豫西熊耳山北岭金矿区马家河组安山岩地球化学特征及其地质意义  

Geochemical characteristics of andesites from the Majiahe Formation in the Beiling gold deposit and their geological significance

作　　者：李肖龙[1,2] 申硕果[3] 黄丹峰[2] 李敏 叶萍 茹朋 程国安 Ll Xiao-long;SHEN Shuo-guo;HUANG Dan-feng;LI Min;YE Ping;RU Peng;CHENG guo-an(School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China;Henan Institute of Geological Survey/Henan Key Laboratory of Metallogenic Geological Processes and Resource Utilization, Zhengzhou 450001, China;Henan Provincial Rock and Mineral Testing Center, Zhengzhou 450012, China;Henan Institute of Geological Sciences, Zhengzhou 450001, China)

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]河南省地质调查院河南省金属矿产成矿地质过程与资源利用重点实验室,河南郑州450001 [3]河南省岩石矿物测试中心,河南郑州450012 [4]河南省地质科学研究所,河南郑州450001

出　　处：《岩石矿物学杂志》2019年第3期287-302,共16页Acta Petrologica et Mineralogica

基　　金：国家重点研发计划项目(2016YFC0600504-02);中国地质调查局项目(121201004000150017-59;121201004000160901-18);河南省自然科学基金项目(182300410106)~~

摘　　要：北岭金矿位于豫西熊耳山地区,矿区内的围岩主要为熊耳群马家河组火山岩。本文对马家河组安山岩进行了详细的岩石学、地球化学研究,旨在确定其岩石成因和形成的构造背景。研究结果表明,马家河组安山岩高碱,尤其富钾;稀土元素总量(ΣREE)为154. 60×10^(-6)～200. 60×10^(-6),轻稀土元素相对富集,具有弱的Eu负异常;岩石富集U、K、Pb、Nd等大离子亲石元素(LILE),亏损Th、Nb、Ta、Ce、Zr、Ti等高场强元素(HFSE);马家河组安山岩具有幔源岩浆的特征,其源区可能受到俯冲组分的改造使其地球化学特征发生变化;岩浆在演化过程中经历了单斜辉石、斜长石等的分离结晶。结合其他资料分析认为,马家河组安山岩形成于大陆裂谷环境,可能是华北克拉通的伸展、裂解事件的产物。The Beiling gold deposit,located in western Henan Province,is mainly hosted in the Majiahe Formation. The rocks are composed of basaltic andesites and andesties. In this paper,the petrological and geochemical characteristics of the volcanic rocks were studied to constrain the petrogenesis. The result shows that the volcanic rocks of the Majiahe Formation are rich in alkali,especially in K2 O. The mafic-intermediate rocks are characterized by a relatively low abundance. Their total amount of rare earth elements(ΣREE) is 154. 60 × 10^-6~ 200. 60 ×10^-6. They forms a LREE-enriched distribution [( La/Yb)N= 6. 72 ~ 8. 22] with the existence of weak negative Eu anomaly. In addition,the rocks display LILE enrichment( such as U,K,Pb and Nd) and HFSE depletion( such as Th,Nb,Ta,Ce,Zr and Ti). The chemical data presented in the paper show that the Majiahe Formation rocks had a modified mantle source with ancient subduction belt materials. It is suggested that these volcanic rocks experienced a crystal fractionation process during the magmatic evolution. Comprehensive research shows that the Majiahe Formation was formed under a continental rifting environment.

关 键 词：北岭金矿 马家河组 安山岩 地球化学 熊耳山地区 

分 类 号：P588.144[天文地球—岩石学] P595[天文地球—地质学]