E-mail Alert Rss
 
Office Online
News
gfff
More>>
Information
Sponsored by:
China Aero Geophysical Survey and Remote Sensing Center for Natural Resources
Edited by:
Editorial Office of Geophysical and Geochemical Exploration
Add:
29 Xueyuan Road, Beijing 100083,China
Tel: 86-010-62060192/62060193
Fax: 86-010-62060193
Email: whtbjb@sina.com
Web: http://www.wutanyuhuatan.com
Editor in Chief: XIONG ShengQing
Published by:
The Geological Publishing House (31 Xueyuan Road,Beijing 100083,China)
Printer:
Beijing Changning Printing Co. Ltd.
Distributor: Beijing Post Office
Abroad Distributor:
China International Book Trading〖DW〗Corporation
Subscription Hander:
Local Post Offices of China
Links
More>>
Published in last 1 year | In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year|

Most Downloaded in Recent Year
Please wait a minute...
For Selected: Toggle Thumbnails
Characteristics of gravity and magnetic fields in Ordos Basin and their geological significance
Bing LI, Yan-Bing SONG, Lei SHI, Qi WANG, Jiu-Ming JIANG, Jiu-Qiang JIN, De-Wen ZHOU, Ming XU, Gang-Yi XIAO, Min-Ying XIE
Geophysical and Geochemical Exploration    2019, 43 (4): 767-777.   DOI: 10.11720/wtyht.2019.1391
Abstract701)   HTML3)    PDF (3147KB)(2290)      

According to aeromagnetic and gravitational data, the boundary and range of Ordos basin were determined based on an analysis of the characteristics of gravity and magnetic fields. And on the basis of compiling depth map of the metamorphic basement and structuring zoning map, research was conducted on the basin’s basement structure, characteristics and features of depth change, structure framework, and caprock thickness. The research indicates that the metamorphic basement is composed of Proterozoic metamorphic series, and the buried depth of crystalline basement can reach 5 000 to 20 000 meters. The caprock is the layers of Ediacaran, Paleozoic, and Mesozoic. The occurrence and development of the basin are restricted by nearly NE-and NWW-trending structures, forming a pattern of four depressions and three uplifts. All the new understanding and conclusions provide a reference for further oil and gas exploration in the basin.

Table and Figures | Reference | Related Articles | Metrics
Comparison of deep learning algorithms for geochemical anomaly identification
LI Mu-Si, CHEN Li-Rong, XIE Fei, GU Lan-Ding, WU Xiao-Dong, MA Fen, YIN Zhao-Feng
Geophysical and Geochemical Exploration    2023, 47 (1): 179-189.   DOI: 10.11720/wtyht.2023.2667
Abstract225)   HTML2)    PDF (6584KB)(1204)      

There is a lack of selection bases in the geochemical anomaly identification and the reconstruction of the geochemical background conforming to the metallogenic distribution using deep learning algorithms with different network structures. Given this, based on the 1∶200 000 stream sediment data of the copper-zinc-silver metallogenic area in southwestern Fujian Province, this study extracted the combined structural characteristics, spatial distribution characteristics, and mixed characteristics of multiple elements in the samples using three unsupervised deep learning models, i.e., AE, MCAE, and FCAE. Then, these characteristics were used to reconstruct the geochemical background and simulate the metallogenic distribution. The results show that the anomaly areas delineated by the FCAE model were the most consistent with the known copper ore occurrences, followed by the MCAE and AE models. The FCAE, MCAE, and AE models had an area under the curve (AUC) score of 0.80, 0.78, and 0.61, respectively. Moreover, the FCAE and AE models were not sensitive to the change in the convolution window size. These results indicate that when deep learning algorithms are constructed for geochemical anomaly identification, the algorithms based on the extraction of spatial distribution characteristics or mixed characteristics perform well, and those based on the extraction of combined structural characteristics or mixed characteristics have a strong anti-interference ability for the noise caused by the change or inconsistency of the spatial observation scale. This study provides some effective selection bases for constructing geochemical anomaly identification models based on deep learning algorithms.

Table and Figures | Reference | Related Articles | Metrics
Review on the study of grounded-source transient electromagnetic method
ZHANG Ying-Ying
Geophysical and Geochemical Exploration    2021, 45 (4): 809-823.   DOI: 10.11720/wtyht.2021.1513
Abstract1247)   HTML653)    PDF (729KB)(1801)      

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.

Reference | Related Articles | Metrics
The advantages of AS350B3 helicopter in aerogeophysical survey in the high mountain area
Jian LI, Liang GUO, Gang-Yi XIAO, Zhi-Qiang LIU, Ming XU, Jiu-Qiang JIN, Zhi-Bo WANG, Mao-Sheng DENG, Bing LI
Geophysical and Geochemical Exploration    2018, 42 (1): 192-198.   DOI: 10.11720/wtyht.2018.1.24
Abstract672)   HTML1)    PDF (4376KB)(1219)      

The airborne geophysical exploration flying vessel which performs operation in middle and high mountain areas needs plateau adaptability.Through a comparative study of the characteristics of AS350B3 helicopter in such aspects as its taking off condition,maximum flying altitude,maximum endurance and plateau flexibility,the authors put forward the type-choosing principle and flying method of the airborne geophysical exploration flying vessel for low altitude and large scale survey.The practical surveying flying in a certain surveying area of Gansu Province has proved the feasibility of the principle and method put forward by the authors.Analysis shows that AS350B3 helicopter can meet the requirement of airborne geophysical exploration in such areas.

Table and Figures | Reference | Related Articles | Metrics
Application of integrated geophysical exploration technology in the geothermal exploration of northern Jinan
ZHANG Yi, LIU Peng-Lei, WANG Yu-Min, ZHANG Peng-Peng, ZHANG Chao, ZHANG Ning
Geophysical and Geochemical Exploration    2024, 48 (1): 58-66.   DOI: 10.11720/wtyht.2024.1141
Abstract258)   HTML10)    PDF (8896KB)(462)      

Ji'nan possesses highly abundant geothermal resources, which are hosted by Ordovician-Cambrian karst-fissured geothermal reservoirs and Neogene-Paleogene clastic pore-fissure geothermal reservoirs. The geothermal exploration in this study focuses on the Ordovician-Cambrian karst fissured geothermal reservoirs in Daqiao Town in northern Ji'nan. Through geophysical profile measurements, this study aims to identify the distributions of strata and fault structures and the burial depths of geothermal reservoirs, infer the attitudes and spatial morphologies of fault structures associated with heat control and conduction, delineate the target area for geothermal well construction, and conduct drilling verification in the favorable underground water-rich position. Building on the collected data, this study interpreted and inferred the fault structures in the study area and comparatively analyzed the water-bearing properties by employing direct-current sounding, controlled source audio magnetotellurics, and magnetotelluric survey. A geothermal exploration and production combined well was constructed in a favorable position of the geothermal target area, manifesting a completion depth of 1 532.06 m, a static-water burial depth of 13.03 m, a wellhead water temperature of 50.1 ℃, a water yield of 132.998 m3/h, and a dropdown depth of 18.27 m.

