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.

China's complicated geological background and metallogenic environment have decided that the regional geochemical exploration can play an important role in the field of China's mineral resources prospecting. This is the strategic selection under special metallogenic conditions. The first round of regional geochemical exploration of China was carried out during mid-1950s. Since then, we carried out the second and third round of regional geochemical exploration. Until now, China's regional geochemical exploration has gone through a history of 70 years, and showed unique functions in fields of the exploration and development of nonferrous metals, precious metals as well as the rare minerals, rare earth and scattered minerals. According to incomplete statistics, during 36 years (1979~2015) of the second and third round of regional geochemical exploration, totally 182 different kinds of large to super-large scale deposits were discovered in China mainly by means of regional geochemical exploration. Of which, 61 deposits have nonferrous metals, 93 deposits have precious metals, 24 deposits have critical and scarce minerals, and 4 deposits have other kinds of minerals. On average, 5.06 large to super-large deposits were discovered each year, and one large to super-large deposit was discovered within every 37,000 square kilometers-Calculated on the basis that the second and third round of regional geochemical exploration covered 6.68 million square kilometers' area of China. Regional geochemical exploration has achieved outstanding results in the field of mineral prospecting, and made great contributions in terms of ensuring and promoting China's economic development. As our country's basic, public good and strategic geological work, regional geochemical exploration comes into the 21^st century marked by big data and earth system science. Based on high precision and good quality big data, guided by metallogenic geochemical theories, and supported by modern science and technology, the regional geochemical exploration will start a new period of development. In the future, we'll continue to carry out the high technical standard and high quality regional geochemical exploration, achieve our goal of complete covering the whole area of mainland China with regional geochemical exploration, and provide more strategic prospective areas for our country's mineral resources exploration. On the basis of high-precision big data, metallogenic theories and modern science and technology, we'll establish AI and IT application system, so as to push forward the exploration and utilization of deep minerals, buried deposits as well as the critical and scarce minerals which are difficult to identify, and achieve greater breakthroughs in the geological exploration of mineral resources. By using big data technics, China's regional geochemical exploration team will continuously solve the mineral resources exploration and evaluation problems, and in this process, our geochemical exploration system will be gradually integrated into our country's science and technology advancement.

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.

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.

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.

The exposed crust is the critical interface where the lithosphere interacts with the pedosphere, hydrosphere, and atmosphere. The petrogeochemical map of the exposed crust can provide essential fundamental geochemical data for investigating the distributions and cycles of elements among different spheres. However, the plotting of the large-scale petrogeochemical map of the exposed crust has been constrained by the limited data volume and mapping technology. Consequently, no such a map covering the Chinese continent is available. This study proposed an innovative mapping technology roadmap based on over 16,000 petrogeochemical data and fundamental geological information. First, the databases for petrogeochemical information, stratigraphic structure information, and spatial information of geological units were constructed. Second, the geospatial information of strata and rock masses was extracted from the basic databases. Third, the petrogeochemical information was assigned to strata and rock masses to obtain their spatial distributions and element contents. Fourth, the spatial distribution patterns of 76 elements in the exposed crust were visualized using geographical information system (GIS) technology. Additionally, this study analyzed the challenges in the mapping process, including geological information accuracy, the lack of samples for special lithologies, reliability assessment, and scope of application, finally proposing corresponding solutions. The petrogeochemical map of the exposed crust demonstrates significant application potential, providing foundational data for investigating geochemical background and rock-sediment element cycling.

The finite element method has the characteristics of strong adaptability in simulating the electromagnetic response of rugged topography and complex geological bodies. In recent years, it has been widely used in the three-dimensional (3D) forward modeling of magnetotelluric (MT) sounding. However, the finite element method also has some shortcomings in terms of computational efficiency. The large amount of calculation and long running time of the method are the main factors that lead to the lag of the practical process of the 3D MT inversion technology based on the finite element method compared with the 3D MT inversion technology based on the finite difference method. In order to improve the 3D forward speed of MT, the authors adopt the forward modeling scheme which uses the direct solver PARDISO and does not need divergence correction to solve the large-scale linear equations corresponding to the vector finite element method, and obtain the MT response of the geoelectric model under such different terrain conditions as flat and rugged topography. Under the conditions of medium-scale calculation, through the comparison between the direct solution method without divergence correction and the iterative solution method with divergence correction, the authors have detected that the direct solution method without divergence correction has advantages in calculation accuracy and calculation time, especially in the calculation. In terms of time, the ratio of the calculation speed of the direct solution and the iterative solution is raised by more than ten times.

