西秦岭台乌龙一带晚三叠世华日组火山机构及演化  

THE VOLCANIC APPARATUS AND EVOLUTION OF TRIASSIC HUARI FORMATION IN TAIWULONG AREA OF WEST QINLING

作　　者：李康宁 

机构地区：[1]甘肃省地矿局第三地勘院,甘肃兰州730050

出　　处：《甘肃地质》2017年第4期10-17,共8页Gansu Geology

基　　金：中国地质调查局项目"青海省同仁县多哇地区I48E005001;I48E005002两幅1:50000区域地质矿产调查(编号:12120114018220)";"甘肃省夏河-合作地区金矿整装勘查区矿产调查与找矿预测(编号:121201004000160901-60)"联合资助

摘　　要：西秦岭地区的构造演化是许多地质学家普遍关注的问题。三叠纪以来西秦岭发生了复杂的俯冲碰撞造山作用,这一时期发育的火山岩,便是这一地质事件的重要记录。本文选取西秦岭甘青交界处台乌龙一带华日组火山岩为研究对象,运用"火山旋回—火山构造—火山地层—岩性岩相"的火山岩区填图方法,在华日组火山岩中识别出喷溢相、爆发相、侵出相、喷发—沉积相、火山通道相和次火山岩相等6个岩相;台乌龙层状火山机构、色日欠破火山机构等11个火山机构;两个组合样式(台乌龙—年支北串珠式组合、下毛娘北—色日欠镶嵌式组合);划分出1个火山喷发旋回,3个亚旋回。较合理地建立起地层层序、岩相相序和演化模式。华日组火山岩的出现标志着西秦岭地区在晚三叠世已进入陆相演化阶段。The tectonic framework of the West Qinling area is a common concern of many geologists. There has been a complex subduction collision orogeny in the West Qinling since the Triassic, the volcanic rocks developed during this period are important records of this geological event. The volcanic rocks of the Huari Formation in the Taiwulong area at the Ganqing junction of the West Qinling Mountains were mapped by volcanic cycle-volcanic structure-volcanic stratigraphy-volcanic rock facies to get four conclusions that we identified： six rock facies including effusive facies, explosive facies, extrusion facies, eruption-deposition facies, volcanic conduit facies and subvolcanic rock facies; eleven tectonic apparatus including Taiwulong layered volcanic apparatus and Seriqian caldera volcanic apparatus etc; two conbination patterns including moniliforme type conbination of Taiwulong-Nianzhi North and mosaic type conbination of Seriqian-Xiamaoniang North; one volcanic eruption cycle and three subcycles. These studies have rationally established stratigraphic sequence,lithofacies sequence and evolutionary patterns. The presence of volcanic rocks in the Huari Formation indicates that the West Qinling area has entered the continental evolution phase in the Late Triassic.

关 键 词：火山岩相 火山机构 火山旋回 火山演化 

分 类 号：P534.51[天文地球—古生物学与地层学] P588.14[天文地球—地质学]