Table and Figures | Reference | Related Articles | Metrics
THE PROGRESS AND PROSPECT OF THE ELECTRICAL RESISTIVITY IMAGING SURVEY
YAN Jia-yong, MENG Gui-xiang, LV Qing-tian, ZHANG Kun, CHEN Xiang-bin
Geophysical and Geochemical Exploration    2012, 36 (4): 576-584.   DOI: 10.11720/wtyht.2012.4.13
Abstract5089)      PDF (1427KB)(2395)      
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.
Reference | Related Articles | Metrics
THE DISTRIBUTION AND LEVEL OF RADON GAS IN SOIL IN A HIGH RADIATION BACKGROUND CITY OF CHINA
WANG Nan-ping, XIAO Lei, LI Can-ping
Geophysical and Geochemical Exploration    2012, 36 (4): 646-650.   DOI: 10.11720/wtyht.2012.4.27
Abstract3861)      PDF (726KB)(2017)      
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.
Reference | Related Articles | Metrics
Prospecting for concealed skarn iron deposits using the high-precision gravity-magnetic survey method
DONG Jian, LI Xiao-Peng, FU Chao, DANG Zhi-Cai, ZHAO Xiao-Bo, ZENG Qing-Bin, HU Xue-Ping, WANG Jin-Hui
Geophysical and Geochemical Exploration    2024, 48 (1): 31-39.   DOI: 10.11720/wtyht.2024.1047
Abstract262)   HTML10)    PDF (7885KB)(432)      

The Laiwu area in central Shandong Province, situated in the eastern North China Craton, is a significant production area of skarn iron-rich ores. Its ore deposits occur primarily in the contact zone between the mining rock mass and the Middle Ordovician carbonate formation. Based on the latest areal gravity and magnetic survey results, this study thoroughly investigated the characteristics of gravity and magnetic anomalies along the Shijiaquan-Liujiamiao area in the western periphery of the mine rock mass. Then, this study delineated the deep prospecting target combining the characteristics of gravity and magnetic fields of the known iron deposits in the Laiwu area. Large-scale gravity and magnetic profiles were arranged in the favorable mineralization area. With the known boreholes as constraints, the gravity and magnetic anomalies were qualitatively and quantitatively interpreted using the 2.5D gravity-magnetic joint inversion technique. The interpretation results provide a basis for the location and depth of the borehole to be placed, which revealed a 15.8 m-thick iron-rich ore deposit, suggesting remarkable prospecting effects. This study holds critical indicative significance for further exploration of skarn iron ore deposits in this area.

Table and Figures | Reference | Related Articles | Metrics
PASSIVE SURFACE WAVES: METHODS AND APPLICATIONS
ZHAO Dong
Geophysical and Geochemical Exploration    2010, 34 (6): 759-764.  
Abstract2389)      PDF (1495KB)(1510)      

The shear wave velocity of subsurface can be estimated by analyzing the passive surface waves typically generated by cultural and natural sources. This article first introduces the passive surface waves and the processing procedure, and then utilizes the simulated passive waves to compare the FK and SPAC methods in deriving dispersion curves. It also discusses the general requirements of data acquisition and demonstrates some field examples.

Related Articles | Metrics
Advancements in research on geochemical exploration methods and technologies for mineral resources in overburden areas
SUN Yue, ZHANG Zhen-Yu, FENG Bin, YANG Shao-Ping, WANG Zhi-Feng
Geophysical and Geochemical Exploration    2023, 47 (6): 1387-1399.   DOI: 10.11720/wtyht.2023.0109
Abstract325)   HTML17)    PDF (2899KB)(455)      

Following China's planning for ore prospecting in overburden areas, China's geochemical exploration researchers have conducted extensive research on the fundamental theories, methods, and technologies of geochemical exploration for overburden areas in the past decade. They achieved significant advances mainly in two aspects: (1) the research on the migration mechanism, occurrence state, and anomaly formation mechanism of elements in overburden areas; (2) advances in methods and technologies, including geoelectrochemistry, active state of elements, geogas, separation of micro-fine-sized soil particles, soil thermomagnetic composition, and integrated gas survey, as well as numerous experimental demonstrations. These advances represent continuous progress in the research on the fundamental theories, methods, and technologies of geochemical exploration for overburden areas, providing new geochemical methods and technologies for ore prospecting breakthroughs in overburden areas.

Table and Figures | Reference | Related Articles | Metrics
A review of the research progress and application status of seismic full waveform inversion
CHEN Zi-Long, WANG Hai-Yan, GUO Hua, WANG Guang-Wen, ZHAO Yu-Lian
Geophysical and Geochemical Exploration    2023, 47 (3): 628-637.   DOI: 10.11720/wtyht.2023.1469
Abstract493)   HTML15)    PDF (3181KB)(593)      

As resource exploration deepens and becomes increasingly difficult,improving the imaging precision and the reservoir prediction accuracy under a complex tectonic setting has become a top priority of research.The full waveform inversion (FWI) method developed in recent years can be applied to complex geological structures.This method can reveal structural details in a complex geological setting using the dynamic and kinematic information in the pre-stack seismic wave field.However,this method involves many research elements such as model parameterization,building of inverse error function,data preprocessing,numerical simulation of wavelengths,and wavelet estimation.Thus,its development is bound to be a long-term gradual improvement process.The FWI method has been applied to actual observation data with the development of theory and computer technology.This study introduced the principle and processing flow of the FWI method and summarized its development history and its application status in marine and onshore seismic data,and deep seismic reflection data.Accordingly, this study presented the current application bottlenecks,data processing difficulties, and challenges of deep-crustal inversion imaging for subsequent research and application of the FWI method.