The Fe-Cu-U mineralization in the Luzong area in Anhui Province occurs primarily within the syenite mass and along its contact zone with surrounding rocks. Effectively delineating the syenite mass using geophysical exploration methods is a scientific issue that needs to be addressed urgently for mineral exploration breakthroughs in the Luzong area. Therefore, based on 358 rock samples from scientific drilling borehole ZK01 at a burial depth of 2 012 m in the Luzong area, this study measured their petrophysical properties, including density, magnetism (magnetic susceptibility and remanent magnetization intensity), electrical properties (resistivity and polarizability), and elastic wave velocity. The results indicate that syenites manifested low density and weak magnetic characteristics, providing prerequisites for syenite identification through gravity and magnetic explorations in borehole ZK01 or similar geological conditions. The strata and syenite-monzonite masses in the borehole exhibited medium-to-high resistivity characteristics with nonsignificant differences, increasing the difficulties in electrical prospecting. The syenite-monzonite masses displayed lower compressional and shear wave velocities compared to the volcanic layer in the Zhuanqiao Formation, laying a foundation for distinguishing strata from rock masses through seismic exploration.

The present paper makes a brief description of the progress of several main electric methods which havebeen developed quite rspidly since 1980's.They include induced polarization method,frequency spectrum IPmethod,trandient electromagnetic method, controlled-source audio-frequency magnetotelluric method and GPR.

Based on recent English literature,this paper has summed up the present state and development of important gravimeters in the world,described a new type digital supergravimeter,and a new designing idea for gravimeter,viz. the application of absolute scale to the measurement of relative gravity.

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.

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.

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.

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

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.

Researches on the soil data of ecological geochemical environment in Zhanhua winter jujube growing area show that some important factors such as distribution, transform rule and modes of occurrence of beneficial and harmful elements in soils affect Zhanhua winter jujube quality and food safety. The elements such as Mo, Cd, Co, Hg, S, N and Se have the great influence on the quality of the winter jujube, and high content of Mo, Cd, Co, Hg and S, especially Hg, S and Cd, will reduce the fruit quality. Where these elements reach a certain content, they will severely reduce the fruit quality. On the contrary, the elements N and Se can improve the fruit quality of the winter jujube. It is suggested that the increase of the effective state content of Fe, K and water-extracting Se or decrease of the effective state content of B, Cu, P and N is favorable for the improvement of the winter jujube quality. The results obtained by the authors indicate clearly the way forward for fertilizer application and field management in growing winter jujube.

The Audio-frequency Magnetotelluric (AMT) sounding method is an electrical exploration technique widely used for shallow to medium-depth geological investigations. Its data quality is influenced by various factors, including cultural electromagnetic interference, electrode polarization, and grounding resistance. This study focuses on the impact of electrode polarization and grounding resistance on AMT data quality. First, the mechanisms of electrode polarization and the influence of grounding resistance on apparent resistivity and impedance phase are theoretically analyzed. Then, based on measured data, the effects of electrode polarization and grounding resistance on apparent resistivity and phase curves are investigated. Finally, a comparative analysis of 2D inversion results from field data is conducted to reveal how grounding resistance affects geological interpretation. The results indicate that electrode polarization significantly degrades data quality in the low-frequency band, though this can be mitigated through data processing techniques, while its effect on high-frequency data is negligible. Unstable grounding resistance mainly influences the high-frequency range, causing notable reductions in apparent resistivity and phase, which gradually stabilize toward the low-frequency band. Moreover, unstable grounding resistance may lead to inversion results that deviate from the true geoelectrical structure, thereby resulting in erroneous geological interpretations. The findings of this study provide important guidance for field data acquisition and processing.

