西北地质2018，Vol.51Issue(2)：57-68,12.
华北板块西南缘河西堡中酸性侵入岩岩石地球化学和环境演化特征
Geochemical and Environmental Characteristics of Hexipu Medium-acid Intrusive Rocks in the Southern Margin of North China Plate
摘要
Abstract
The Hexipu medium-acid intrusive rock is located at the intersection area between the Qilian orogenic belt and the Longshou mountain of the southwestern margin of North China Carton,which is composed of fine grained quartz diorite,medium-fine grained granodiorite,mediumcoarse grained porphyritic granodiorite and medium-coarse grained porphyritic monzogranite.The Hexipao granitic plutons are enriched in K and Si,but depleted in Al,Ca and Mg,having weakly negative Eu anomalies.Chondrite-normalized REE patterns show that all samples are enriched in LREEs.The δEu values of the ploutons are rising with the increasing of the SiO2,∑REE,∑LREE/∑HREE and La/Yb.The 87Sr/86Sr ratios of all samples vary from 0.706 0 to 0.707 8,these plutons have been transited from early I type to I-S type to S type,showing a complete process of transiting from plate compression to collisional orogeny.Combined with the regional geological data,the results show that the North Qilian was subducted into the North China craton in Early Caledonian to form a trench-arc-basin system,the compression was led to the midCaledonian collisional orogeny between the North Qilian and Longshou mountain,and this collisional stage was terminated in Late Caledonian,systematically reflecting the tectonic evolution of the Longshoushan orogenic belt.关键词
中酸性侵入岩/河西堡/弧后扩张/碰撞造山Key words
medium-acid intrusive rock/Hexipu/back-arc spreading/collisional orogeny分类
天文与地球科学引用本文复制引用
丑永魁,张翔,马永东,杨涛,王玉玺..华北板块西南缘河西堡中酸性侵入岩岩石地球化学和环境演化特征[J].西北地质,2018,51(2):57-68,12.基金项目
中央财政出资的基础地质研究类项目“J48E009001(西坡幅)、J48E010001(河西堡幅)、J48E011001(东寨乡幅)1∶5万区域地质调查项目(2001GB13)” （西坡幅）