Table and Figures | Reference | Related Articles | Metrics
Geophysical characteristics and deep prospecting prediction of the Dachaigou gold deposit in the eastern Kunlun area
YU Zhong-Hong, YAN Ling-Qin, ZHANG Zhan-Xiong, LI Peng, LI Feng-Ting, FU Jia
Geophysical and Geochemical Exploration    2024, 48 (1): 40-47.   DOI: 10.11720/wtyht.2024.1126
Abstract197)   HTML6)    PDF (7232KB)(363)      

The eastern Kunlun metallogenic belt, as a significant metal metallogenic belt in China, hosts extensive orogenic gold deposits and large-scale Kunlunhe, Gouli, and Wulonggou gold concentration areas. The Dachaigou gold deposit is a large-scale gold deposit newly discovered in the Wulonggou gold field in recent years. Despite its high metallogenic potential, the western extension of its ore belt has not been defined. Hence, this study conducted induced polarization (IP) sounding and wide-field electromagnetic sounding in the deposit. The results show that the known ore belt is situated in the regional gravity anomaly gradient zone, the transition zone of positive and negative weak magnetic anomalies, the edge of IP anomalies, or the electrical gradient zone. The development zone of the regional tectonic belt resides in the large-scale IP anomaly section. The regional tectonic belt is characterized by a wide range of low-resistivity anomaly zones. The IV and III alteration zones of the known ore belt are located in the opening position of the low-resistivity anomaly zone and the shallow electrical anomaly gradient zone, respectively. Based on the above understanding and the electromagnetic anomaly change patterns of several parallel profiles in the western extension segment, it was inferred that the regional ore-controlling structure extends steadily in the W-NWW direction, forming a favorable prospecting space in the western extension segment of the deposit. The results of deep geophysical exploration in the Dachaigou deposit indicate that geophysical methods manifest significant advantages in deep geological prospecting research, providing successful experience for deep prospecting in the eastern Kunlun gold deposit area.

Table and Figures | Reference | Related Articles | Metrics
APPLICATION OF SURFER SOFTWARE IN GEOPHYSICAL EXPLORATION
ZHU Qing-jun, LI Feng-zhe
Geophysical and Geochemical Exploration    2007, 31 (3): 250-251,255.  
Abstract2411)      PDF (660KB)(1358)      

This article presents the plotting process of plane isoline map with hypsography, introduces the improtant effect of differential operator in geophysical exploration, at the same time , gives the real cases.

Reference | Related Articles | Metrics
Forward modeling on the seasonal frozen soil region detection by ground penetrating radar
Er-Qiao SONG, Si-Xin LIU, Rong-Qin HE, Jia-Qi CAI, Kun LUO
Geophysical and Geochemical Exploration    2018, 42 (5): 962-969.   DOI: 10.11720/wtyht.2018.1458
Abstract595)   HTML3)    PDF (4554KB)(894)      

With the change of season, the physical parameters in the process of freezing and thawing in active layer of seasonal frozen soil region change significantly. Taking the seasonal frozen soil in Northeast China as an example, the authors used the Gaussian distribution rough surfaces to simulate the rough freezing and melting layers, established the random media model which can accurately described heterogeneity of the active layers, and carried out forward modeling. The results show that the depth of freezing and melting layers changes with the seasons, together with the change of permittivity and conductivity. The scattered waves in radar profile are very developed because of the heterogeneous active layer and the undulating freezing and melting layers. With the change of time, the greater the fluctuation of the melting layer, the stronger the scattered wave energy in the radar profile, the harder the reflection of the melting and the freezing layers. At the same time, it is proved that the application of GPR to monitor the seasonal variation, frozen depth and melting depth of seasonal frozen soil is a practical method.

Table and Figures | Reference | Related Articles | Metrics
The application of geological radar to urban geological pipeline detection in the loess area
HAN Jia-Ming, ZHONG Xin, JING Shuai, LIU Ping
Geophysical and Geochemical Exploration    2020, 44 (6): 1476-1481.   DOI: 10.11720/wtyht.2020.0015
Abstract829)   HTML4)    PDF (3039KB)(813)      

Geological and underground pipeline detection was carried out in several urban metro exit areas in the loess area by using ground penetrating radar (GPR). The distribution of soil layer in the loess area was emphatically studied. The GPR images of PVC pipelines and metal pipelines in the loess area under the conditions of holes, seepage and soil collapse were analyzed, and the respective GPR scans of underground pipelines in the loess area were summarized. By describing the characteristics of the images, the authors summarized the general analysis methods and rules of applying GPR to detecting urban geological stratification and pipeline radar images in the loess area, and used the image laws of "black-white-black" and "white-black-white" to analyze the GPR images, which provides a good guidance for subsequent engineering construction.

Table and Figures | Reference | Related Articles | Metrics
Summary of development and key issues of offshore OBC-OBN technology
Bin LI, Qi-Kun FENG, Yi-Biao ZHANG, Fu-Qiang HUANG
Geophysical and Geochemical Exploration    2019, 43 (6): 1277-1284.   DOI: 10.11720/wtyht.2019.0370
Abstract1479)   HTML233)    PDF (5024KB)(1626)      

In recent years,offshore OBC and OBN technology has achieved rapid development.Whether it is OBC acquisition or OBN acquisition,many new equipment and methods were developed.Based on the latest research results and published papers,this paper summarizes the development history and research status of offshore OBC and OBN technology,and summarizes the technology and equipment for offshore four-component seismic exploration and acquisition,as well as processing and interpretation techniques.It is considered that the seabed multi-component seismic is the development trend of marine seismic,because it has the advantages of multi-component data, wide azimuth and wide frequency compared with the marine tow streamer.But the processing of data and conversion wave need to be researched.Now offshore oil and gas exploration is in the stage of complex structures and lithologic reservoirs,as the cost of submarine seismic decreases and the processing technology advances, it will be get more applications.

Table and Figures | Reference | Related Articles | Metrics
Differences in the characteristics of geomagnetic diurnal variation in different periods and their influence on correction of geomagnetic diurnal variation
LI Xing-Kang, FU Yong-Tao, ZHOU Zhang-Guo, YANG An
Geophysical and Geochemical Exploration    2023, 47 (1): 135-145.   DOI: 10.11720/wtyht.2023.1138
Abstract198)   HTML4)    PDF (7178KB)(551)      

The phase difference (i.e., time difference) and amplitude difference between the geomagnetic data of the offshore work area and the geomagnetic diurnal variation data of the remote stations are still challenges to the precision of the marine magnetic survey network. Based on the stations on both sides of the East China Sea and three stations in Europe at higher latitudes, this study analyzed and made statistics on the numerical differences in morphological characteristics, phase differences, and amplitude differences of the diurnal variation curves during the daytime, nighttime, and the periods of intense magnetic disturbance. The results are as follows. During the daytime, the phase difference between the stations is constantly changing, resulting in a large amplitude difference around noon. During the nighttime, the data of the stations have consistent phases, and the amplitude difference is mostly less than 4 nT. During strong magnetic disturbance activities such as magnetic storms, the phases of the stations are consistent, and the amplitude difference is even smaller than that during quiet days. According to the survey data of the ocean, the absolute value of the difference at intersections between the survey lines during magnetic storms and quiet days is less than 3.2 nT. The variation characteristics of the phase difference and amplitude difference of the geomagnetic diurnal data between stations facilitate the diurnal variation correction of the marine geomagnetic data.