The Xinfang gold deposit resides in the gold polymetallic ore concentration area in eastern Liaoning Province. Based on regional metallogenic patterns and existing exploration results, the southern part of the Yalu River fault zone, where the Xinfang gold deposit is located, shows significant potential for gold resources. As exploration progresses, more gold ore bodies are expected to be discovered in the gold deposit area. However, the lack of effective deep exploration techniques limits further exploration and exploitation in the area, failing to effectively reveal the extensions of lithological boundaries and the distributions of fault structures in the area. This study presented the first application of the wide-field electromagnetic method in the area. Based on the obtained results and geological engineering information, this study delineated the electrical layers within a depth of 3 km, determining the thickness of the Neoproterozoic cap rocks and inferring several fault zones. Combined with existing geological data, this study identified the low-resistivity anomaly zone at a depth of about 1 km as an extensional structural plane caused by ductile shearing. Overall, this study provides valuable geophysical data for establishing a geological prospecting model for eastern Liaoning Province, holding significant research value for geological and mineral exploration in the area.

Based on data available in China and abroad, the authors have made a comparative analysis and study of the water quality characteristics of rainfall runoff on roofing of different construction materials and road surface of different materials, pointed out three major factors affecting water quality of urban rainfall runoff, and dealt with the practical significance of collecting and utilizing urban rainwater.

Urban dust constitutes an important problem in urban environmental science.A review is given in this paper on the advances in the study of urban dust in various aspects both in China and abroad, such as physicochemical characteristics,spatialtemporal distribution,source,migration and transformation,bioeffect and environmental quality assessment.The future development prospects are also pointed out.It is an urgent task to study the source of urban dust at different spatial scales,the mechanism of migration and transformation and the environmental quality assessment.

The development of the gravity gradiometer is described simply in this paper, and the measuring principle and development experience of the rotating accelerometer gravity gradiometer are emphatically discussed. On the basis of researches on the existing airborne gravity gradiometer, the prospects of the airborne gravity gradiometer are also presented.

This paper deals with the problem of "acquisition footprint" in recording geometry. The effect of "acquisition footprint" on the seismic attributes and reservoir prediction was first analyzed, and then the self-adaptive filtering method was used to eliminate the "acquisition footprint", thus inhibiting the interference of "acquisition footprint" in the post-stack seismic data. Based on an analysis of the effects on seismic attributes and reservoir prediction before and after eliminating the "acquisition footprint", the authors put forward a method for eliminating acquisition footprint.

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 artificial source electromagnetic method is an important technique for deep resource exploration. The key challenge is to improve the depth and precision of detection through innovative technology. The detection mode of electromagnetic methods is evolving from far-field to near-field, and the study of near-source electromagnetic methods has become an international research frontier in recent years. Building on the recent advancements in wide-field electromagnetic methods and multi-channel transient electromagnetic methods, the short-offset transient electromagnetic method (SOTEM) has been further developed and proposed. The distinguishing features of SOTEM are its stronger signals and wider bandwidth, which are advantageous for achieving the detection requirements of greater depth and higher precision. This special issue presents eight articles covering the methods, techniques, software, and applications of SOTEM, providing strong support for the growing need for high-resolution subsurface detection.

In performing gas-prospecting work by means of neutron and density logging in strata with complicated lithology, one often meets with the trouble of multiple solutions caused by the disturbance of complicated lithology if the difference in neutron and density porosities is used alone to indicate gas zones. The logging gas-prospecting model, the calibration formula, the lower limit value of the gas zone and the criteria for verifying gas zones established in this paper have renewed the neutron and density logging gas-prospecting method and can repress the disturbance resulting from complex lithology, thus eliminating the possibility of multiple solutions. Case studies of logging gas-prospecting given in this paper demonstrate that the renewed method can indicate low porosity gas zones in strata with complicated lithology and improve the resolution, direct perceivability and piecision of this method, thus yielding better gas-prospecting results.

The all direction imagery theory for local gravity and magnetic anomaly sources in complex conditions has been formulated for the first time in recent years. In the present paper the outline of this theory is expounded, which includes the general forward series expressions for gravity and magnetic fields with complex variable of finite downward 2D-body, the all directional continuance and all directional inversion of 2D-body gravity and magnetic fields with complex variable, and so on.

