克92井区火山岩地层格架与岩相研究

A STUDY ON STRATIGRAPHIC SEQUENCES AND LITHOFACIES OF THE IGNEOUS ROCKS IN KE WELL-92 REGION

火山喷溢具有成层性和韵律性。因此,火山活动期次是划分、对比火山岩地层的基本单位,期次的确定能够较好地解决新疆准噶尔盆地西北缘石炭系火山岩地层划分与对比问题。尝试性地利用岩性和电性特征统计结果,描述了火山岩期次变化规律,揭示了不同期次火山岩变化特征。并采用岩性组构分类方法开展了克92井区石炭系火山岩岩相研究,通过对火山岩岩石类型、火山物质搬运方式、火山作用产物及其配置关系研究,建立了火山岩岩相划分方法和分布模式,提出火山岩岩相由火山口亚相—近火山口亚相—熔岩台地亚相—火山沉积亚相和次一级微相组成;并在地层划分基础上描述了不同期次、不同火山口喷发物的岩性及空间分布范围。

Volcanic eruption is layered and rhythmic,so,the stages of volcano activities are the basic units dividing and correlating volcanic rock formations.The determination of stages can be helpful to solve the problems of division and correlation of carboniferous volcanic rock formations in the northwest rim of Junggar Basin,Xingjiang.In this paper,the results of statistics of lithologic and electronic characteristics are probed to describe the law of stage change of volcanic rocks,and the characteristics of volcanic rock change in different stages are revealed.The method of lithologic texture division is used to study carboniferous volcanic lithology in Ke well-92 region,by researching the types of volcanic rocks,transporting means of volcanic materials,the products of volcanic action and the disposing relationship,the dividing ways and the distributing model of volcanic lithologic facies are set up,it is presented that volcanic lithologic facies are composed of crater sub-facies,near crater sub-faices,lava platform sub-facies,volcanic sedimentary sub-facies and secondary level mocro-facies,and the lithology and special distribution of different stages and different volcanic eruptive materials are described based on lithologic division.