Table and Figures | Reference | Related Articles | Metrics
Gravity field characteristics and boundaries of geotectonic units on the northeastern margin of the Linyi uplift, Shandong Province
WANG Run-Sheng, WU Bin, ZHANG Hai-Rui, YU Jia-Bin, DONG Yan-Long, GUO Guo-Qiang, KANG Yi-Ming
Geophysical and Geochemical Exploration    2023, 47 (2): 279-289.   DOI: 10.11720/wtyht.2023.1144
Abstract1132)   HTML26)    PDF (9602KB)(796)      

The northeastern margin of the Linyi uplift is located at the eastern end of the Luxi Block and immediately adjacent to the Yishu fault in the east. The main structural framework of the study area is controlled by the NE-trending Tangwu-Gegou fault and the NW-trending Mengshan fault. Covered by the Cenozoic sediments, the boundaries of main tectonic units in the study area are almost all concealed, and it is necessary to further investigate the change in the strike of the eastern end of the Mengshan fault as well as the distribution of the angular unconformity along the northern boundary of the Linyi uplift. Using the latest 1:50,000 high-precision gravity data, this study mainly investigated the positions and intersection relationships of the boundaries of tectonic units based on the qualitative analysis of gravity field, the interpretation of multiple gravity potential field conversion, and the division scheme of geotectonic units in Shandong Province. The analysis results are as follows. The Mengshan fault at the junction of the Mengshan uplift and the Pingyi sag transitions from the NW trending to nearly-EW trending in the east of Bancheng Town, significantly cuts the NE-trending Tangwu-Gegou fault, and shows a NW-trending turn to the east again. The angular unconformity at the junction of the Linyi uplift and the Pingyi sag neither ends in the Mengshan fault in the north nor turns southward but extends to the Tangwu-Gegou fault in the east. This unconformity also controls the southern boundary of the Pingyi sag, making the NW-trending banded gravity anomalies of the sag turn eastward. Consequently, the boot-shaped low-value gravity anomalies were formed in the study area. Based on the high-precision gravity boundary identification, this study determined the fault system and tectonic division of the northeastern margin of the Linyi uplift, providing high-precision gravity data for the basic geological study in the study area and laying a good foundation for further mineral geological survey.

Table and Figures | Reference | Related Articles | Metrics
A TENTATIVE DISCUSSION ON INTERFERENCE FACTORS AND IMAGE CHARACTERISTICS IN THE APPLICATION OF GEOLOGICAL RADAR TO ENGINEERING EXPLORATION
LAN Zhang-song, Zhang-Hu-sheng, ZhANG Yan-sun, SUN Wen-cai
Geophysical and Geochemical Exploration    2000, 24 (5): 387-390.  
Abstract1982)      PDF (481KB)(1585)      

This paper describes in brief some interference factors in the application of geological radar to engineering exploration, makes an analysis of image characteristics of interference factors and causes for their formation,suggests some measures for suppressing these interference factors, and provides some basic data for the interpretation of geological radar data in engineering exploration.

Reference | Related Articles | Metrics
Advances in research on the distributed optical fiber acoustic sensing system in the field of geophysical exploration
ZHOU Shao-Yu, BAO Qian-Zong, SHI Wei
Geophysical and Geochemical Exploration    2024, 48 (2): 411-427.   DOI: 10.11720/wtyht.2024.1304
Abstract288)   HTML5)    PDF (7793KB)(313)      

Distributed acoustic sensing (DAS) technology, one of the most advanced sound field detection technologies, can achieve distributed, long-distance, and high-precision real-time detection of the ambient vibration and sound field information interacting with optical fiber. The optical fiber exploration system of the DAS technology solves the problems of high cost and deployment difficulty of conventional geophones in complex geological environments. In recent years, the DAS technology has experienced rapid development, especially in monitoring application scenarios that require long-term and large-scale deployment. However, its systematic understanding is insufficient due to divergent research results. To further understand the research advances of the DAS technology in geophysical exploration for more effective subsequent research, this study systematically classified and summarized the development history of the DAS technology and its recent research results in geophysical exploration based on the oil and gas, marine, and environmental engineering application scenarios through literature research. This study focused on the development process of the DAS technology in different directions, the research advances in data processing, and relevant literature with specific results. Finally, this study generalized the development trend and urgent problems of the DAS acquisition system, analyzing the DAS development prospect.

Table and Figures | Reference | Related Articles | Metrics
A review of thirty years of airborne geophysical surveys in the Qiangtang Basin and future prospect
ZHOU Dao-Qing, XIONG Sheng-Qing, WANG Bao-Di, CAO Bao-Bao, GUO Zhi-Hong, HU Yue, ZHENG Yu-Zhou, ZHAO Rui, WEI Yan-Yan, XIAO Meng-Chu, HU Xia-Wei, YAN Qiao-Juan
Geophysical and Geochemical Exploration    2024, 48 (2): 287-295.   DOI: 10.11720/wtyht.2024.1413
Abstract240)   HTML15)    PDF (7354KB)(311)      

Airborne geophysical surveys, characteristic of being green, economical, efficient, and subjected to less influence by surface factors, serve as the one of most effective means of basic surveys and scientific research on the Qinghai-Tibet Plateau. This study reviewed the progress in the airborne geophysical surveys in the Qiangtang Basin of the Qinghai-Tibet Plateau in the past thirty years, systematically summarizing the progress and geological interpretation results of comprehensive airborne geophysical surveys in the basin. Furthermore, this study presented research progress and understanding of major basic geological issues of the basin, such as the basin's boundaries, central uplift zone, basement properties, deep structures, and cover characteristics, as well as the identification of favorable structural areas for oil and gas exploration. Finally, based on an analysis of the developmental trends of airborne geophysical surveys in the Qiangtang Basin, this study proposed opinions and suggestions for key research directions in the future.

