magnetic volcanic rocks lies in the fact that magnetite ores mainly have induced magnetization, while strongly magnetic volcanic rocks are dominated by remanent magnetization. A method that could allow the remote determination of insitu magnetic properties of sources by using natural geomagnetic variations has been recommended in this paper. Comments are also made on several methods related to interpreting magnetic anomalies caused by remanent magnetization.

Based on characteristics of accompanying metallic minerals and wall lock alterations in six large-sized or gigantic gold deposits (fields), this paper analyses the physical prerequisite for indirect gold prospecting by using IPmethod. With the ore-prospecting work conducted in such gold deposits as Jiapigou of Jilin, Jiaojia of eastern Shandong, and Ailaoshan of Yunnan as examples, the author describes briefly the effectiveness of IPmethod in gold prospecting as well as the unfavorable factors affecting its application. It is pointed out that, though of some limitations, the IPmethod remains a fairly effective geophysical prospecting method in search for gold deposits under favorable geological-geophysical conditions. In order to raise the rate of conect detection in gold prospecting, the IPmethod should be actively used in such aspects as the search for concealed and blind deposits, the inspection of geochemical anomalies and the 1:50000 integrated geophysical-geochemical prospecting in metallogenic provinces.

Due to the difference of the physical and chemical properties between the normal paraffin and the isoalkane which have the same molecular weight,they are affected by the physical and chemical property of soil substrate and other external environmental factors and are hence likely to have some differentiation effects during migration,rendering their distribution in space characterized by some signature and regularity.Isomerization rate indicators φ_iC4 /φ_nC4 and φ_iC5 /φ_nC5 can expose to some extent the characteristics and regularity.With the isomerization rate indicators φ_iC4 /φ_nC4 and φ_iC5 /φ_nC5 ,we can determine organic maturity,path and direction of light hydrocarbon migration and light hydrocarbon generating environment,and study biochemical degradation of light hydrocarbon.

Since the word "the earthquake attribute" has been introduced in the geophysics,the earthquake attribute technology obtained the widespread application in the oil gas exploration development, on the consult massive pertinent datas foundation, to the earthquake attribute classification, the earthquake attribute technology history and the present situation has carried on the induction and the summary, on the condition of oil and gas exploration and the development reality ,we have discussed the earthquake attribute technology development tendency.

During the exploration of the underground medium structure, the gradiometer as well as its new deployment styles for various applications has become an important research topic of world concern. This paper describes various kinds of gradiometers based on torsion balance and difference algorithm and deals with the principle of each instrument. In addition, the absolute gradiometers based on the laser and atom interference are also described. In the last part of this paper, the design of the measurement light path is presented. The results obtained by the authors can serve as the technologic reference for developing gradiometer.