scholarly journals Identification of gold mineralization zones of low sulfidation epithermal systems using geoelectrical and magnetic methods in Ciparay area, Cibaliung

2021 ◽  
Vol 10 (3) ◽  
pp. 70-79
Author(s):  
Wahyu Eko Junian ◽  
Agus Laesanpura ◽  
Andri Yadi Paembonan ◽  
Muhammad Arief Wicaksono

Abstrak. Cibaliung merupakan daerah pertambangan mineral yang berada di Provinsi Banten. Hal ini, dibuktikan dengan adanya lubang tambang emas di daerah Cikoneng dan Cibitung. Penelitian tentang geofisika penting dilakukan guna menemukan cadangan emas baru di daerah Ciparay yang terletak di Sebelah Tenggara Cikoneng dan Cibitung. Metode geofisika yang digunakan di antaranya magnetik, resistivitas, dan induced polarization (IP). Metode magnetik digunakan sebagai survei pendahuluan untuk menggambarkan keberadaan struktur geologi pengontrol mineralisasi emas. Melalui peta reduce to pole dapat diketahui adanya tanda-tanda keberadaan struktur geologi yang ditunjukkan oleh anomali negatif (-220 hingga -135 nT) di Bagian Barat Daya daerah penelitian. Hasil teknik edge detectors menunjukkan adanya pola struktur dengan arah Northwest (NW) dan North-Northeast (NNE) yang dominan berada di Bagian Barat Daya sebelah Utara daerah penelitian. Metode resistivitas dan IP digunakan sebagai survei detail untuk menentukan keberadaan mineral yang terkandung dalam batuan. Hasilnya menunjukkan bahwa zona potensi mineralisasi ditunjukkan oleh anomali tinggi (resistivitas 50 ohm.m dan chargeability 40 msec). Resistivitas tinggi diduga sebagai respons batuan induk andesitic sedangkan, nilai chargeability tinggi merupakan respons dari hadirnya mineral-mineral bijih seperti emas dan perak. Zona potensi mineralisasi berada pada posisi patok 350-800 dengan arah persebaran mengikuti arah struktur geologi pengontrolnya yaitu NW dan NNE. Abstract. Cibaliung is a mineral mining area located in Banten Province. The area including gold mining in Cikoneng and Cibitung areas. Geophysical research is important to find new gold reserves at the Ciparay area, located in the Southeast of Cikoneng and Cibitung. Geophysical methods used include magnetic, resistivity, and IP. The magnetic method was applied as a preliminary survey to delineate the presence of the geological structure controlling the gold mineralization. Based on the RTP map, signs of the presence of geological structures are shown by anomalies -220 to -135 nT in the Southwestern part of the study area. The results of edge detector techniques show the existence of structural patterns in the direction of NW and NNE which are dominant in the Southwestern North of the study area. The resistivity and IP methods are employed for detailed investigation in order to obtain to determine the presence of minerals contained in rocks. The results show that the mineralized zones are indicated by high resistivity ( 50 ohm.m) and high chargeability ( 40 msec). High resistivity response is caused by andesitic source rock whereas, high chargeability response is related to the presence of ore minerals such as gold and silver. The mineralization prospect zone is indicated at the position of 350-800 and its direction corresponds to the direction of its geological structure namely NW and NNE.Keywords: New gold reserves, Negative magnetic anomalies, High resistivity, High chargeability. 

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1393
Author(s):  
Mingchun Song ◽  
Guoqiang Xue ◽  
Hongbo Liu ◽  
Yixin Li ◽  
Chunyan He ◽  
...  

The North China Craton is one of China’s major gold-producing areas. Breakthroughs have been continually made in deep prospecting at depths of 500–2000 m in the Jiaodong Peninsula, and geophysical methods have played an important role. Given that the geophysical signals of deep-seated gold deposits are difficult to detect, due to their thick overburden layers, conventional geophysical methods are not suitable for deep prospecting. Therefore, this study upgrades the geological-geophysical prospecting model, which is based on the deep metallogenic model and geophysical method of large exploration depths. Based on the analysis of the metallogenic geological factors of the altered-rock-type gold deposits in the fracture zones of the Jiaodong Peninsula, this study proposes that the gold deposits are controlled by large-scale faults, generally occur near the contact interfaces between the Early Precambrian metamorphic rock series and Mesozoic granitoids, and exhibit a stepped metallogenic model. This model then becomes the prerequisite and basic condition for deep prospecting by geophysical methods. For this reason, the traditional geophysical model, which focuses on the exploration of shallow mineralization anomalies, is transformed into a comprehensive multi-parameter geological-geophysical qualitative prospecting model highlighting the exploration of ore-controlling structural planes. The model adopts various frequency domain methods (e.g., CSAMT, AMT, WFEM), reflection seismology, and other methods to detect the deep geological structure. The characteristics of parameters such as gravity and magnetism, resistivity, polarizability, and the seismic reflection spectrum are applied to identify the ore-controlling fault location and dip angle change, and to estimate the ore-bearing location according to the stepped metallogenic model. The prospecting demonstration of deep-seated gold deposits in the Shuiwangzhuang mining area indicates the effectiveness of the comprehensive model. The comprehensive deep prospecting model effectively solves the problem of deep prospecting of gold deposits controlled by faults, promotes the great breakthrough of deep prospecting in the Jiaodong Peninsula, and provides an important technology demonstration for deep prospecting throughout China.