Table and Figures | Reference | Related Articles | Metrics
Processing of the seismic Rayleigh wave data of coalfields based on the improved phase-shift method
LI Xin-Xin, LI Jiang, LIU Jun, SHEN Hong-Yan
Geophysical and Geochemical Exploration    2022, 46 (6): 1470-1476.   DOI: 10.11720/wtyht.2022.0078
Abstract206)   HTML3)    PDF (3848KB)(425)      

The phase-shift method is commonly used to extract the Rayleigh wave dispersion curves.However,in the case of a complex wave field,the dispersion spectra calculated using the phase-shift method have a low resolution of Rayleigh wave dispersion energy,reducing the accuracy of the dispersion curves.This study improved the phase-shift method by obtaining the power exponent of the amplitude of each point on the dispersion spectra to improve the convergence and focusing properties of the dispersion energy.The improved phase-shift method was used to process the simulated data of the theoretical stratigraphic model and the actual seismic data of a coalfield in a certain study area.The processing results were compared with the dispersion spectra generated using the conventional phase-shift method.Moreover,the inversion based on dispersion curves of the actual data was conducted to generate a two-dimensional (2D) S-wave velocity section of the study area.As revealed by the study results,the improved phase-shift method can enhance the signal-to-noise ratio of the Rayleigh wave signals in the frequency-velocity domain and improve the resolution of the dispersion energy spectra and the accuracy of the dispersion curves.

Table and Figures | Reference | Related Articles | Metrics
A GENERALIZED DESCRIPTION OF THE DEVELOPMENT OF ELECTRIC EXPLORATION METHODS
Li Jinming
Geophysical and Geochemical Exploration    1996, 20 (4): 250-258,249.  
Abstract3910)      PDF (659KB)(1839)      

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.

Reference | Related Articles | Metrics
Development of the NB-IoT-based measurement and control software for broadband SIP response testers for rock and ore specimens
HOU Sheng-Lan, CHEN Ru-Jun, WANG Zi-Hui, LIU Zhi-Tong, LIU Jin
Geophysical and Geochemical Exploration    2022, 46 (6): 1463-1469.   DOI: 10.11720/wtyht.2022.1542
Abstract190)   HTML0)    PDF (2189KB)(416)      

Spectral induced polarization (SIP) response testers for rock and ore specimens determine the SIP response differences between ore bodies and host rocks by measuring the SIP characteristics of rock and ore specimens, thus providing a basis for ore prospecting. They are widely used in geophysical exploration. However, the existing SIP response testers have shortcomings in terms of bandwidth, intelligence, portability, and power consumption. Given this, this study developed a piece of measurement and control software for SIP response testers based on the Internet of Things (IoT) techniques including NB-IoT, Bluetooth, and Wifi, realizing the functions such as near-field communication, cloud communication, data visualization, and data processing. The test results verify that the software can achieve the desired effect owing to its easy operation, stable running, and friendly man-machine interaction.

Table and Figures | Reference | Related Articles | Metrics
PRESENT STATE AND REVIVAL OF GRAVITY GRADIOMETRY
Zeng Hualin
Geophysical and Geochemical Exploration    1999, 23 (1): 1-6.  
Abstract2276)      PDF (474KB)(2083)      

In this paper,a historical review of the gravity gradiometry is given, the application of this technique to oil exploration and some other fields is described,and its development in future is predicted.

Reference | Related Articles | Metrics
Improvement in active-source surface wave acquisition device and its application in subway construction exploration
QIN Chang-Chun, WANG Guo-Shun, LI Jing
Geophysical and Geochemical Exploration    2024, 48 (1): 264-271.   DOI: 10.11720/wtyht.2024.1132
Abstract101)   HTML1)    PDF (8905KB)(300)      

With the rapid development of cities and the accelerated construction of subway tunnels,there is an urgent demand for the detection of unfavorable geological bodies ahead of tunnel excavation.It is difficult for traditional electromagnetic methods to yield excellent detection results in an urban environment with high electromagnetic interference.Active-source surface wave exploration has gained increasing popularity in shallow superficial exploration and engineering geophysical prospecting in cities due to its strong anti-interference,convenient acquisition devices,and low construction cost.However,the traditional active-source reflection seismic method uses only a heavy hammer with limited excitation energy as a seismic source,and the collected signals are prone to be disturbed by urban activities.Meanwhile,the asphalt or cement pavement in urban areas is unfavorable for the placement of geophones and the excitation of seismic signals from a hammer.Given these,this study improved the geophones and seismic source devices at low costs,obtaining a more efficient and user-friendly surface wave acquisition device.As confirmed by practical engineering exploration,the improved device can collect surface-wave signals with strong energy and high signal-to-noise ratios,resulting in high-quality data,desirable inversion and imaging results,and high consistency between the geological defects and actual geological conditions.The improved acquisition device can be extensively promoted and referenced in active-source surface wave exploration in cities.

Table and Figures | Reference | Related Articles | Metrics
Characteristics and influencing factors of Se content in the farmland system in Bailang County, Tibet, China
Duo-Ji-Wei-Se , Ci-Ren-Wang-Dui , Ni-Ma-Luo-Zhuo , ZHOU Peng, Ni-Ma-Ci-Ren
Geophysical and Geochemical Exploration    2023, 47 (4): 1118-1126.   DOI: 10.11720/wtyht.2023.1201
Abstract103)   HTML1)    PDF (2651KB)(382)      

The development of Se-rich land has been carried out in many regions of China, achieving remarkable results. However, no Se-rich land or crop has been reported in Tibet. This study analyzed the characteristics and influencing factors of the Se content in the soils and crops of the key arable land areas in Bailang County, Tibet, aiming to lend support to the development and utilization of Se-rich land in the Qinghai-Tibet Plateau. The results are as follows: The soils in the study area have a Se content of (0.05~0.76)×10-6, which is higher than the background value of soils in Tibet (0.15 ×10-6); 76.83% of the land in the study area has sufficient Se, and land in the study area with a Se content of greater than 0.3 ×10-6 covers an area of 45.43 km2, as determined according to the standard threshold of Se content in alkaline soils (w(Se)≥0.3 ×10-6). Further investigation shows that highland barley seeds have a Se content of (0.017~0.17)×10-6 (average: 0.063 ×10-6) and rapeseeds have a Se content of (0.043~0.14)×10-6 (average: 0.078 ×10-6) in the distribution area of Se-rich soils. As indicated by the root soil results of the zones with Se-rich soils, the Nieru Group controls the source of Se in soils, and Se and effective Se content in the soils are significantly positively correlated with N, P, alkali-hydrolyzable nitrogen, and rapid available phosphorus but is significantly negatively correlated with pH. These results indicate that the behavior of Se is significantly affected by a large number of nutrient elements in the soils and pH. Overall, the distribution areas of Se-rich soils in Bailang County have high soil environmental quality, crops with a high Se content, and great potential for the development of Se-rich plateau characteristic agricultural products.