This study aims to further clarify the characteristics of uranium deposits and faults in a uranium mining area in Xingyi City, thereby laying a solid foundation for subsequent drilling operations. Soil radon measurements were conducted using the FD216 environmental radon meter. The data obtained were analyzed comprehensively to determine the content and distribution of radon in the soil, delineate the anomaly halos of soil radon, and refine the properties of concealed faults. Furthermore, the metallogenic characteristics of uranium deposits were examined, combined with geological and geochemical exploration data. This study revealed a strong correlation between soil radon content and fault strike. The most significant radon anomaly zones are located in the southwest and central-northeast sides. Uranium deposits in the study area occur in fault fracture zones and are associated with strata. The uranium exploration target might be located within the fault zone in the first member of the Middle-Lower Triassic Jialingjiang Formation.

Element abundances of the continental crust and rocks cited in the past and recent literature have been based on compilations of data from various studies. This leads to uncertainties in sample representativeness and data quality. The present study is based on systematic collection of 28 253 individual rock samples over an area of 3.3 million km² in eastern China, east of eastern longitude of 105°.The sampling involves more than 800 igneous intrusive bodies and metamorphic complexes as well as more than 500 type stratigraphic sections. From the individual rock samples, 2 718 composite samples were made and analyzed for 77 elements by 15 specific methods, dominantly XRF and INAA. Analytical quality was controlled by international and national preliminary geochemical reference materials of GSR, GAu and GPt series. Synthetic results from geological, geochemical and geophysical studies were used to construct crustal constitution model, from which element abundances of the continental crust in the North China platform, the upper crust and exposed crust in eastern China, chemical composition of igneous rock in China and of sedimentary rock and metamorphic rock in eastern China were derived.

Three Thiobacillus ferrooxidans strains with strong arsenic resistance and capacity of sulfide ore decomposition, namely M1s, 1# and Malan, were used for a microbial oxidation and leaching experiment on DBF ore from Shimian County, Sichuan Province. The arsenic content and pH change in the microbial oxidation process and the optimum leaching conditions of gold were studied intensively. The change of the microbial oxidation process with time and the optimum leaching conditions of gold are given in the paper.

Based on the idea of wavelet transform,this paper puts forward a new technique for denoising log curve.First,wavelet decomposition of log curve is carried out in accordance with Mallat tower algorithm,then a nonlinear soft threshold is used to restrain and leach noise in the wavelet field,and finally the reconstructed log curve is obtained through wavelet reverse transform.The result shows that the technique is more effective than the traditional filtering method.

This paper presents new data processing and interpretation methods for the high-precision magnetic data in search for deep-buried minerals in crisis mines. Such means as the three-dimensional visualized inversion based on the numerical integral of 3D bodies, the weak signal identification by the wavelet analysis tools, the equivalent dipole layer method for the fast reduction of magnetic data from an undulated relief to a horizontal plane, and the transformation of to, all fall into this category. The performance of these new methods was illustrated in search for deep-buried minerals in the Daye iron mine, and a magnetite ore body more than 30m thick was discovered by the drilling along No.15 exploration line arranged according to the authors' interpretation in 2005. The application of these new methods shows that the adoption of these new methods is essential in the continued resources exploration for crisis mines.

The metal detection technology based on electromagnetic induction has very long application history and is the most popular technology for mine detection; besides, it plays a leading role in the mine detection domain. In this paper, the authors first introduce the basic principle of pulse induction and then propose a new metal detection technology that uses multi-periods and bipolar pulses, and finally give some experimental results. This new technology not only preserves high sensitivity of the traditional technology but also has the capacity of working under all ground conditions. It is a new development of the land mine detection technology.

