盆地火山岩相分类和模式  

Classification and Model of Volcanic Facies in the Basin

作　　者：唐华风[1] 边伟华[1] 王璞珺[1] 高有峰[1] 黄玉龙[1] 张艳[1] 户景松 Tang Huafeng;Bian Weihua;Wang Pujun;Gao Youfeng;Huang Yulong;Zhang Yan;Hu Jingsong(College of Earth Sciences,Jilin University,Changchun 130061,China)

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《吉林大学学报(地球科学版)》2023年第6期1651-1671,共21页Journal of Jilin University:Earth Science Edition

基　　金：吉林省重点研发计划项目(20230203107SF);国家自然科学基金项目(41790453)。

摘　　要：盆地火山岩相模式是储层分布规律和识别的重要基础,目前遇到了地层单位不一致、钻井揭示不系统和盆地间存在差异大的问题。基于此,需要建立一套系统的基本地层单位的相模式。本文总结了相、岩相、火山岩相的相关定义,梳理了针对地质填图、矿产普查、现代火山和盆地火山岩研究的火山岩相分类方案的特点。本文认为利用出露好的现代火山研究成果指导盆地火山岩相研究是首选的研究方式。针地火山地层堆积单元,突出岩石组构和几何外形要素,厘定了5相15亚相44微相的火山岩相划分方案。相和亚相分别是爆发相的热碎屑流、(热)基浪、火山碎屑裙和火山碎屑筒亚相,喷溢相的水上熔岩流、水下熔岩流和水上喷发水下就位熔岩流亚相,侵出相的水上熔岩穹丘、水下熔岩穹丘和早期水下晚期水上熔岩穹丘亚相,火山-沉积相的火山泥石流和崩塌堆积亚相,次火山岩相的岩脉、岩盖和岩盆/岩席亚相,进一步指出了各微相的特征岩石结构构造。不同化学成分的熔岩可以形成相同的亚相或微相,如流纹岩和玄武岩均可以形成喷溢相水上熔岩流亚相复合熔岩流微相,流纹岩、英安岩、安山岩和玄武岩均可形成侵出相水上熔岩穹丘亚相。从储层来看,复合熔岩流微相好于水上熔岩穹丘亚相的各类微相,所以本文的分类方案可以建立起亚相或微相与储层的细划对应性关系。相关认识可用于盆地火山岩相对比和储层预测。Volcanic facies model in the basin is an important basis for reservoir distribution and identification.There are still some problems including stratigraphic unit inconsistency,unsystematic drilling,and large differences between basins.It is necessary to establish a system of facies models of basic stratigraphic units.This paper summarizes the definitions of facies,lithofacies and volcanic facies.Volcanic facies are divided into three classification schemes,which are for geological mapping and mineral survey in field,modern volcanoes and volcanic rocks in basin.It is considered that it is preferancial to apply the modern volcanic research results to guide the study of volcanic facies in the basin.The deposited units of volcanostratigraphy highlight the elements of rock fabric and geometric shape,and the volcanic facies division scheme of 5 facies,15 subfacies and 44 microfacies is summarized.The eruptive facies is divided into pyroclastic flow,base surge,volcaniclastic apron,and volcaniclastic diatreme subfacies.The effusive facies is divided into subaerial lava flow,subaqueous lava flow,and subaerial eruption-subaqueous emplacement lava flow subfacies.The extrusive facies is divided into subaerial lava dome,underwater lava dome,and early subaqueous-late subaerial lava dome subfacies.The volcano-sedimentary facies is divided into lahar and debris avalanche subfacies.The subvolcanic facies is divided into dikes,laccolith and sill/lopolith subfacies.The characteristics of the fabric and structure of each microfacies are pointed out.Lava with different chemical compositions can form the same subfacies or microfacies.For example,rhyolite and basalt can both form the braided lava flow subfacies of the subaerial lava flow,while rhyolite,dacite,andesite,and basalt can all form the subaerial lava dome.With respect to the reservoir potential,the braided lava flow microfacies is better than the various microfacies of the subaerial lava dome.Therefore,the classification scheme in this paper can establish a detailed correlati

关 键 词：火山岩 火山岩相 相模式 地层单元 火山地层学 盆地 

分 类 号：P618.13[天文地球—矿床学]