Table and Figures | Reference | Related Articles | Metrics
Research on the application of the integrated gravity-magnetic-radioactive geophysical exploration method in the exploration of rare earth deposit in Weishan, western Shandong
LAN Jun, LI Zhao-Ling, ZHANG Peng, LI Zhi-Min, LI De-Jian, XING Nan, SUN Li, YANG Yun-Tao, XU Hong-Yan, WANG Jian, WANG Qiao-Yun
Geophysical and Geochemical Exploration    2023, 47 (6): 1417-1424.   DOI: 10.11720/wtyht.2023.0189
Abstract203)   HTML8)    PDF (4793KB)(347)      

Since the periphery of the Xishan rare earth deposit in Weishan County, western Shandong is mostly covered by the Quaternary strata, single geophysical exploration methods are ineffective in searching for rare earth elements in this area. To establish a geological-geophysical prospecting model for deep rare earth prospecting in this area, a combination of exploration techniques and methods suitable for the deep exploration of rare earth deposits in this area were selected through multiple geophysical exploration technology experiments on the known geological profiles. The distribution range of the underground Mesozoic Xishan alkaline complex was roughly determined through gravity survey and high-precision magnetic survey. The ore body outcrop was delineated through ground-based gamma spectrometry, and the deep ore body characteristics were revealed through drilling. Finally, this study developed an integrated geophysical exploration method including gravity-magnetic joint delineation of rock masses, radioactive positioning for ore body outcrops, and deep drilling. By using this exploration model, one super-large rare earth deposit was discovered in this area, providing a reference for the exploration of rare earth deposits in the surrounding area.

Table and Figures | Reference | Related Articles | Metrics
Practices and future research directions of geophysical exploration for normal-pressure shale gas in complex structural areas,southeastern Chongqing
HE Xi-Peng, LIU Ming, XUE Ye, LI Yan-Jing, HE Gui-Song, MENG Qing-Li, ZHANG Yong, LIU Hao-Juan, LAN Jia-Da, YANG Fan
Geophysical and Geochemical Exploration    2024, 48 (2): 314-326.   DOI: 10.11720/wtyht.2024.1202
Abstract129)   HTML7)    PDF (7986KB)(297)      

Southern China boasts great potential for normal-pressure shale gas resources,with distribution areas primarily including the peripheral complex structural areas and the extrabasinal fold belts of the Sichuan Basin.These areas exhibit intricate surface and subsurface geological conditions,leading to poor seismic acquisition quality,low imaging accuracy,and unclear varying patterns of sweet spot parameters.This study systematically summarized the research achievements and technical advances in the seismic acquisition,image processing,and reservoir prediction for normal-pressure shale gas in southeastern Chongqing,including:①The development of variable-density 3D observation system design technique and the seismic excitation and reception technique for complex mountains with limestone surfaces,ensuring sufficient sampling of the reflected wave field in complex subsurface structures and improving data quality and construction efficiency;②The optimization of prestack seismic preprocessing technique for complex mountains,imaging techniques for complex structures in basin-margin transition zones, and imaging techniques for synclinal structures in extrabasinal fold belts,achieving resulting profiles with high signal-to-noise ratios,wide effective frequency bands,and high structural imaging accuracy;③The quantitative prediction of the thickness,formation pressure coefficient,and brittleness of high-quality shales based on research on petrophysical characteristics;the quantitative prediction of the organic carbon content,gas content,and porosity of shales based on statistical petrophysics;the quantitative prediction of fractures formed due to the superimposed effect of multi-stage structural modifications based on the paleo-stress field evolution revealed using the finite element simulation technique;and the ascertainment of the distribution patterns of the current in-situ stress field using the current stress field prediction technique developed using the combined spring model.The above breakthroughs have effectively guided the sweet spot prediction,exploration,and production of normal-pressure shale gas,providing a basis for the discovery of the Nanchuan normal-pressure shale gas field.Subsequent research should focus on more scientific and reasonable seismic acquisition techniques based on seismic reception using 5G wireless nodes,high-precision automatic image processing technologies for high-steep structures in complex mountains,and integrated geology-engineering-economy seismic evaluation methods for sweet spots.

Table and Figures | Reference | Related Articles | Metrics
Design and implementation of key technologies for real-time three-dimensional ground-penetrating radar
YIN Da, XIN Guo-Liang, SUN Xue-Chao, ZHANG You-Yuan, ZHANG Qi-Dao
Geophysical and Geochemical Exploration    2024, 48 (1): 194-200.   DOI: 10.11720/wtyht.2024.1030
Abstract180)   HTML0)    PDF (3013KB)(296)      

To improve the detection level of municipal roads for rapid and effective municipal road collapse warning and rapid search for municipal pipe network distribution, the 22nd Research Institute of China Electronics Technology Group Corporation designed and developed real-time three-dimensional ground-penetrating radar (3D GPR). With the real-time 3D GPR, which is based on the architecture of field programmable gate array and digital signal processor (FPGA&DSP), the institute achieved the design and implementation of several key technologies for the multi-channel high-speed acquisition system, enriching the road detection techniques and methods. The real-time 3D GPR enables high-speed acquisition of ten-channel radar data using the horizontally polarized antennae equipped with five transmitters and six receivers. The channels can be switched using high-speed switches, which operate in an interactive interpolation manner. The 3D GPR allows for up to 32 channels and detection speeds of above 60 km/h (channel interval: 2 cm). This is attributed to the switching of the antenna array using switches. The optimum antenna polarization design was verified by the comparison of experimental data from cavity- and metal-plate-based experimental sites. As a result, the optimal antenna scheme was determined. The measured results show that, compared to general LTD-2600 radar, the real-time 3D GPR boasts a higher acquisition speed and higher performance in terms of amplitude and phase, conducive to the improvement of road disaster detection technologies. Therefore, there is high market demand for the real-time 3D GPR.

