东昆仑祁漫塔格希热芒崖晚石炭世花岗岩地球化学特征及其构造背景  

Geochemical Characteristics and Its Tectonic Setting of Xiremangya Late Carboniferous Granite in the Qimantage Mountains,East Kunlun

作　　者：陆济璞[1] 戴梅芳[2] 李江[1] 覃小锋[1] 许华[1] 

机构地区：[1]广西区域地质调查研究院,广西桂林541003 [2]青海省地质调查院,西宁810012

出　　处：《华南地质与矿产》2006年第4期1-8,共8页Geology and Mineral Resources of South China

基　　金：中国地质调查局基础地质调查项目(编号19991300008091)

摘　　要：希热芒崖花岗岩体由三次脉动侵位形成，主体岩性为斑状钾长花岗岩。全岩Rb—Sr等时线年龄为306．3Ma，时代属晚石炭世。岩石化学具有高硅、低铝、富碱、高钾、低钠、贫钙、镁、铁的特点。A／CNK=1．04，属过铝系列；∑REE平均值444．29×10^-6，∑Ce／∑Y平均值4．62，（La／Yb）N平均值3．75，δEu=0．03—0．22，为铕显著负异常。富集LILE和HFS如Rb，Th，Nb，Ta，U，Hf，Y及REE。Isr为0．79166，岩浆来源主要是地壳。利用主、微量元素特征进行构造环境判别为造山晚期，可能是晚石炭世板块消减俯冲导致地壳增厚并发生融熔形成的高钾钙碱性花岗岩。Xiremangya Late Carboniferous granite body is formed by three pulsating emplace and consist mainly of K-feldspar granite. The whole rock Rb-Sr isochron age of Xiremangya granite is 306.3 Ma, indicates that the granite body was intruded at late Carboniferous, It is petrochemically characteristized by enrichment of Si, K and alkalescence, poorness of Na, Ca, Mg and Fe. A/CNK = 1.04, which is peraluminous series. ∑REE = 444.29 × 10 - 6, ∑ce/∑Y = 4.62, （La/Yb） N = 3.75, δEu = 0.03 - 0.22, which is negative Europium abnormity, enrichment of LILE and IIFS （Rb, Th, U, Hf, Y） and REE. Isr = 0.79166, indicates that the magma is come from mainly the crust. The studies of Geochemistry indicate that Xiremangya granite body is characterized with late collision granite. The granite body might be mainly related to close of high-K calc-alkaline magma activity after the plate convergence and thickening of crust in late Carboniferous.

关 键 词：晚石炭世 高钾钙碱性花岗岩 地球化学 构造背景 造山晚期 东昆仑祁漫塔格 

分 类 号：P588.121[天文地球—岩石学]