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东昆仑早石炭世火山岩的地球化学特征及其构造背景 被引量:21

Geochemical Characteristics and Tectonic Setting of the Early Carboniferous Volcanic Rocks in East Kunlun Mountains
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摘要 东昆仑早石炭世火山岩主要沿昆中缝合带及其旁侧分布,岩性以玄武岩为主,之后亦有安山岩和英安岩产出,先后形成于洋脊、洋岛和岛弧构造环境。洋脊玄武岩K2O、P2O5、SiO2、REE含量和FeO/MgO比值低,钙、铁、镁高,轻重稀土元素分馏差。岛弧玄武岩硅、碱、铝和REE含量以及LREE/HREE比值高,镁、铁质低。洋岛玄武岩TiO2和P2O5高,K2O低,REE和LREE/HREE介于前二者之间。火山岩的构造背景表明,早石炭世昆中断裂带以“开”为主,形成洋脊玄武岩和洋岛玄武岩;早石炭世末转为“合”,形成岛弧型玄武岩、安山岩和英安岩。洋脊玄武岩的识别,对于研究区域构造及其演化甚为重要。 Early Carboniferous volcanic rocks in East Kunlun Mountains are distributed along Mid_Kunlun deep fault zone and consist mainly of basalts overlain by andesites and dactite. They were formed sequentially in setting of mid_ocean ridge, ocean island and island arc. The mid_ocean ridge basalt has lower K 2O, P 2O 5,SiO 2, REE, FeO */MgO and LREE/HREE values, and higher CaO, FeO * and MgO contents than the island_arc basalt. The ocean island basalt is characterized by highest TiO 2 and lowest K 2O contents, but its REE and LREE/HREE values are between values of the other two sorts of basalts. The study on the tectonic setting of the volcanic rocks shows that the Mid_Kunlun suture was dominantly in “spreading” state in Early Carboniferous, resulting in the formation of mid_ocean ridge basalt and ocean island basalt, and then evolved into “closing” state, giving birth to island_arc basalt, andesite and dacite at the end of Early Carboniferous. The identification of the ocean_ridge basalt is important to the understanding regional tectonics and its evolution.
出处 《岩石矿物学杂志》 CAS CSCD 北大核心 1998年第4期289-295,共7页 Acta Petrologica et Mineralogica
关键词 岩石分布 火山岩 地球化学 构造背景 tectonic setting tectonic geochemistry volcanic rocks tectonomagmatism Eastern Kunlun Mountains.
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  • 1许志琴,徐惠芬,张建新,李海兵,朱志直,曲景川,陈代璋,陈金禄,杨开春.北祁连走廊南山加里东俯冲杂岩增生地体及其动力学[J].地质学报,1994,68(1):1-15. 被引量:200
  • 2安三元,姜常义,胡能高.关于花岗岩成因问题的讨论[J]矿物岩石,1986(02).
  • 3杨经绥,柴耀楚,冯秉贵.东昆仑万宝沟群中的基性火山岩特征及其成因探讨[J]岩石矿物学杂志,1987(02).
  • 4肖序常,汤耀庆,高延林.再论青藏高原的板块构造[J]中国地质科学院院报,1986(03).
  • 5杨遵仪,李子舜,曲立范,卢重明,周蕙琴,周统顺,刘桂芳,刘本培,吴瑞棠.中国的三叠系[J]地质学报,1982(01).

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