Large-area hydrogen escape anomalies were detected during the soil hydrogen geochemical survey in the Zhangbei Basin, making it urgent to apply geophysical methods to understand the basement structures that generate and transport hydrogen. For this purpose, the first gravity and magnetotelluric surveys targeting natural hydrogen were conducted in the Zhangbei Basin, with 1∶50,000 gravity and magnetotelluric surveys performed within the study area. Using the collected gravity and magnetotelluric data, a large-scale gravity-magnetotelluric profile across the study area was inverted, constrained by drilling, geological, and physical property data. The study identified a "two depressions and three uplifts" structural pattern in the basin, with a total Mesozoic-Cenozoic sedimentary thickness ranging from 0.62 to 1.9 km. Four concealed faults were revealed, among which faults F₁ and F₄ can serve as migration pathways and storage channels for natural hydrogen. The inversion results indicate that the two depressions exhibited continuous and stable stratigraphic interfaces and relatively thick sandstone-mudstone assemblage layers, which provide good sealing capacity to reduce hydrogen leakage effectively. These findings on basement structures offer valuable insights for the prospect area evaluation of natural hydrogen and subsequent exploration plans in the area. They also provide a significant basis for establishing a natural hydrogen exploration technology system and selecting optimal exploration targets.

Based on results obtained in the application of shallow seismic method to the detection of karst collapse in Tangshan, this paper has studied technical lines for detecting karst collapse in concealed karst areas, put forward technological measures for improving effects of seismic exploration and seismic resolution ratios, and analysed means for geological interpretation of seismic time profiles.

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.

The Laowan gold belt is located in the eastern part of the Qinling orogenic belt, between the Nanyang and Wucheng basins. It boasts super-large gold resources hosted by moderate- to low-temperature magmatic-hydrothermal gold deposits formed during the Late Yanshanian. To explore the second exploration space and achieve new prospecting breakthroughs, this study investigated the primary halo of the No.59 ore body in the Laowan gold belt. Multiple statistical methods were employed to analyze the correlations among ore-forming elements. Accordingly, reliable geochemical indicators were identified to predict deep prospecting orientations. The results show that the primary halo of the No. 59 ore body exhibits an axial zoning sequence of Sn, Ba, As, Au, Pb, Cu, Sb, Ag, Mo, Bi, W, Hg, and Zn. The front-halo element Hg appears late in sequence, positioned after ore-forming elements Au, Ag, Pb, and Cu, suggesting the presence of blind ore bodies at depth or significant extension of the known ones to a burial depth of 650 m and above. In contrast, the rear-halo element Sn appears early in the sequence, indicating that the ore body was somewhat denuded. Correlation, cluster, and factor analyses were used to investigate the affinities between ore-forming elements and other metallic elements. Strong correlations were observed among Cu, Ag, and Au, establishing them as effective prospecting indicators within the deposit area. The cumulative index ratio of front- to rear-halo elements showed an increasing trend at a burial depth of 650 m, where a well-developed and non-closed anomaly was revealed by the F2 factor score contour. This suggests promising prospecting potential at this depth and deeper parts. Based on the comprehensive analysis, this study posits that the area at and below the burial depth of 650 m in borehole ZK3041 along the exploration line 304 is an exploration target. A prediction borehole drilled north of borehole ZK3041 saw the extension of No.59 ore body at a burial depth of about 720 m. Moreover, the assessment indicators show that the ore body still holds significant prospecting potential in the deeper part.

The Technical Symbols for Geochemical Exploration (GB/T 14839-93) is a national standard formulated in the early 1990s, including 101 symbols. The revision of this standard began in 2019 according to the following principles: (a) Inheriting the original symbols. The stability and continuity of the original standard content should be maintained as far as possible; (b) Selecting new symbols in line with professional habits. It is necessary to select symbols that are widely used in geochemical exploration and are recognized by most peers as far as possible; (c) Matching the development of geochemical exploration technologies. The revised technical symbols for geochemical exploration should cover all fields involved in the current geochemical explorations; (d) Focusing on the commonly used geochemical symbols. The commonly used geochemical symbols should be included. According to the above principles, special technical symbols for ecological geochemical surveys and evaluation were newly added, and the expanded symbols include general technical symbols for geochemical exploration and special technical symbols for mineral geochemical exploration and geochemical sample testing. A total of 173 symbols were included in the revised standard. The revised technical symbols for geochemical exploration can be divided into a general type and a special type according to their application scopes. The special geochemical symbols can be categorized into three subtypes according to their application fields, namely mineral exploration, ecological environment investigation and evaluation, and geochemical sample testing. The fields covered by the revised standard are consistent with the current application fields of geochemical exploration technologies.