腾冲火山壳幔过渡带分析及岩浆上涌通道初探  

Study of the Crust-Mantle Transition Zone and Magma Upwelling Conduits Beneath the Tengchong Volcano Area

作　　者：范心甜 危自根 谢军 程智伟 凌媛 李雪垒 刘益炜 FAN Xintian;WEI Zigen;XIE Jun;CHENG Zhiwei;LING Yuan;LI Xuelei;LIU Yiwei(State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,Hubei,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Earth Sciences and Engineering,Hebei University of Engineering,Handan 056038,Hebei,China;Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;School of Microelectronics and Physics,Hunan University of Technology and Business,Changsha 410205,Hunan,China)

机构地区：[1]中国科学院精密测量科学与技术创新研究院,大地测量与地球动力学国家重点实验室,湖北武汉430077 [2]中国科学院大学地球与行星科学学院,北京100049 [3]河北工程大学地球科学与工程学院,河北邯郸056038 [4]中国科学院地质与地球物理研究所地球和行星物理重点实验室,北京100029 [5]湖南工商大学微电子与物理学院,湖南长沙410205

出　　处：《地震研究》2025年第1期41-48,共8页Journal of Seismological Research

基　　金：国家自然科学基金(42474094,42306084);湖北省自然科学基金(2023AFB1076).

摘　　要：壳幔过渡带是地壳与地幔物质和能量的交换场所,其结构特征与该区的深部过程和构造演化密切相关。提取腾冲火山区31个地震台站下方的接收函数H-κ叠加获得的地壳厚度随频率变化特征和接收函数的Ps/P、PpPs/P振幅比,发现盈江断裂北部的黑空山-燃灯寺和南侧沙坝台区域具有比周边区域更低的振幅比,约有2 km地壳厚度差异。将该观测结果与前人获得的这两个区域相对薄的地壳厚度与高的V_(P)/V_(S)比值相结合,表明黑空山-燃灯寺和沙坝台区域具有厚的壳幔过渡带,推测其是地幔物质涌入地壳的通道。结合前人获得的该区上、中、下地壳都存在大片低速体的特征,推测来自地幔的岩浆很可能沿着腾冲火山区黑空山-燃灯寺和沙坝台这两个区域上涌到地壳,并依次在下、中和上地壳富集和横向展布,最终沿多个通道喷出地表。The Crust-Mantle transition zone serves as a critical interface for the exchange of material and energy between the Earth's Crust and Mantle,closely tied to deep processes and tectonic evolution in the region.This study extracts characteristics of crustal thickness variation with frequency from receiver functions H-κstacking beneath 31 seismic stations in the Tengchong volcanic area,as well as the Ps/P and PpPs/P amplitude ratios of the receiver functions.It reveals that the Heikongshan-Randengsi area to the north of the Yingjiang fault and the Shabatai area to the south exhibit lower amplitude ratios and a crustal thickness difference of approximately 2 km compared to surrounding regions.Combining these observations with previous findings of relatively thin Crust and high V_(P)/V_(S)ratios in these two areas suggests a thick Crust-Mantle transition zone,hypothesized as conduits for Mantle material into the Crust.Building on previous findings of extensive low-velocity features in the upper,middle,and lower Crust of the region,this paper postulates that magma from the Mantle likely ascends through the Crust along the Tengchong volcanic area,specifically through the regions of Heikongshan-Randengsi and Shabatai.Subsequently,it enriches and laterally spreads within the lower,middle,and upper Crust,eventually erupting onto the surface through multiple channels.

关 键 词：腾冲火山 接收函数 振幅比 地壳厚度 壳幔过渡带 地幔上涌通道 

分 类 号：P317[天文地球—固体地球物理学]