2016 ◽  
Vol 47 (3) ◽  
pp. 1355
Author(s):  
G. Vargemezis ◽  
N. Diamanti ◽  
I. Fikos ◽  
A. Stampolidis ◽  
Th. Makedon ◽  
...  

Ground penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys have been carried out in the city centre of Thessaloniki (N. Greece), for investigating possible locations of buried building foundations. Geophysical survey has been chosen as a non-destructive investigation method since the area is currently used as a car parking and it is covered by asphalt. The geoelectrical sections derived from ERT data in combination with the GPR profiles provided a broad view of the  subsurface.  Regarding  ERT,  high  resistivity  values  can  be  related  to  buried building remains, while lower resistivity values are more related to the surrounding geological materials. GPR surveying can also indicate man-made structures buried in the ground. Even though the two geophysical methods are affected in different ways by the subsurface conditions, the processed underground images from both techniques revealed great similarity. High resistivity anomalies and distinct GPR signals were observed in certain locations of the area under investigation, which are attributed to buried building foundations as well as the geological structure of the area.


2019 ◽  
Vol 16 (2) ◽  
pp. 117
Author(s):  
Ayi Nurhidayah ◽  
Sri Cahyo Wahyono ◽  
Simon Sadok Siregar

This research has been done in the mining area of andesite rock of Awang Bangkal village by using magnetic method. Magnetic method is one of the most common geophysical methods used for preliminary surveys on petroleum, earth, and mineral rock exploration. It is intended to determine the subsurface distribution in the area by performing qualitative and quantitative interpretations based on the magnetism value of the earth. The result of data processing using geosoft oasis montaj software shows that the total magnetic field anomaly is -807,3 to -361,7 nT. Qualitative interpretation is done by looking at the contour map of the anomaly, the result of upward continuation and the reduction to the poles. While the interpretation is done by making a modeling of the path that has been determined using mag2dc software. The model shows that the rocks that dominate the area are andesite rocks with their susceptibility value of 0.0992 to 0.2305 in SI units.


2018 ◽  
Vol 149 ◽  
pp. 02076
Author(s):  
Bahi Anas ◽  
Akhssas Ahmed ◽  
Ouadif Latifa ◽  
Ahmed Ait Errouhi ◽  
Kawtar Ouatiki

Geophysical methods are one of the best ways to determine the potential of a mining area. Indeed, for the prospection of metalliferous deposits, the magnetic method remains essential as it makes it possible to characterize the extent and the depth of the anomalous bodies present in the prospected zone, mainly due to their reaction with the values of the total magnetic field. Thus, for the manganese mining zone of Bouarfa and more exactly Hammraouet, the genesis of the deposit is such that the manganese is generally associated with ferruginous minerals and clearly affect the total magnetic field. That said, the raw results obtained must imperatively be subjected to corrections to only keep the effect of the anomalous bodies on the magnetic field. Hence, we must proceed with the correction of the daytime effect then we eliminate the regional effects to get the map of the residual anomaly and finally we perform a reduction to the pole that will allow us to have well individualized and unipolar anomalies and thus allowing us to locate precisely the potentially mineralized axes. The synthesis of the various maps obtained by spatial interpolation of the data recorded in situ and corrected allows us to locate areas of mining interest and to determine the different tectonic phenomena that took place in our study area. In time, these maps will serve us to guide the subsequent mechanical surveys to confirm the results obtained by geophysical methods.


2016 ◽  
Vol 47 (3) ◽  
pp. 1355
Author(s):  
G. Vargemezis ◽  
N. Diamanti ◽  
I. Fikos ◽  
A. Stampolidis ◽  
Th. Makedon ◽  
...  

Ground penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys have been carried out in the city centre of Thessaloniki (N. Greece), for investigating possible locations of buried building foundations. Geophysical survey has been chosen as a non-destructive investigation method since the area is currently used as a car parking and it is covered by asphalt. The geoelectrical sections derived from ERT data in combination with the GPR profiles provided a broad view of the  subsurface.  Regarding  ERT,  high  resistivity  values  can  be  related  to  buried building remains, while lower resistivity values are more related to the surrounding geological materials. GPR surveying can also indicate man-made structures buried in the ground. Even though the two geophysical methods are affected in different ways by the subsurface conditions, the processed underground images from both techniques revealed great similarity. High resistivity anomalies and distinct GPR signals were observed in certain locations of the area under investigation, which are attributed to buried building foundations as well as the geological structure of the area.


