东昆仑拉宁灶火地区纳赤台群碎屑岩组合地球化学特征及其地质意义  

Geochemical characteristics and geological significance of clastic rocks of Naij Tal Group in Laningzaohuo area,East Kunlun

作　　者：靳立杰 周汉文[3] 刘伟 李春稼 王继林[4] 武志敬 赵前 田明阳 Jin Lijie;Zhou Hanwen;Liu Wei;Li Chunjia;Wang Jilin;Wu Zhijing;Zhao Qian;Tian Mingyang(No.1 Institute of Geology and Mineral Resource Exploration of Shandong Province,Ji'nan 250014;Shandong Engineering Laboratory for High‑Grade Fe Ores Exploration and Exploitation,Ji'nan 250014;China University of Geosciences(Wuhan),Wuhan 430074;Shandong Bureau Testing Center of China Metallurgical Geology Bureau,Ji'nan 250014;No.5 Geological Team of Shandong Provincial Bureau of Geology and Mineral Resources,Tai'an,Shandong 271000)

机构地区：[1]山东省第一地质矿产勘查院,济南250014 [2]山东省富铁矿勘查开发技术工程研究中心,济南250014 [3]中国地质大学(武汉),武汉430074 [4]中国冶金地质总局山东局测试中心,济南250014 [5]山东省地质矿产勘查开发局第五地质大队,山东泰安271000

出　　处：《地质科学》2024年第5期1280-1292,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国地质调查局“(J46E024013(黑海幅)、J46E024014(扎鲁塔斯幅)、I46E001013(红石沟幅)、I46E001014(加祖它士沟幅)、I46E001015(深沟幅)1∶5万区域地质调查”项目(编号:1212011086001)资助。

摘　　要：纳赤台群碎屑岩组合在东昆仑地区广泛出露,对恢复东昆仑地区原特提斯洋构造演化过程具有重要地质意义。本文通过对拉宁灶火沟地区的纳赤台群碎屑岩进行岩相学和地球化学研究,探讨了其风化作用条件、大地构造背景和物源特征。研究表明,拉宁灶火沟地区的纳赤台群碎屑岩主要由结构成熟度和成分成熟度较低的杂砂岩和岩屑砂岩组成,SiO_(2)含量为54.34%~76.06%,TFe_(2)O_(3)+MgO含量为3.25%~13.82%,稀土元素配分曲线呈现轻稀土富集、重稀土平坦的右倾模式,具有负δEu异常,无δCe异常。其较低的CIA值(53~74)和较高的ICV值(0.96~1.18)指示纳赤台群碎屑岩为干旱—温暖湿润气候下物源区母岩弱风化—中等风化的产物。构造背景判别图解显示,其主要物源应来自具有活动大陆边缘和大陆岛弧环境的石英质沉积物源区和长英质火成物源区,且存在古老沉积组分的加入。经对比分析认为,新元古代中酸性岩浆岩、早古生代弧花岗岩以及白沙河岩组、小庙岩群、万宝沟群为其主要物源。The Naij Tal Group clastic rocks are widely exposed in the East Kunlun,which has important geological significance for the restoration of regional tectonic evolution.In this paper,the weathering conditions,tectonic setting and provenance characteristics of the Naij Tal Group clastic rocks in the Laningzaohuo area are discussed through petrographic and geochemical studies.The results show that the Naij Tal Group clastic rocks in the study area are mainly composed of unstable wackes and litharenite.The content of SiO_(2) is 54.34%~76.06%,and the content of TFe_(2)O_(3)+MgO is 3.25%~13.82%.The REE patterns are characterized by LREE enrichment,flat HREE and negativeδEu anomalies.The low CIA values(53~74)and high ICV values(0.96~1.18)indicate that these sediments were derived from source rocks with low-moderate weathering and dry-warm humid climate.The tectonic setting discrimination diagrams show that the main provenance should come from quartzite sediment source area and felsic igneous provenance area with active continental margin and continental island arc.Moreover,there is the addition of ancient sedimentary components in the deposition process.According to the comparative analysis,the main provenances are the Neoproterozoic magmatic rock,the Early Paleozoic island arc granite,the Baishahe Formation,Xiaomiao Group and Wanbaogou Group.

关 键 词：纳赤台群碎屑岩组合 风化作用 构造背景 物源 东昆仑 

分 类 号：P588.21[天文地球—岩石学] P595[天文地球—地质学]