摘要
伊犁板块南北缘广泛发育石炭纪火山岩。其中阿希、巩乃斯和恰西石炭纪火山岩主要由玄武岩、安山玄武岩、玄武粗安岩、粗安岩和粗面岩组成,为基性冲性-酸性连续岩系,以中基性岩为主;它们多为钙碱性岩;轻稀土较重稀土元素富集,富集大离子亲石元素Rb,Ba,Th,U,K,相对亏损高场强元素Nb,Ta,Ti,具有大陆边缘火山岛弧火山岩亲缘性。其可能形成于准噶尔洋向南俯冲于伊犁板块之下的大陆边缘岛弧环境,伊犁板块南缘火山岩也有可能产出于南天山洋向伊犁-中天山板块之下俯冲的岛弧环境。
Carboniferous volcanic rocks are widespread at Yili region. Geochemical data of volcanic rocks from Axi, Gengnaisi and Qiaxi of Yili region suggests that they belong to calc-alkalic series, and consist of basalt, basaltic andesite, basaltic trachy-andesite, trachy-andesite and trachyte, which is the continued rock series from basic-intermediate-acid volcanic rocks. They are enriched in LREE relative to HREE, rich in Rb, Ba, Th, U, K and have a low concentrations of Nb, Ta, Ti. It suggests that they have a blood relation with volcanic-arc rocks and may be created by the sudbuction of the Junggar Ocean toward south beneath the Yili plate. The volcanic rocks from the south margin of the Yili plate could also be related to the subduction of the South Tianshan Ocean towards north beneath the Yili-Central Tianshan plate.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第4期699-710,共12页
Acta Petrologica Sinica
基金
国家重点基础研究发展规划项目(编号:2007CB411304)
国家自然科学基金(编号:40672153和40721062)
中国科学院“百人计划”项目资助。
关键词
新疆
伊犁板块
火山岩
地球化学
构造环境
Xinjiang
Yili plate
Volcanic rocks
Geochemistry
Tectonic setting
