| 长江中下游铜陵矿集区深部地壳结构——来自宽频地震P波接收函数成像的证据 |
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| 关键词:Tongling ore concentration area crustal structure P-wave receiver function velocity ratio underplating |
| 基金项目:中国地质调查局地质调查项目“地质调查科技创新发展与新技术推广研究”(编号: DD20221829)；“羌塘盆地油气资源调查评价与战略选区”(编号: DD20233002)；“全国油气重点调查区战略性矿产调查评价”(编号: DD20233001) |
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| Deep Crustal Structure of the Tongling Ore Concentration Area in the Middle-lower Reaches of the Yangtze River: Evidence from Teleseismic P-wave Receiver Functions |
| The Tongling Ore Concentration Area, located in the central part of the mineralization belt in the middle and lower reaches of the Yangtze River, has experienced large-scale tectonic deformation and magmatic activity since the Mesozoic. Its crustal structure is of great significance in understanding the collision process of the South-North China blocks as well as the dynamics of Mesozoic mineralization in the middle and lower reaches of the Yangtze River and throughout South China. In this study, the crustal structure of the Tongling Ore Concentration Area in the middle and lower reaches of the Yangtze River was investigated using P-wave receiver function imaging of 49 teleseismic events recorded at 26 broadband seismic stations. The results showed that a velocity discontinuity with a depth of approximately 2–3 km exists in the shallow part of the crust, which may be the interface between the basement and overlying strata. In the Hamaling area of southern Tongling, it deepens towards the two flanks of the Yongcunqiao Anticline. The Moho depths in Tongling and its surrounding areas are about 29–32 km with weak lateral variation and certain thickness, which indicates that the Moho beneath Tongling is probably a “transition zone” but not a “sharp interface.” The average Vp/Vs ratio was approximately 1.79, which is higher than normal and suggests a more mafic crust in the region. The lower crustal thickness and higher wave velocity ratio in this region suggest that the Tongling Area may have experienced crustal thinning and basaltic underplating. Our results suggest that large-scale magmatism in the middle-lower reaches of the Yangtze River during the Mesozoic was likely associated with magmatic emplacement at the base of the crust in Tongling. |
| ZHAO Rongtao,LIU Shasha,YANG Yan,HUANG Shi,ZHENG Kai,SHI Danian.2024.Deep Crustal Structure of the Tongling Ore Concentration Area in the Middle-lower Reaches of the Yangtze River: Evidence from Teleseismic P-wave Receiver Functions[J].Acta Geoscientica Sinica,45(6):965-976. |
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