摘要
通过对内蒙古东北部恩和村晚石炭世二长花岗岩开展岩石地球化学研究,分析其岩石地球化学特征、岩石成因及所揭示的区域构造背景。研究表明,晚石炭世二长花岗岩的w(SiO_2)为75. 51%~76. 46%,w(Al_2O_3)为12. 09%~12. 92%,全碱w(K_2O+Na_2O)为7. 26%~7. 67%,K_2O和Na_2O质量分数比值为1. 60~2. 94,属于高钾钙碱性系列。所有样品的稀土配分曲线具有相似的特征,稀土丰度总量δ为111. 9~131. 6μg,轻重稀土分馏明显,(La/Yb)N为1. 10~2. 67,Eu负异常(0. 08~0. 11),微量元素以富集大离子亲石元素Rb、Ba,高场强元素Zr、Ta、Nb相对于大离子亲石元素亏损为特征。晚石炭世二长花岗岩岩浆来源于地壳,形成环境为张性环境,部分可能产生于造山期后构造环境。
This paper aims to elucidate geochemistry, petrogenesis and tectonic setting of the intrusion and presents the major and trace element geochemistry data for the monzogranite intrusion in the Enhecun from northeastern Inner Mongolia. The results show that the monzogranite samples are characterized by high SiO 2 （75.51% -76.46%）, high alkali （K 2O＋Na 2O）（7.26% -7.67%）, low Al 2O 3 （12.09% - 12.92%）, with the w （K 2O）/ w （Na 2O） rations ranging from 1.60 to 2.94; the monzogranite belongs to high-K calc-alkaline series; all of the samples have similar REE patterns, the total Rare Earth Element（REE） contents of these rocks range from 111.9 to 131.6 μg;the monzogranite is enriched in LREE and relatively depleted in HREE with high （La/Yb） N rations（1.10-2.67） and significant negative Eu anomaly （ δ Eu 0.08-0.11）; they are both enriched in large ion lithophile elements（Rb、Ba） and relatively depleted in high field strength elements（Zr、Ta、Nb）; and the primary magma of the monzogranite originates from the crust, with regional tectonic evolution, partly from post-collisional extension setting.
作者
商宇航
陆胜
吴宪涛
王键
Shang Yuhang;Lu Sheng;Wu Xiantao;Wang Jian(School of Mining Engineering,Heilongjiang University of Science ＆ Technology,Harbin 150022,China;The Fifth Geological Prospecting Institute of Heilongjiang Province,Harbin 150090,China)
出处
《黑龙江科技大学学报》
CAS
2018年第5期499-503,共5页
Journal of Heilongjiang University of Science And Technology
基金
黑龙江省自然科学基金项目(QC2018044)
关键词
二长花岗岩
地球化学
晚石炭世
内蒙古东北部
monzogranite
geochemistry
Late Carboniferous
northeastern Inner Mongolia
