黑龙江省东部早古生代晨明组物源区特征及其构造背景  

Provenance Characteristics and Tectonic Setting of Early Paleozoic Chenming Formation in Eastern Heilongjiang Province

作　　者：高福红[1] 何雨思 王枫[1] 修铭 Gao Fuhong;He Yusi;Wang Feng;Xiu Ming(College of Earth Sciences,Jilin University,Changchun 130061,China)

机构地区：[1]吉林大学地球科学学院,长春130061

出　　处：《吉林大学学报（地球科学版）》2018年第6期1725-1740,共16页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金项目(41272075)~~

摘　　要：为揭示黑龙江省东部早古生代晨明组沉积物源区特征及其沉积构造背景,对晨明组进行了地球化学特征研究。结果表明:晨明组岩石样品化学蚀变指数(ICA)值和斜长石蚀变指数(IPA)值较低、成分变异指数(ICV)值中等偏高,指示晨明组沉积物来源于不成熟的物质源区,并经历了较弱的化学风化作用和活动构造背景下的初次循环;LREE富集、HREE稳定和明显的负Eu异常,指示沉积物源区物质具有明显的上地壳特征且沉积物源岩为长英质火成岩;主量、微量和稀土元素特征共同指示晨明组形成于活动大陆边缘环境或大陆岛弧环境。结合前人研究成果,判定晨明组沉积物来源于经历了弱—中等程度化学风化作用的早古生代花岗质岩,沉积构造背景可能为靠近大陆岛弧的活动大陆边缘环境。To constrain the characteristics of sedimentary provenance and sedimentary tectonic setting of the Early Paleozoic Chenming Formation located in the eastern Heilongjiang Province,its geochemical characteristics were studied.The results show that the I CA and I PA values measured from the rock samples of Chenming Formation are relatively low,while their I CV values are moderate,indicating that the sediments of Chenming Formation came from an immature source,and experienced weak chemical weathering and initial circulation in an active tectonic environment.The enriched LREE,flat HREE pattern and obvious negative Eu-anomaly are suggestive to the obvious upper crustal characteristics of the materials in sedimentary provenance,and the source rocks of the sediments might be felsic igneous rocks.The geochemical analyses on major,trace elements as well as rare earth elements demonstrate that Chenming Formation might be deposited in an active continental margin or continental island arc environment.Combined with the previous literatures,the source rocks of Chenming Formation might be the Early Paleozoic granite,which were altered by weak to moderate weathering,and the sedimentary tectonic setting might be an active continental margin that was adjacent to island arcs.

关 键 词：黑龙江省东部 晨明组 地球化学 沉积物源区 构造背景 

分 类 号：P588.2[天文地球—岩石学]