火成岩岩性岩相特征及时空展布规律——以准噶尔盆地红山嘴地区石炭系火成岩为例

Characteristics of lithologic facies and space-time distribution of igneous rocks:a case study of Carboniferous igneous rocks in Hongshanzui Area,Junggar Basin

准噶尔盆地红山嘴地区火成岩岩性、岩相类型复杂且变化快,研究程度低。利用宏微观岩矿分析化验技术,结合地球物理测井、地震及全碱—二氧化硅质量分数分析等方法,开展火成岩岩石学、岩相学及时空展布规律研究。结果表明:研究区石炭系发育侵入岩、次火山岩、火山熔岩、火山碎屑熔岩、火山碎屑岩、沉火山碎屑岩六大类火成岩,以火山熔岩和火山碎屑岩为主;识别爆发相、喷溢相、次火山岩相、侵出相和火山沉积相5种岩相,建立符合岩性岩相识别图版。应用地球物理方法验证火成岩岩性鉴定结果并推广至未取心井,符合率达86.7%。平面上,研究区东部主要发育喷溢相火山熔岩,中西部主要发育爆发相凝灰岩。该结果为红山嘴地区石炭系火成岩勘探提供参考。

The lithology and lithofacies types of the igneous rocks in the Hongshanzui Area of the Junggar Basin are complex and change rapidly,and the research level is low.Using macroscopic and microscopic rock ore analysis and testing techniques,combined with geophysical logging,earthquake and total alkali-silica mass fraction analysis,the study of igneous petrology,petrography and space-time distribution is carried out.The results show that the study area is composed of six types:intrusive rocks,subvolcanic rocks,volcanic lava,volcanic clastic lava,volcanic clastic rocks and volcanic clastic rocks.Among them,volcanic lava and volcanic clastic rocks are dominant.Five types of facies,including the explosive facies,the effluent facies,the subvolcanic facies,the intrusive facies and the volcanic sedimentary facies were identified,and the lithologic facies identification maps corresponding to the volcanic facies were established.The lithology identification results of igneous rocks were verified by geophysical methods and extended to untreated core wells,and the coincidence rate was over 86.7%.On the plane,the volcanic lava is mainly developed in the eastern part of the study area,and the eruptive tuff is mainly developed in the central and western parts.The results have guiding significance for the exploration of Carboniferous igneous rocks in the Hongshanzui Area.