西昆仑阿什火山机构及岩石学、矿物学特征  

STUDY ON THE VOLCANIC EDIFICE AND PETROLOGICAL,MINERALOGICAL CHARACTERISTICS OF ASHI VOLCANO IN WEST KUNLUN MOUNTAINS

作　　者：申欢欢[1] 许建东[1] 于红梅[1] 赵波[1] 季灵运[2] 

机构地区：[1]中国地震局地质研究所,活动构造与火山重点实验室,北京100029 [2]中国地震局第二监测中心,西安710054

出　　处：《地震地质》2014年第1期105-122,共18页Seismology and Geology

基　　金：中国地震局地震行业专项(201008004);中国地震局地质研究所基本科研业务专项(IGCEA1101)共同资助

摘　　要：阿什库勒盆地位于NE向阿尔金断裂与NW向康西瓦断裂的“弧形”交会处,构造活动十分活跃,盆地内发育10余座火山,其中阿什火山为该火山群中最新活动的火山.文中从火山地质、熔岩和斑晶成分、显微结构特征及地质温压计4个方面对阿什火山进行了详细研究.结果表明,阿什火山由火山锥和熔岩流组成,锥体由早期的渣锥和晚期的溅落锥组成,熔岩流分布面积约33km2,可划分为4个流动单元.熔岩属于钾玄岩系列,岩性为粗安岩,显微镜下呈斑状结构.斑晶以长石（主要为中长石）和辉石（包括普通辉石、古铜辉石和紫苏辉石）为主；基质为玻璃质、隐晶质、微晶质,部分含有大量的长石和辉石.斑晶与岩浆的平衡温度为1 104～1 194℃,压力为570～980MPa,对应的岩浆房深度为18.92～32.29km.Ashikule Basin is located in the ＇ arc＇ intersection of NE-trending Ahyn Tagh Fauh and NW- trending Kangxiwar Fault, in which there are frequent tectonic activities, and more than 10 volcanoes are developed, including Ashi volcano, the latest active volcano in the Ashikule volcanic group. This paper conducts a detailed study on the Ashi volcano from four aspects, including volcanic geology, lava and phenocryst composition, microstructure features and geothermobarometer. The results show that Ashi volcano consists of volcanic cone and lava flow, and specifically the body of the cone is built by early scoria cone and later spatter cone and the lava flow with the area of about 33km2 is divided into four flow units. The lavas belong to shoshonite, trachyandesite in composition, and show porphyritic texture under microscope. The main phenocrysts are plagioclase （major in andesine）and pyroxene（including augite, bronzite and hypersthenes） ; The matrix is glassy, cryptocrystalline, and phaneritic, part of which has lots of feldspar and pyroxene microlites. The phenocryst-liquid equilibrium temperature is 1 104 - 1 194℃, and the equilibrium pressure is 570-980MPa, indicating that the depth of the magma chamber is about 18.92-32.29km

关 键 词：阿什火山 火山机构 粗安岩 显微结构 地质温压计 

分 类 号：P317.2[天文地球—固体地球物理学]