地质通报2018，Vol.37Issue(4)：655-668,14.
阿尔金南缘玉苏普阿勒克塔格北侧冰沟南组变质火山岩地球化学特征及其地质意义
Geochemical characteristics and geological signifi-cance of Binggounan Formation meta-volcanic rocks on the northern side of Yusupualeketage at the southern edge of the Al-tun Mountains
摘要
Abstract
The Binggounan Formation volcanic rocks on the northern side of Yusupualeketage at the southern edge of the Altun Mountains are a suite of basic volcanic rocks associated with littoral neritic facies terrigenous clastic rocks and carbonate rock. The gneiss rocks are composed mainly of basalt-andesite and andesitic tuff lava.Geochemical analysis shows that the SiO2content of the rocks is between 48.28% and 51.98% with an average of 50.31%.The rocks have rich alkal and low titanium.The Rittman index(δ) is 0.33~2.30 and the aluminum saturation index(A/CNK)is 0.45~0.88,suggesting calc-alkaline series.The value of Mg#is between 40.46 and 56.28,with an average of 50.12.It is shown that the basic volcanic rocks experienced higher crystallization differentiation, suggesting a weaker right-inclined LREE enrichment type.Eu anomaly is not obvious,and δEu is between 0.81 and 1.17.Lithophile elements Rb,Ba,K,Sr and high field strength elements P,Ti,Nb,Hf are depleted,and incompatible elements Th,U are enriched, implying incompatible enrichment type. The trace elements and rare earth elements have the characteristics of intraplate basalt. Ac-cording to the tectonic environment discrimination series diagram and the comprehensive analysis, the basic volcanic rocks were formed in an inner-plate rift environment.The regional plate breakup of the Paleoproterozoic continent occurred from Changcheng period to the early Qingbaikou period, forming basic volcanic rocks. In the late Qingbaikou period, the evolution began to turn to the Rodinia supercontinent squeeze convergence stage.关键词
冰沟南组/变质火山岩/地球化学/板内裂解/阿尔金南缘Key words
Binggounan Formation/meta-volcanic rocks/intraplate breakup/geochemistry/southern margin of Altun Mountains分类
天文与地球科学引用本文复制引用
赵江林,曾忠诚,陈宁,李琦,张若愚,王星,杜彪,袁璋..阿尔金南缘玉苏普阿勒克塔格北侧冰沟南组变质火山岩地球化学特征及其地质意义[J].地质通报,2018,37(4):655-668,14.基金项目
中国地质调查局项目《新疆阿尔金地区1:5万J45E010020等六幅区域地质矿产调查》(编号:12120114081901) （编号:12120114081901）
