摘要
采用Li等和Gao等归纳的中国东部主要构造单元地壳速度结构研究中国东部下地壳组分特征。对下地壳的岩性推测通过两个方面展开:1通过实测地壳P波波速与Christensen等实测的不同岩性P波波速进行对比;2采用Hasterok等提出的P波波速-密度转换方法,将下地壳速度结构转化为密度结构,并采用Monte Carlo法对密度的误差进行估算。结果表明:中国东部各构造单元下地壳P波波速与基性岩类相当,绝大多数构造单元下地壳密度大于3 000kg·m-3,该密度范围对应的岩性是基性岩类。因此,中国东部下地壳是基性的。
Based on crustal velocities of the main tectonic units in the eastern China summarized by Li et al.and Gao et al.,the lower crustal composition beneath the eastern China was discussed.Predictions of the lower crustal composition have two aspects：comparing the observed P-wave velocities between the crust and the various rocks measured by Christensen etal.;transferring the lower crustal velocity model to density model,according to the relationship between P-wave velocity and density proposed by Hasterok et al.,and the errors of density are estimated by Monte Carlo method.The results show that P-wave velocities of the lower crust of the main tectonic units in the eastern China correspond with those of mafic rocks;most of the densities of the lower crust are greater than 3 000kg·m^（-3）,which belong to mafic rocks.Therefore,the lower crust beneath the eastern China is suggested to mafic in composition.
出处
《地球科学与环境学报》
CAS
2016年第6期849-858,共10页
Journal of Earth Sciences and Environment
基金
中央高校基本科研业务费专项资金项目(2652013021)
关键词
下地壳
地震波速
密度
基性岩
岩石物理
岩性
华北
中国东部
lower crust
seismic wave velocity
density
mafic rock
petrophysics
lithology
North China
the eastern China
作者简介
王纪庆（1991-），女，吉林松原人，工学硕士研究生，E-mail：wiiqing1001@163．com。
通讯作者：汪洋（1969-），男，浙江杭州人，教授，理学博士，E-mail：allen_thalassa@sina．com。
