摘要
新疆西北部阿拉套山南坡的花岗岩体的40Ar-39Ar和K-Ar定年结果表明它们都是海西期侵入体。侵入活动可分为三个阶段:最早的是东部的岩基,岩性为花岗间长岩和钾长花岗岩,年龄约305Ma,而后是西部的二长花岗岩和钾长花岗岩,与钨锡成矿有关,年龄约290Ma;最晚的是最西部的二长花岗岩,年龄约280~270Ma。岩浆活动中心有自东或北东向西或南西迁移的趋势。
More than ten granite bodies are outcropped along the south slop of the Alatao Mountains, northwest Xinjiang Uygur Autonomous region. This area belongs to the the north branch of the Tianshan fold belt. Granites here occur in batholith stockes and their rock types are of granodiorite to mozogranite. KuAr and 40Ar-39Ar dating were performed for 12 biotite samples from 9 rock bodies.The results show that all bodies were emplaced during Variscan orogeny and that they were formed at three stages. Older granodiorites and monzogranites located in the east part of the region were intruded at 305Ma ago. Many monzogranites and alkaline feldspar granites in the west part of region were intruded at 290 to 300Ma ago.The youngest granites outcropped in the west were intruded at about 270 to 280 Ma ago. Tin and tungsten deposits are associated with the granites intruded the second stage. All rock bodies were emplaced Onto a more high level of crust and cooled quickly. The center of magma activities removed from the esst (or northeast) to the west (southwest) with time.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
1994年第2期184-192,共9页
Acta Petrologica Sinica
基金
"七五"国家新疆305攻关项目
关键词
花岗岩
K-Ar定年
同位素定年
Granite
K-Ar dating
(~40)Ar-^(39) Ar daton
Alatao Mountians
Xijiang