大陆深俯冲的动力学机制:观测和模拟结果

doi:10.3321/j.issn:1000-0569.2005.04.026

CORC > 北京大学 > 地球与空间科学学院

	大陆深俯冲的动力学机制:观测和模拟结果; Dynamic mechanism of continental deep subduction: results from observation and simulation
	徐备 ; 张家声 ; 许鹤华 ; 张可丰 ; 方之楚 ; 单建新 ; 蔡永恩 ; 王化宇
刊名	岩石学报
	2005
关键词	帕米尔大陆深俯冲数值模拟 Pamier continental deep ubduction numerical simulation
DOI	10.3321/j.issn:1000-0569.2005.04.026
英文摘要	兴都库什-帕米尔-中国西部1975～2003年期间的地震活动记录、地表地质构造和地壳速度结构数据证明,沿特提斯陆-陆碰撞带正在进行大陆深俯冲作用。帕米尔地区大陆地壳的下部物质与上地幔一起俯冲到200km 以下,而中、上地壳在不同深度上被反冲断层所剥离。帕米尔地区向南的大陆深俯冲作用限于西部恰曼左行走滑断裂和东部喀喇昆仑右行走滑断裂之间。沿深俯冲带存在上、中、下3个地震群。上地震群出现在30～50km 附近,对应于中、上地壳的反冲剥离构造作用,地震成因与长英质地壳的脆-韧转换和“二相变形”机制有关。中地震群大体出现在90～120km 深度上,与帕米尔深俯冲岩板向下由缓倾变陡的深度大体相当。下地震...; Seismic record from 1975 to 2003, surface tectonics and crustal seismic velocity in Hindu kushi-Pamier-west China area show that a continental deep subduction is acting along Tethys continent-continent collision zone. Both lower crust and upper mantle are brought down to a depth more than 200 km, while mid-upper crust is overburdened by multiple back-thrusting in Pamier area. The continental deep subduction is restricted by Qiaman left-lateral strick slip faults in the west and Karakoron right-lateral strick slip faults in the east. Three seismic swarms occur along the deep subduction zone in vertical direction. The tipper seismic swarm presents in depth between 30 and 50 km, responding to the back-thrusting overburden of mid-upper crust. The middle swarm is concentrated around 90 similar to 120 km in depth comparable to a change position where the dipping angle of subducted slab becomes steeper downwards. The lower swarm occurs in a depth from 180 to 200 kin, representing the edge of the slab. Geometry of deep subducted slab in Pamier area shows a wedge narrowing downwards, with a change in subduction angle from 20 similar to 30 to 60 similar to 70 in 80 similar to 120 kin. Two numerical simulations have been used in the discussion about dynamics of the continental deep subduction. Two-dimensional numerical simulation with a given temperature field and negative buoyancy indicates that: (1) the mantle convection drag force plays an important control role to subducted depth and subducted rate. Its change from 100 MPa to 20 MPa results in decreases of the subducted depth from 231 kin to 151 km and subducted rate from, 10.79 mm/a to 5.46 mm/a; (2) The subducted depth of a subducted slab with a 30 degree angle is 25 similar to 50 kin more than that with a 45 degree angle. (3) Under the combined action of three kinds of dynamic load including a 10 similar to 30MPa push force of the mid-ocean ridge, negative buoyancy and the mantle convection drag force of 100MPa, the actual vertical displacement of the subducted continental crust can reach 117km and its final depth is 147km; the corresponding data for the subducted oceanic crust are 162km and 231km, respectively. In another model of coupled lithosphere and asthenosphere the LDDA and regional division methods are used. The model is characterized by the simple border conditions and the automatically acted effects between lithosphere and asthenosphere during subduction, but the mechanic parameters of different depths in different slabs must be given and calculating process is more complex.; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 1; 04; 1303-1310; 21
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/177933]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	徐备,张家声,许鹤华,等. 大陆深俯冲的动力学机制:观测和模拟结果, Dynamic mechanism of continental deep subduction: results from observation and simulation[J]. 岩石学报,2005.
APA	徐备.,张家声.,许鹤华.,张可丰.,方之楚.,...&王化宇.(2005).大陆深俯冲的动力学机制:观测和模拟结果.岩石学报.
MLA	徐备,et al."大陆深俯冲的动力学机制:观测和模拟结果".岩石学报 (2005).