Table and Figures | Reference | Related Articles | Metrics
Environmental quality characteristics of soil and health risk assessment of crops of farmlands in the southern suburb of Baotou
Bao Feng-Qin, Cheng Hang-Xin, Yong Sheng, Zhou Li-Jun, Yang Yu-Liang
Geophysical and Geochemical Exploration    2023, 47 (3): 816-825.   DOI: 10.11720/wtyht.2023.1159
Abstract177)   HTML739)    PDF (2468KB)(453)      

To investigate and assess the characteristics of cadmium, lead, and zinc in the soil and crops in the farmland around the old industrial area in the south of Baotou City, this study analyzed and tested the heavy metal content in soil, crop root soil, and seeds, assess the pollution according to relevant standards, and conducted the risk assessment and source analysis of heavy metals using the pollution index, the bioconcentration factor, and human health risk index. The results are as follows:Regarding the soil environmental quality, the soils in the study area are dominated by clean soils, with the polluted soils distributed primarily on both sides of the old sewage canals.The sites of over-limit root soils are also primarily distributed around the old sewage canals.Among the heavy metal morphologies, carbonate-bound, Fe-Mn-bound, and residue heavy metals account for relatively high proportions, while exchangeable heavy metals (water-soluble and ion-exchange) account for relatively low proportions. Most of the seed samples exhibited normal and low enrichment of heavy metals. Compared with other crops, sunflower seeds showed super adsorptivity of cadmium, lead, and zinc, posing significant non-carcinogenic and carcinogenic health risks to children and adults.

Table and Figures | Reference | Related Articles | Metrics
Exploring electromagnetic noise suppression technologies for magnetotelluric sounding in high-interference ore districts
HAO She-Feng, TIAN Shao-Bing, MEI Rong, PENG Rong-Hua, LI Zhao-Ling
Geophysical and Geochemical Exploration    2024, 48 (1): 162-174.   DOI: 10.11720/wtyht.2024.1140
Abstract124)   HTML3)    PDF (9636KB)(292)      

Magnetotelluric sounding (MT) has been extensively applied in mineral resource exploration. However, strong anthropogenic electromagnetic interference severely constrains the acquisition of high-quality original MT data. This study provided a detailed summary of the common types of electromagnetic noise sources in China and analyzed the characteristics of electromagnetic noise they produced. By comparing the methods for MT electromagnetic noise reduction at home and abroad, this study developed a rapid and effective construction and processing technology for MT data denoising in high-interference ore districts based on actual production demands. The results indicate that Robust processing, remote reference technique, and manual selection are effective and necessary in enhancing MT data quality. Besides, theoretical calculations suggest that the distance between the remote reference stations should be set at 3.56-fold skin depth or above, as verified by the MT experiments in the ore district of the Hongze salt basin, Jiangsu Province.

Table and Figures | Reference | Related Articles | Metrics
A review of seismic tomography methods
Chang LIU, Zhen-Chun LI, Ying-Ming QU, Yi-Peng XU, Wei-Jie ZHAO
Geophysical and Geochemical Exploration    2020, 44 (2): 227-234.   DOI: 10.11720/wtyht.2020.1243
Abstract1476)   HTML950)    PDF (550KB)(1601)      

As a method for effectively reducing the velocity model of the subsurface media,seismic tomography provides a reliable initial velocity model for full waveform inversion.The finite frequency characteristics of seismic wave propagation are realized from primitive ray toe to phase shift travel time tomography and instantaneous travel time tomography.From the acoustic wave equation to the elastic wave equation and from the isotropic medium to the VTI,TTI media,the simulation of the real underground medium is realized.The morbidity of mitigating tomographic inversion has also been a research hotspot.The commonly used methods have regularization,and the sensitive nucleus of Gaussian beam tomography has replaced the traditional ray-sensitive nucleus.Furthermore,in order to avoid the dependence of the accuracy of the imaging results on the true depth of the reflection bits on the common imaging gather,the angular domain double differential reflection tomography can converge stably and efficiently to the accurate migration velocity model.At present,tomography is gradually transitional to anisotropic media,data used are transitional from VSP to WVSP,and a single waveform is developed into multiple waveforms combined inversion.However,problems related to resolution and computational efficiency still require attention.

Reference | Related Articles | Metrics
A TENTATIVE DISCUSSION ON THE RESOLUTION OF THE GROUND-PENETRATING RADAR
YUAN Ming-de
Geophysical and Geochemical Exploration    2003, 27 (1): 28-32.  
Abstract2547)      PDF (512KB)(2103)      

In the light of the pulse width of the radar wave, this paper deals with the difference and the relationship between the vertical resolution and the transverse resolution of the ground-penetrating radar, indicates the influence of the noise upon the resolution and, with practical examples, points out that the digital handling of the signal can greatly improve the resolution of the radar.

Reference | Related Articles | Metrics

THE APPLICATION OF THE MAGNETIC AZIMUTH ANOMALY METHODTO DETERMINING THE LOCATION OF A MAGNETIC BODY
YANG Kun-Biao, TAO De-Yi, FAN Xin-Sheng
Geophysical and Geochemical Exploration    2010, 34 (6): 717-721.  
Abstract1984)      PDF (1220KB)(1062)      

With the domestic borehole magnetometer, the authors calculated magnetic azimuth in the nonmagnetic interference hole and introduced the concept of Δβ, which is called magnetic azimuth anomaly. The relationship between the symbol of Δβ and the direction of ΔH was clarified, and the relationship between the figure of Δβ and the magnetic body position was obtained. It is thus held that we can use Δβ as an auxiliary parameter in the calculation of magnetic source position.

Related Articles | Metrics
Application of high-density electrical resistivity tomography and audio magnetotellurics for groundwater exploration in the karst area in southwestern China
XIA Shi-Bin, LIAO Guo-Zhong, DENG Guo-Shi, YANG Jian, LI Fu
Geophysical and Geochemical Exploration    2024, 48 (3): 651-659.   DOI: 10.11720/wtyht.2024.1237
Abstract187)   HTML7)    PDF (5894KB)(288)      

Huize County of Yunnan Province is situated in the karst area in southwestern China, where karst groundwater is its primary water source. To conquer local difficulties in drinking water, this study constructed a conceptual model of groundwater occurrence by fully investigating the hydrogeological conditions of the Huize area. Moreover, this study evaluated the applicability and optimal combination of geophysical methods based on the measurement results of petrophysical properties. According to the actual local needs, this study deployed a comprehensive profile combining high-density electrical resistivity tomography (HDERT) and audio magnetotellurics (AMT) in Tuogu Village, Huize County. The groundwater enrichment site was delineated relying on resistivity anomalies, effectively guiding the layout of boreholes. The boreholes achieved the maximum single-borehole water yield of 20.76 m3/d, thus effectively alleviating the local drinking water problem. The HDERT-AMT combined exploration method proves to be optimal for prospecting for groundwater in carbonate rock areas. HDERT can accurately characterize weathered layer thicknesses, bedrock boundaries, fissure evolutionary degrees, and water-bearing properties of strata, constraining groundwater recharge channels, thus counteracting AMT's defects for identification of near-surface stratigraphic structures. AMT can accurately reflect the spatial structures of fracture zones and the macrostructures of strata, limiting the boundary conditions (aquicludes) of water-bearing structures, thus making up for the defects of insufficient detection depths of HDERT in high-resistivity stratigraphic regions. HDERT and AMT, which are complementary to each other in terms of accuracy and depth, can be applied to identify and constrain the spatial occurrence conditions of groundwater migration, storage, and enrichment.