2020 ◽  
Author(s):  
Tatiana Shirokova ◽  
Ivan Lygin ◽  
Tatiana Sokolova

<p>Currently, the integration of seismic and "non-seismic" geophysical research methods is increasingly demanded by the practice of exploration. Further improvement of the efficiency of the complex of seismometry and gravimetry, its wide introduction into practice, requires both the creation of recommendations on the methodology of joint interpretation of these methods, and the determination of limitations on the scale of surveying and the specifics of the considered cross-sections, affecting the effectiveness of the methods of the studied geological structures. The aim of the presented work is to identify the main factors that determine the limits of applicability of seismic-gravity modeling.</p><p>The possibilities of seismic-gravity modeling in conditions of different physical and geological structure of the considered environment, scale, level and quality of the initial data were investigated on real objects. It is shown that it is impossible to totally formalize a single approach (algorithmize) to the creation of a seismic-gravity model. The modeling technique inevitably changes, adapts to the physical and geological situation and the completeness and detail of a priori information. Against the background of numerous positive examples of use, the situations difficult for seismic-gravity modeling are given and analyzed carefully and the reasons for the low efficiency of the method are revealed.</p><p>The experience of practical research has shown that the effectiveness of seismic-gravity modeling is primarily influence by such features of geological structure as the extent of compartmentalization of the reflector horizons’ geometry, contrast and depth of the density boundaries, the accordance of seismic and gravity exploration (both field survey and target exploration intervals), the intricacy of the geological history of the region.</p><p>The findings are important at the design stage of field work to compile a set of geophysical methods, the most effective for this area of study.</p>


2021 ◽  
Author(s):  
Adam Cygal ◽  
Michał Stefaniuk ◽  
Anna Kret

AbstractThis article presents the results of an integrated interpretation of measurements made using Audio-Magnetotellurics and Seismic Reflection geophysical methods. The obtained results were used to build an integrated geophysical model of shallow subsurface cover consisting of Cenozoic deposits, which then formed the basis for a detailed lithological and tectonic interpretation of deeper Mesozoic sediments. Such shallow covers, consisting mainly of glacial Pleistocene deposits, are typical for central and northern Poland. This investigation concentrated on delineating the accurate geometry of Obrzycko Cenozoic graben structure filled with loose deposits, as it was of great importance to the acquisition, processing and interpretation of seismic data that was to reveal the tectonic structure of the Cretaceous and Jurassic sediments which underly the study area. Previously, some problems with estimation of seismic static corrections over similar grabens filled with more recent, low-velocity deposits were encountered. Therefore, a novel approach to estimating the exact thickness of such shallow cover consisting of low-velocity deposits was applied in the presented investigation. The study shows that some alternative geophysical data sets (such as magnetotellurics) can be used to significantly improve the imaging of geological structure in areas where seismic data are very distorted or too noisy to be used alone


2018 ◽  
Vol 18 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Bin Zeng ◽  
Tingting Shi ◽  
Zhihua Chen ◽  
Liu Xiang ◽  
Shaopeng Xiang ◽  
...  

Abstract. The solution mining of salt mineral resources may contaminate groundwater and lead to water inrush out of the ground due to brine leakage. Through the example of a serious groundwater inrush hazard in a large salt-mining area in Tongbai County, China, this study mainly aims to analyse the source and channel of the inrushing water. The mining area has three different types of ore beds including trona (trisodium hydrogendicarbonate dihydrate, also sodium sesquicarbonate dihydrate, with the formula Na2CO3 × NaHCO3 × 2H2O, it is a non-marine evaporite mineral), glauber (sodium sulfate, it is the inorganic compound with the formula Na2SO4 as well as several related hydrates) and gypsum (a soft sulfate mineral composed of calcium sulfate dihydrate, with chemical formula CaSO4 × 2H2O). Based on characterisation of the geological and hydrogeological conditions, the hydrochemical data of the groundwater at different points and depths were used to analyse the pollution source and the pollutant component from single or mixed brine by using physical–chemical reaction principle analysis and hydrogeochemical simulation method. Finally, a possible brine leakage connecting the channel to the ground was discussed from both the geological and artificial perspectives. The results reveal that the brine from the trona mine is the major pollution source; there is a NW–SE fissure zone controlled by the geological structure that provides the main channels through which brine can flow into the aquifer around the water inrush regions, with a large number of waste gypsum exploration boreholes channelling the polluted groundwater inrush out of the ground. This research can be a valuable reference for avoiding and assessing groundwater inrush hazards in similar rock-salt-mining areas, which is advantageous for both groundwater quality protection and public health.


2014 ◽  
Vol 936 ◽  
pp. 2383-2388
Author(s):  
Zhi Wen Li ◽  
Cheng Dong Liu ◽  
Xuan Qing Zhao ◽  
Jian Hui Lu ◽  
Guo Lin Guo

Using the analysis techniques of polarizing optical microscope and electron probe, mineral composition, ore texture and structure and the occurrence of Au in the primary ore are studied. The research shows that the main ore minerals in the ore include realgar, pyrite and arsenopyrite etc. Sulfur-stibarsen is the main carrier of Au, and is the major associated mineral of realgar, surrounded mainly by realgar, and partly is the associated mineral of arsenopyrite. The existence of visible gold and microscopic gold in the ore of this mining area can be excluded, and the gold might exist mainly in the form of inclusion gold, which is the so-called “nanoAu”.


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