岩矿测试2026，Vol.45Issue(5)：1092-1108,17.DOI:10.15898/j.ykcs.202511170277
基于矿物组分及晶胞参数特征定量划分川西二叠系火山岩相类型
Quantitative Classification of Permian Volcanic Facies in the Western Sichuan Basin Based on Mineral Composition and Unit Cell Parameter Characteristics
摘要
Abstract
There are significant lithological differences among different Permian volcanic facies in the western Sichuan Basin,and there is uncertainty in dividing volcanic facies based on petrological properties when samples are insufficient.In this work,techniques such as X-ray diffraction(XRD)Rietveld method,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)analysis,and polarizing microscope identification were employed to quantitatively characterize indicators of volcanic rocks including mineral composition,rock crystallinity,and plagioclase unit cell parameters,to divide the types of volcanic facies of the Permian period in different regions,as well as to analyze their intrinsic relationships.The results show that among the different Permian volcanic facies in western Sichuan,characteristic minerals exhibit differential enrichment patterns,rock crystallinity has different distribution ranges,and plagioclase unit cell parameters are significantly different.Specifically,chlorite,quartz,labradorite,and calcite are the characteristic minerals enriched in the explosive,effusive,subvolcanic,and volcano-sedimentary facies,respectively(average contents:43.14%,10.86%,38.99%,and 28.42%),with corresponding rock crystallinity ranges of 84.79%-100%,76.22%-91.06%,73.90%-97.28%,and 81.02%-100%.In the explosive facies,the a-b axis parameters and c-axis parameter of high-temperature albite show a strong positive correlation and a negative correlation with the unit cell volume V,respectively;in the effusive facies,the a-b axis parameters and c-axis parameter of plagioclase exhibit a weak positive correlation;in the subvolcanic facies,the a-b-c axis parameters of labradorite all show a positive correlation with the unit cell volume V;and in the volcano-sedimentary facies,the a-b axis parameters of low-temperature albite are negatively correlated,while the b-c axis parameters show a strong negative correlation.Based on these findings,a quantitative volcanic facies division method was established,which is based on the logical chain of"mineral content-mineral interrelationships-rock crystallinity-plagioclase crystal structure-volcanic facies type",providing a new insight for the accurate division of volcanic facies.关键词
X射线衍射/矿物组分/岩石结晶度/斜长石晶胞参数/火山岩相Key words
X-ray diffraction/mineral composition/rock crystallinity/plagioclase unit cell parameters/volcanic lithofacies分类
天文与地球科学引用本文复制引用
谭杰,王丽,冯明友,陈洪斌,严玉霞,谭雅倩,陈珺朗..基于矿物组分及晶胞参数特征定量划分川西二叠系火山岩相类型[J].岩矿测试,2026,45(5):1092-1108,17.基金项目
国家科技重大专项项目(2016ZX05007-004) （2016ZX05007-004）
国家自然科学基金青年基金项目(41202109) （41202109）
中国石油西南油气田公司科技项目(20200301-02) （20200301-02）
