
科学技术与工程

中国技术经济学会
Tectonic Stress Field in Guangxi and Surrounding Areas
Li-yang ZHENG , Yong-ge WAN
Science Technology and Engineering ›› 2025, Vol. 25 ›› Issue (6) : 2227 -2236.
Guangxi is located in the South China block, its structure is relatively stable, the seismic activity observed by the instrument is relatively weak. The little observation data leads to weak research on the crustal stress field in the area. In 2019, the Beiliu earthquake sequence occurrence in this area leads to the accumulation of considerable focal mechanism data. The focal mechanism data were collected in Guangxi and its adjacent areas. Using the grid search algorithm, the stress field in overall region and subregions were inverted. The results show as follows. The statistics of the focal mechanism in this area is mainly strike-slip type, and from the distribution of NW to ES, the focal mechanism of the reverse type gradually increases, and the focal mechanism of the normal fault type gradually decreases. The principal compressive stress axis of the overall stress field is NW-SE direction, the principal extensional stress axis is NE-SW direction, both of them are close to horizontal, which representing strike-slip type. The direction of the principal compressive stress axis in the western region is close to the N-E direction, and that in the east gradually changes to the direction of NW-SE, which makes the pattern of the compressive stress direction present a fan-shaped in the overall area. Based on the stress field analysis of subregions: NE-SW and NW-SE faults are easily generated in region-a by primarily of strike-slip type. NNE-SSW and NWW-SEE faults are easily generated in region-b, with NNE-SSW faults more towards reverse strike-slip type and NWW-SEE faults tending towards strike-slip type. Pure azimuth N-S and E-W faults are easily generated in region-c, but its main fault properties are not reflected due to the influence of surrounding fault extensions, with faults mainly of reverse strike-slip and reverse fault types. NW-SE and NE-SW faults are easily generated in region-d, with NW-SE faults more towards reverse fault and NE-SW faults tending towards strike-slip.
the Guangxi Beiliu earthquake sequence / focal mechanism / tectonic stress field / principal compressive stress / principal extensional stress
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