Table and Figures | Reference | Related Articles | Metrics
Application of comprehensive geophysical prospecting in exploration of the Duhu copper deposit in Xinxing County
HE Jun-Fei
Geophysical and Geochemical Exploration    2024, 48 (2): 375-381.   DOI: 10.11720/wtyht.2024.1101
Abstract222)   HTML11)    PDF (5778KB)(287)      

Since individual geophysical exploration methods suffer the multiplicity of solutions, comprehensive geophysical prospecting has been extensively applied in deep ore prospecting presently. This study conducted the geological exploration of the Duhu porphyry copper deposit in Xinxing County using multiple geophysical methods such as high-precision magnetic survey and controlled source audio-frequency magnetotellurics (CSAMT). It was inferred that the CSAMT-derived medium-low resistivity anomalies and the low-gentle anomalies derived from the high-precision magnetic survey serve as significant prospecting indicators. Satisfactory results were achieved in follow-up verification of the anomalies. Specifically, copper, molybdenum, silver, and gold mineralized bodies with a cumulative thickness of 178.2 m were identified in a 1 000 m deep borehole, with the highest copper grade of 1.45%. The application of comprehensive geophysical prospecting holds great significance in guiding the exploration of porphyry copper deposits in western Guangdong.

Table and Figures | Reference | Related Articles | Metrics
Hydrogeochemical characteristics of deep geothermal fluids in the Binhai New Area, Tianjin City
SHI Xiao-Jin, LI Yuan-Yuan, HUANG Xian-Long
Geophysical and Geochemical Exploration    2022, 46 (2): 316-322.   DOI: 10.11720/wtyht.2022.1182
Abstract259)   HTML43)    PDF (3517KB)(489)      

The understanding of the Paleogene Dongying formation and the Jixianian Wumishan formation have been gradually deepened with the exploration and development of deep thermal reservoirs in the Binhai New Area.This paper analyzes the hydrochemical characteristics, reservoir temperature, and hydrogeochemical effects of the geothermal fluid of the Dongying and Wumishan formations, thus providing bases for the further development and utilization of deep geothermal resources. The Wumishan formation in the Ninghe salient is adequately recharged. In contrast,the Dongying formation occursin a relatively closed environment, and the geothermal fluid in it is at a state of chemical equilibrium. The average temperature of the geothermal reservoirs in the Wumishan and Dongying formation scalculated using geothermometers is about 126 ℃ and 100 ℃, respectively. The geothermal fluid in both formations originates from atmospheric precipitation. Compared to the Wumishan formation, the geothermal fluidin the Dongying formation exchanges heat with rocks for a longer time and has a weaker cycling capacity. The runoff direction of the geothermal fluid in the formations is from northeast to southwest, with leaching, cation exchange, precipitation,and mixing mainly occurring during the fluid runoff.

Table and Figures | Reference | Related Articles | Metrics
Fine-scale prospecting targets of skarn iron deposits in the Pandian gravity-magnetic anomaly zone of northwestern Shandong Province: Insights from deep prospecting using the wide-field electromagnetic method
GUO Guo-Qiang, LI Ya-Dong, WANG Yang, YU Jia-Bin, WANG Run-Sheng, GAO Xiao-Feng, ZHANG Da-Ming, HU Dong-Ning, FANG Lei, GUO Wei-Fang
Geophysical and Geochemical Exploration    2024, 48 (2): 327-333.   DOI: 10.11720/wtyht.2024.1157
Abstract160)   HTML5)    PDF (4258KB)(286)      

Significant aeromagnetic and gravity anomalies were found in the ultra-deep coverage zone of the Pandian area in the northwestern Shandong Province. Through systematic verification of gravity and magnetic anomalies, a breakthrough in prospecting for deep skarn iron deposits has been achieved through several boreholes around the Pandian gravity-magnetic anomaly zone. However, the gravity-magnetic anomaly zone spreads extensively and its characteristics cannot directly indicate the prospecting target, thus some boreholes failed to find ores or revealed poor ore-finding conditions. Hence, to accurately delineate the ore-forming location in the gravity-magnetic anomaly zone and achieve a further breakthrough in ore prospecting, this study conducted the wide-field electromagnetic (WFEM) sounding in the verified Pandian gravity-magnetic anomaly zone. Combining the drilling verification, this study delineated the deep ore-forming interval of skarn iron deposits in the deep coverage zone and the favorable structural plane for ore-forming, suggesting the deep fine-scale prospecting targets.

Table and Figures | Reference | Related Articles | Metrics
Critical factors in microtremor-based exploration at a depth of thousands of meters
QI Juan-Juan
Geophysical and Geochemical Exploration    2024, 48 (3): 777-785.   DOI: 10.11720/wtyht.2024.1358
Abstract198)   HTML3)    PDF (6323KB)(285)      

To explore the critical factors influencing the results of microtremor-based exploration at a depth of thousands of meters,this study conducted experiments using triangular arrays based on spatial autocorrelation(SPAC) and extended SPAC(ESPAC).Focusing on factors such as array size,acquisition unit frequency,and acquisition duration,this study explored the frequency band ranges corresponding to different array sizes,the arrangement of arrays in kilometer-depth exploration for obtaining both deep and shallow data,and the improvement in deep resolution.Based on the analysis and discussion results,this study established a parameter-setting system to improve the accuracy of exploration at a depth of thousands of meters.

Table and Figures | Reference | Related Articles | Metrics
京ICP备05055290号-3
Copyright © 2021 Geophysical and Geochemical Exploration, All Rights Reserved.
Tel:(8610)62301569   Email:wt@caict.ac.cn