扩散年代学原理及其在岩浆体系研究中的应用  

The principles of diffusion chronometry and applications in magmatic systems

作　　者：陈厚彬 纪伟强[1] 张少华 CHEN HouBin;JI WeiQiang;ZHANG ShaoHua(State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地质与地球物理研究所,岩石圈演化国家重点实验室,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《岩石学报》2022年第5期1499-1511,共13页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(41888101、42072078)资助。

摘　　要：扩散年代学是近年来发展极为迅速的一种研究特定过程持续时间的方法,目前已在岩浆体系研究中得到了极大的应用。该方法利用精细的原位测试分析技术研究扩散环带,模拟各种岩浆过程中再平衡的时间尺度。本文对这种方法的原理、发展简史和研究基础做了全面的回顾,重点介绍了其在限定岩浆喷发各个过程时间尺度上的运用,包括岩浆分异和岩浆混合后在岩浆房中的滞留,喷发前岩浆从浅部岩浆房上升至地表过程,以及岩浆同化混染和去气作用。最后,对扩散年代学应用中可能存在的问题进行了讨论,包括如何选择扩散体系,如何区分生长与扩散效应,如何正确认识扩散的边界条件和各向异性等。Diffusion chronometry is a rapidly developing method for the study of different time scales over the past decades,and it has been widely applied in the study of magmatic systems.It requires high-spatial-resolution in-situ analysis to study diffusion-induced zoning and simulate the time scale of re-equilibration during various magmatic processes.This paper makes a comprehensive review of the principle,development history,and research basis of this method,with emphasis on its application to define the time scales of processes of volcanic eruptions.These processes include magma differentiation and retention in the magma chamber after magma mixing and ascent from the shallow magma chamber to the surface before the eruption,as well as magma assimilation,contamination,and degassing.Finally,we discuss the problems that may exist in applying diffusion chronometry,such as how to select a system that is suitable for diffusion modeling,how to distinguish growth and diffusion,the effect of boundary conditions,and diffusion anisotropy.

关 键 词：扩散年代学 岩浆过程 扩散时间 扩散环带 

分 类 号：P588.11[天文地球—岩石学]