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.

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.

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.

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.

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.

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 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.

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.

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.

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 study conducted a profile spectrum survey in the southern Anhui Province using a portable gamma-ray spectrometer. Based on the differences in types and quantities of natural radioactive elements present in geological bodies, this study compared the stack plots of the characteristic parameters of U, Th, and K with geologic-topographic maps to further delineate the occurrence locations of ore bodies. Additionally, this study investigated the applicability of gamma-ray spectra to the exploration of fluorite deposits and provided empirical suggestions for parameter surveys and anomaly determination. The experimental results indicate that gamma-ray energy spectroscopy applies the exploration of fluorite minerals. Notably, Th can be used as a primary indicator, exhibiting low-amplitude anomalies, which correspond well with ore bodies. Besides, this element is applicable to other surrounding rock conditions. The analysis and verification from the perspective of environmental protection revealed that the gamma-ray radiation dose rates induced by fluorite vein ore bodies are far lower than their background values and can be used as a preliminary basis for ore prospecting.

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.

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.

Based on model experiment and practical application of magnetic method for detection of underground cultural relics,this paper systematically describes the mechanism,technique,character and effects of applying magnetic method to the detection of underground cultural relics.From survey through data processing to interpretation of achievements,it probes step by step into the working method,technological features,anomaly regularity and means for inference and interpretation of magnetic archaeology.With practical examples,the paper recommends an oprable and popularizable working system,emphatically deals with the merits and prospects of magnetic archaeology,and points out the content and direction of further research work.

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

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.

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.

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.

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.

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

Given the particularity of biological samples, this study employed microwave digestion and inductively coupled plasma-optical emission spectrometry (ICP-OES) for the simultaneous determination of 12 elements in biological samples, including aluminum (Al), ferrum (Fe), magnesium (Mg), calcium (Ca), sodium (Na), potassium (K), manganese (Mn), phosphorus (P), titanium (Ti), barium (Ba), strontium (Sr), and zinc (Zn). By optimizing the pretreatment conditions of microwave digestion samples, this study selected the mixed reagent of reverse aqua regia (10 mL) and hydrogen peroxide (1 mL) as the digestion reagent, and an appropriate experimental procedure for the microwave digestion system to ensure complete decomposition of samples. Moreover, this study selected the optimal plasma excitation conditions, analytical spectral lines of elements, and background subtraction position to ensure high determination sensitivity of elements and interference-free spectral lines. This study plotted the calibration curve with the national primary reference materials for biological components as the calibration series, making the calibration series consistent with the sample matrix as much as possible. The simultaneous determination method had a total dilution multiple of 100, eliminating the interference of the matrix effect. The results show that this method had a detection limit of (0.04~4.93)×10^-6 and a relative standard deviation (RSD) of 1.41%~5.13%, showing high precision. As verified by the national primary reference materials, this method had a relative error (RE) within ±10% and determined values consistent with standard values. Therefore, this method is accurate and reliable, meeting the analysis requirements of biological samples.

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.

This paper describes the working principle of drillhole radar and recommends two working patterns:single-drillhole reflection and crosshole tomographic imaging.The technique was used to make lithologic evaluation of deep strata and detect geological anomalous bodies with obvious effects obtained.

Located in Guixi County, Jiangxi Province, the Lengshuiken?silver deposit is thelargest silver deposit in China, genetically belonging to porphyry type. Based on geological andgeoohemical characteristics of the ore deposit, thisjpaper has emphatically studied the distributionof trace elements in the ore deposit, tentatively fonnulated a geochemical prospecting model forthis ore deposit, and predicted the prospects of its development.

The geochemical data of stream sediments contain significant geological and geochemical information. In this study, R factor analysis method was applied to 1∶250 000 stream sediments data from Western Qilian Mountain. Five geochemical zones were recognized and their geological implications were discussed according to element association. The geochemical zones correspond to the tectonic units, and therefore these results can provide abundant geochemical implications for basic geology research, prediction of prospective areas and further division of Grade IV ore-forming belts.

This paper deals in detail with the basic principles and interpretation techniques forthe detection of underground line pipes with the direct detection mothod.It advances a new vectorintersection drawing method for determining positions and depths of line Pipes and givingconfidence of the detection results.Results with high. confidence can ho provided in situ.Description is also made con-cerning the instrument and equipment for line pipe detection and their application of effects.

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 tentative application of the frequency domain high density electric method to the detection of the underground palace under Qin Shi Huang's tomb turns out very effective. The work has not only proved the existence of the underground palace but also detected its location, size and buried depth. In addition, its completeness has been demonstrated.

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.

Based on 1:200 000 stream sediment survey and partial results of soil survey, the authors summed up geochemical backgrounds of As and Cd and their anomaly distribution in different media and all types of soils and bedrocks, analyzed their enrichment regularity and sources. It is concluded that the background content of As and Cd in the soil is higher than their content in the stream sediment, and is by far higher than their average content in the Earth's crust. As and Cd content is highest in lime soil and limestone, being 1.5 times of their average soil content in Yunnan Province. The background content tends to rise with the increase of pH. The high geochemical anomaly is consistent with the karst area. Seven anomaly zones of As and twelve anomaly areas of Cd were delineated, with the most outstanding anomalies all located in southeastern Yunnan where desertification is severely developed. Heavy metal anomalies of As and Cd are mainly derived from the bedrock of high background content (carbonate rock), and the main reason for its enrichment is that carbonate soil with high pH and high CEC is heavy and viscous, its organic content is high, the migration rate of As and Cd decreases and their remaining content increases, resulting in high enrichment of soil As, Cd content in some areas of Yunnan Province where carbonate rock is well developed.

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.

In this paper, the working principle of three satellites (CHAMP, GRACE and GOCE) has been described, and the important geopotential models and the newest geopotential models (EIGEN-CG01C, GGM02) have been introduced.

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.

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.

The automation of the measurement adjustment is the aim of the surveyors. Many countries have designed softwares, but the softwares have some disadvantages. This paper introduces a new way to design a measurement adjustment system on the basis of the study of the merits and shortcomings of the previous programs. The system based on VC++ and ObjectARX and AutoCAD2000 has its power roof garden. The system can calculate coordinate exactitude value and draw the net shape. The operation is very easy and hence it can serve as the surveyor's effective helper.

Denoising is an important part of magnetotelluric data processing. To enrich and develop the denoising method of magnetotelluric time series, this study introduced the LSTM network-one of the recurrent neural networks-into the square wave noise processing of the magnetotelluric time series. Different from previous studies, the measured magnetotelluric time series without human interference superimposed on simulated square wave noise were used as the input of the LSTM network, and the noise-free original time series were used as the target output of the network. After training for 1,500 epochs, the normalized cross-correlation coefficient between the time series extracted from the simulated noise signals by the network and the original time series reached 0.9718, indicating that the network has effectively learned the characteristics of the noise-free magnetotelluric time series. Finally, the denoising test results of measured square wave noise signals show that the proposed method can effectively suppress the interference of square wave noise and improve the estimation quality of impedance. This study provides a new idea for the processing of magnetotelluric time series based on deep learning.