Investigating fault structure characteristics based on aeromagnetic data and precise relocation results of small earthquakes: A case study of the Panxi area
LI Jiao-Jiao(), ZHANG Yong-Jun, HE Yi-Yuan, LI Yi-Chuan, LI Shi-Jun, CHEN Yao
China Aero Geophysical Survey and Remote Sensing Center for Land and Resources, Beijing 100083, China
This study investigated the Panxi area as an example to delineate faults and determine their current activity levels using aeromagnetic data and precise relocation results of small earthquakes. A total of 42 faults were delineated in the study area. Among them, 21 faults were inferred to be active currently, including 10 newly inferred active faults. This study examined the three-dimensional structural characteristics of some local sections of major faults in the study area. The results indicate that precise relocation results of small earthquakes can identify highly active faults and characterize their deep structures. Additionally, based on the delineation of basement faults using aeromagnetic data, the locations of active faults were constrained, and concealed active faults within the sedimentary cover were also determined. The proposed method holds certain practical significance for promoting research on the spatial distribution and activity of fault structures using aeromagnetic data.
李皎皎, 张永军, 何怡原, 李逸川, 李诗珺, 陈瑶. 基于航磁与小震精定位结果研究断裂构造特征——以攀西地区为例[J]. 物探与化探, 2025, 49(1): 206-214.
LI Jiao-Jiao, ZHANG Yong-Jun, HE Yi-Yuan, LI Yi-Chuan, LI Shi-Jun, CHEN Yao. Investigating fault structure characteristics based on aeromagnetic data and precise relocation results of small earthquakes: A case study of the Panxi area. Geophysical and Geochemical Exploration, 2025, 49(1): 206-214.
Hu X J, Chen X J, Wu Y, et al. An analysis of the fault framework in southern Ningxia based on geophysical data[J]. Geophysical and Geochemical Exploration, 2023, 47(4):916-925.
Zhang Y J, Deng M S, Li J J, et al. Report of 1∶50,000 aeromagnetic survey in Panzhihua-Anyi area[R]. China Aero Geophysical Survey and Remote Sensing Center for Land and Resource, 2015.
Zhang G W, Lei J S, Xie F R, et al. Precise relocation of small earthquakes occurred in North China and its tectonic implication[J]. Acta Seismologica Sinica, 2011, 33(6):699-714,843.
Li L, Chen Q F, Chen Y. Relocated seismicity in Big Beijing area and its tectonic implication[J]. Progress in Geophysics, 2007, 22(1):24-34.
[12]
Waldhauser F, Ellsworth W L. A double-difference earthquake location algorithm:Method and application to the Northern Hayward fault,California[J]. The Bulletin of the Seismological Society of America, 2000, 90(6):1353-1368.
[13]
Fukuyama E, Ellsworth W L, Waldhauser F, et al. Detailed fault structure of the 2000 western Tottori,Japan,earthquake sequence[J]. Bulletin of the Seismological Society of America, 2003, 93(4):1468-1478.
Yang Z X, Chen Y T. Relocation of the 1998 Zhangbei-Shangyi earth-quake sequence using the double difference earthquake location algorithm[J]. Acta Seismologica Sinica, 2004, 26(2):115-120.
Yu X W, Chen Y T, Zhang H. Relocation of earthquakes in Beijing-Tianjin-Tangshan region with double-difference tomography technique[J]. Acta Seismologica Sinica, 2010, 32(3):257-269.
Zhu A L, Xu X W, Ren Y, et al. Relocation of the background seismicity and investigation on the buried active faults in Southeastern China[J]. Seismology and Geology, 2017, 39(1):67-80.
Zhu A L, Xu X W, Zhou Y S, et al. Relocation of small earthquakes in western Sichuan,China and its implications for active tectonics[J]. Chinese Journal of Geophysics, 2005, 48(3):629-636.
Fu Y, Long F, Wang S Y. Precise location of earthquakes at the eastern boundaries of diamond block of Sichuan-Yunnan[J]. Earthquake Research in China, 2018, 34(1):60-70.
[20]
四川省地质矿产局. 四川省区域地质志[M]. 北京: 地质出版社,1991.
[20]
Bureau of Geology and Mineral Resources of Sichuan Province. Regional geology of Sichuan Province[M]. Beijing: Geological Publishing House,1991.
[21]
刘家铎, 张成江, 李佑国, 等. 攀西地区金属成矿系统[M]. 北京: 地质出版社, 2007.
[21]
Liu J D, Zhang C J, Li Y G, et al. Mineralization system of metallic deposit in Panxi region[M]. Beijing: Geological Publishing House, 2007.
Deng Q D, Xu X W, Zhang X K, et al. Methods and techniques for surveying and prospecting active faults in urban areas[J]. Earth Science Frontiers (China University of Geosciences,Beijing), 2003, 10(1):93-104.
[22]
M7 Special Working Group. Study on the mid-to long-term potential of large earthquakes on the Chinese continent[M]. Beijing: Seismological Press, 2012.
Zhang X, Zhao L. A test study of urban faults using analytical method of magnetic anomaly[J]. Seismology and Geology, 2007, 29(2):336-353.
[23]
Xiong S B, Zheng Y, Yin Z X, et al. The 2D structure and it’s tectonic implications of the crust in the Lijiang-Panzhihua-Zhehai region[J]. Chinese Journal of Geophysics, 1993, 36(4):434-444.
Zheng G R, Lu J Z, Yu X Z. Fault structures and lithologic characters reflected by aeromagnetic survey in northern derbur,Inner Mongolia[J]. Geophysical and Geochemical Exploration, 2004, 28(5):388-393.
[24]
Fan Z G, Huang X Z, Xiong S Q, et al. Technical requirements for application of magnetic survey data[M]. Beijing: Geological Publishing House, 2010.
Fan Z G, Fang Y Y, Wang M J, et al. The application of aerogeophysical techniques to 1:250 000 regional geological mapping[J]. Geophysical and Geochemical Exploration, 2007, 31(6):504-509.
Zhang X J, Zheng G R, Fan Z L, et al. Structural characteristics of aeromagnetic deduced faults in western Tianshan mountains,Xinjiang[J]. Geophysical and Geochemical Exploration, 2011, 35(4):448-454.
Xiong S Q, Ding Y Y, Li Z K. A new understanding on the pattern of deep faults in Xizang and the southwestern Sanjiang area[J]. Chinese Journal of Geophysics, 2014, 57(12):4097-4109.
[25]
Cheng Y Z, Tang J, Chen X B, et al. Electrical structure and seismogenic environment along the border region of Yunnan,Sichuan and Guizhou in the south of the North-South seismic belt[J]. Chinese Journal of Geophysics, 2015, 58(11):3965-3981.
