地质论评2026，Vol.72Issue(1)：161-176,16.DOI:10.16509/j.georeview.2025.06.045
东天山亚勒曼一带下泥盆统头苏泉组火山岩地质、地球化学特征、U-Pb年龄及其构造意义
Geological,geochemical characteristics,U-Pb ages of the volcanic rocks from Lower Devonian Tousuquan Formation in Yaleman area,Eastern Tianshan Mountains,and their tectonic significance
摘要
Abstract
A set of intermediate and acid volcanic lava,volcanic tuff and volcanic breccia are developed in Yaleman Tousuquan Formation in the Eastern Tianshan Mountains.The magma evolved from neutral to acidic from early to late,and developed explosive facies,effusive facies and subvolcanic facies,characterized seven eruption rhythmic cycles.According to LA-ICP-MS zircon U-Pb isotopic dating,the rhyolite age of the Tousuquan Formation is 406.0±3.0 Ma(MSWD=0.35),and the age is early Devonian.Rock geochemistry shows that the volcanic rocks of Tousuquan formation have the characteristics of medium aluminum(13.2％～18.10％),rich in sodium and poor in potassium(K2O/Na2O=0.10～0.67),belonging to the high differentiation,low-to medium-K calc-alkaline series;The total amount of rare earth elements is relatively high(∑ REE=98.7× 10-6～214 × 10-6),LREE is enriched,HREE is depleted(LREE/HREE=3.75～4.58),Eu shows weak negative anomalies(δEu=0.62～0.92),large ion lithophile elements Rb,K,Ba are significantly enriched,and high field strength elements Nb,Ta and Ti are depleted.These geochemical characteristics exhibit signatures of mantle-derived remelted volcanic rocks that assimilated crustal materials during magma ascent,and indicate a continental margin arc tectonic setting related to subduction.关键词
头苏泉组/火山岩/火山韵律/早泥盆世/东天山Key words
Tousuquan Formation/volcanics/volcanic rhythm/Devonian/Eastern Tianshan Mountains引用本文复制引用
张亚光,邢伟伟,马梦玲,李强,姚鱼,李泽阳,夏祥,郭士恩..东天山亚勒曼一带下泥盆统头苏泉组火山岩地质、地球化学特征、U-Pb年龄及其构造意义[J].地质论评,2026,72(1):161-176,16.基金项目
本文为新疆维吾尔自治区地质勘查基金项目(编号:T15-1-LQ21)的成果. Thiss paper was supported by Geological Exploration Fund Project of Xinjiang Uygur Autonomous Region(No.T15-1-LQ21). （编号:T15-1-LQ21）
