Application of wide-field electromagnetic sounding method to deep prospecting in the Mangling ore concentration area in North Qinling: A case study of the Yaozhuang ore district
ZHANG Xiao-Tuan1(), LI Xin-Lin1,2(), ZHOU Bin1,2,3, GAO Wei-Qiang1
1. Shaanxi Institute of Geological Survey, Xi'an 710004, China 2. Shaanxi Geological Survey Planning Research Center, Xi'an 710068, China 3. School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China
The Mangling ore concentration area with intense magmatic activity has become a focal area for deep prospecting in the North Qinling tectonic belt in recent years. The formation of molybdenum deposits in this area is closely related to small Late Jurassic acidic intrusions. To achieve breakthroughs in deep ore prospection within this area, this study conducted the wide-field electromagnetic sounding over the concealed Yaozhuang intrusion delineated based on gravity anomalies. The results indicate the presence of pronounced high-resistivity anomalies at depth, and it is inferred that the protruding part of the anomalies corresponds to the concealed Yaozhuang intrusion. The resistivity inversion results roughly delineated the variations in the top surface of the intrusion, with the elevations and N-S width of the top surface estimated at -300~620 m and 1300~1600 m, respectively. Drilling in the most favorable deep mineralized part confirmed the presence of the concealed intrusion and concealed molybdenum ore bodies. The results of this study demonstrate that the wide-field electromagnetic sounding method exhibits great sounding depths and high resolutions, serving as an effective method for deep ore prospecting in the Mangling ore concentration area.
张晓团, 李新林, 周斌, 高维强. 广域电磁法在北秦岭蟒岭矿集区深部找矿中的应用——以腰庄矿区为例[J]. 物探与化探, 2024, 48(6): 1609-1617.
ZHANG Xiao-Tuan, LI Xin-Lin, ZHOU Bin, GAO Wei-Qiang. Application of wide-field electromagnetic sounding method to deep prospecting in the Mangling ore concentration area in North Qinling: A case study of the Yaozhuang ore district. Geophysical and Geochemical Exploration, 2024, 48(6): 1609-1617.
Lu X X, Luo Z H, Huang F, et al. “Small” magma and “big” fluid lead to form large scale deposit and transmagmatic fluid mineralization:Take for example of Mo deposits in eastern Qinling-Dabie mountain metallogenic belt[J]. Acta Petrologica Sinica, 2017, 33(5):1554-1570.
Ke C H, Wang X X, Li J B, et al. Geochronology and geological significance of the granites from the Mahe Mo deposit in the North Qinling[J]. Acta Petrologica Sinica, 2012, 28(1):267-278.
Ke C H, Wang X X, Yang Y, et al. Rock-forming and ore-forming ages of the Nantai Mo polymetallic deposit in North Qinling Mountains and its zircon Hf isotope composition[J]. Geology in China, 2012, 39(6):1562-1576.
Zhang Y H, Mao J W, Jian W, et al. Present status of research on molybdenum deposit in eastern Qinling and the problems remained[J]. Global Geology, 2010, 29(2):188-202.
[6]
Fan P, Xi A H, Zhou B, et al. Discovery of Yaozhuang stock and deep ore prospecting implication for the western mangling orefield in North Qinling terrane,Central China[J]. Frontiers in Earth Science, 2022, 10:830453.
Zhou B and Li X L. Research in deep prospecting and exploration technology and method of of porphyry-magmatic hydrothermal molybdenum deposit in Mangling area,North Qinling[C]// The 2nd National Mineral Exploration Conference, 2023.
Teng J W, Xue G Q, Song M C. Theory on exploring mineral resources in the second deep space and practices with electromagnetic method[J]. Chinese Journal of Geophysics, 2022, 65(10):3975-3985.
Teng J W. High-precision geophysics:The inevitable development track of the innovative future[J]. Chinese Journal of Geophysics, 2021, 64(4):1131-1144.
Yang H T, Liu X W, Wang C, et al. Geophysical and geochemical anomaly characteristics and ore prospecting model for the sigou porphyry-skarn type tungsten-molybdenum deposit in mangxi area[J]. Geology and Exploration, 2022, 58(5):929-939.
Cheng H J, Chen C, Zhan X Z, et al. New progress in the prediction theory and prospecting method for concealed deposits[J]. Geology and Exploration, 2017, 53(3):456-463.
Chen H Y, Li D Q, Ling F, et al. Deep exploration of wide field electromagnetic method in Zhuxi W-Cu deposit[J]. The Chinese Journal of Nonferrous Metals, 2022, 32(10):3227-3243.
He J S. New research progress in theory and application of wide field electromagnetic method[J]. Geophysical and Geochemical Exploration, 2020, 44(5):985-990.
[16]
何继善. 伪随机信号广域电磁法[M]. 北京: 高等教育出版社, 2023.
[16]
He J S. Wide-area electromagnetic method of pseudo-random signal[M]. Beijing: Higher Education Press, 2023.
Ling F, Zhu Y Z, Zhou M L, et al. Shale gas potential assessment of Changsan uplift area in southern North China basin by using wide field electromagnetic method[J]. Geophysical and Geochemical Exploration, 2017, 41(2):369-376.
Wang R S, Zhang B T, Liu S, et al. Application effects of the wide field electromagnetic method in the jinqingding gold deposit in Muping- Rushan metallogenic belt,Jiaodong peninsula[J]. Geology and Exploration, 2022, 58(2):381-390.
Shao B S, Ruan C X, Zhao S M, et al. The application of wide field electromagnetic method to deep geothermal resources exploration in Zhengzhou area[J]. Geology and Exploration, 2023, 59(2):316-327.
Wang D D, Zhang J D, Liu X F, et al. Application of the wide field electromagnetic method to Paleozoic oil and gas exploration in the Jiyuan depression of western Henan Province[J]. Geology and Exploration, 2023, 59(2):328-336.
Dong Y P, Zhang G W, Zhu B Q. Proterozoic tectonics and evolutionary history of the North Qinling terrane[J]. Acta Geosicientia Sinica, 2003, 24(1):3-10.
Wang H J, Xiong Y X. The application of wide field electromagnetic method to deep exploration in Jiaoxibei (northwest Shandong) gold concentration area[J]. Geophysical and Geochemical Exploration, 2020, 44(5):1039-1047.
Li D Q, Xiao J Y, Zhang J F, et al. Comparison of application effects of WFEM and CSAMT in water-rich area of Xinyuan Coal Mine[J]. Geophysical and Geochemical Exploration, 2021, 45(5):1359-1366.
Tang Z L, Qian Z Z, Jiang C Y, et al. Trends of research in exploration of magmatic sulfide deposits and small intrusions metallogenic system[J]. Journal of Earth Sciences and Environment, 2011, 33(1):1-9.
[26]
Sillitoe R H. Porphyry copper systems[J]. Economic Geology, 2010, 105(1):3-41.
Jin L Y, Qin K Z, Li G M, et al. Characteristics,controlling factors and exploration implications of porphyry molybdenum-hydrothermal vein-style lead-zinc-silver metallogenic systems[J]. Acta Petrologica Sinica, 2020, 36(12):3813-3839.
Zhou B, Fan P, Yang W B, et al. Report on metallogenic prediction and exploration demonstration of typical small rock masses in Shaanxi province[R]. Xi’an:Shaanxi geological survey planning research center, 2024.