煤田地质与勘探2023，Vol.51Issue(12)：93-105,13.DOI:10.12363/issn.1001-1986.23.10.0673
福建地区上部地壳结构深地震测深探测研究
Revealing the upper crustal structure in the Fujian region using deep seismic profiling
摘要
Abstract
The Fujian region,located along the southeastern margin of the Chinese continent,constitutes an active tec-tonic belt along the coastal area in southeast China,with complex formation and evolution histories.To understand the characteristics of upper crustal structures and basement structures in the Fujian,this study collected the Pg travel time data from four NE-trending deep seismic sounding(DSS)survey lines in the region.Employing finite-difference tomo-graphy,this study obtained the fine-scale velocity structure of the upper crust along the four profiles,revealing the later-al variations in the upper crustal velocity structure,basement structures,and shallow fault characteristics in the region.Key findings are as follows:(1)The velocities along the four profiles range between 4 700 and 6 100 m/s,gradually in-creasing from west to east.They exhibit noticeable lateral variations in basement velocities on either side of tectonic unit boundaries.(2)The burial depth of crystalline basement interface along the four profiles varies between 1.0 and 6.0 km,deepening from north to south.The undulations in the basement surface correspond to the structural uplifts and depres-sions.(3)The upper structures in the uplift zone in northwest Fujian exhibit overall high velocities and shallow burial depths,which are related to the metamorphic basement.(4)Regarding the upper crust in the depression zone in southw-est Fujian,its structures exhibit significant variations velocities,and its interface morphology displays alternating pat-terns of deep and shallow parts.These correspond to the geological structures characterized by fault basins and depres-sions interlacing with uplifts in the region.(5)The upper crust of the Mesozoic magmatic zone along the coastal area in southeast China exhibits high and greatly varying velocities,indicating that stronger tectonic activity in the eastern part of South China Continent compared to its western part;(6)The NW-trending fault zone where the DSS profiles pass through cut through the basement,showing dominant strikes consistent with those of the geological structures and tec-tonic deformations in Fujian.This finding reflects the NW-directed subduction-collision compression from the Paleo-Pa-cific Plate.These findings provide shallow seismic evidence for obtaining significant depth relationships of NW-trend-ing structures along the coastal area in southeast China.关键词
福建地区/深地震测深剖面/有限差分层析成像/上部地壳结构/东南沿海Key words
Fujian region/deep seismic sounding profile/finite-difference tomography/upper crustal structure/south-east coast分类
天文与地球科学引用本文复制引用
李培,任丛荣,李海艳,王善雄..福建地区上部地壳结构深地震测深探测研究[J].煤田地质与勘探,2023,51(12):93-105,13.基金项目
国家自然科学基金项目(41474701) （41474701）
中国地震局地震行业科研专项项目(201508015) （201508015）
中国地震局地震科技星火计划项目(XH19024Y) （XH19024Y）
