摘要
层状侵入体的韵律层理是一种特殊的岩石构造,长期以来其成因倍受关注,成因假说很多。本文在综合这些观点以及关于岩浆物理、化学性质的研究,尤其是在岩浆房对流特征研究成果的基础上,提出了新的成因解释,认为固化带前锋处矿物的结晶、熔浆组分的扩散及固化带前锋本身的推进等3个因素的相互耦合是形成韵律层理的主要机制,这个过程是发生在一定过冷却条件下的。在这种定性认识基础上,笔者提出了旨在对韵律层理形成过程进行模拟计算的框架,建立了以化学动力学计算为核心的综合模拟计算方法,并对四川攀枝花岩体第Ⅱ岩相带的韵律层理进行了模拟。
Rhythmic layering is a special structure in layered intrusions and has long been studied by researchers of petrology, geochemistry and even chemistry. They have proposed many hypotheses to explain its formation. In this study, the authors propose a new model on the basis of synthesizing these hypotheses and results of studies of physical and chemical properties of magmas, particularly the results of studies of convections in the magmatic chamber. The authors hold that the main formation mechanism of layering is the coupling of crystallization and component diffusion of melt in the front of the solidification zone and advancement of the front itself and that this process occurs under supercooling conditions. From this view, the authors have proposed a pattern for formation simulation of rhythmic layering, built a compositive calculation method whose core is chemical kinetic calculation, and performed simulation of formation of the rhythmic layering in the second facies zone of the Panzhihua layered intrusion.
出处
《地质学报》
EI
CAS
CSCD
北大核心
1999年第1期37-46,共10页
Acta Geologica Sinica
基金
国家自然科学基金(编号49203044)
关键词
韵律层理
层状侵入体
定量模拟
过冷却
侵入岩
rhythmic layering
layered intrusion 5 quantitative simulation
supercooling
cou- pling
Panzhihua
Sichuan
