摘要
西昆仑塔什库尔干一带苦子干碱性杂岩体是区内最大的新生代碱性杂岩体,关于该岩体与稀土成矿的关系尚不明确。通过野外实地调查和镜下鉴定,对苦子干碱性杂岩体的地质背景进行了调查,并利用主微量元素分析方法对岩石地球化学特征进行了研究。结果表明:苦子干碱性杂岩体各类岩石总体稀土元素含量较高,富集LREE,具有较好的稀土矿找矿前景;苦子干碱性杂岩体主要呈Ce、Y富集特征,且与F元素正相关;赋矿(化)岩石为中粒霓辉正长岩,含萤石、磷灰石和独居石等副矿物,围岩为中粒石英正长岩,二者呈渐变接触,接触界线不明显。
Kuzigan alkaline intrusive complex is the largest Cenozoic alkaline complex in the Taxkorgan area of West Kunlun.In recent years,the research on the Kuzigan alkaline complex has mainly focused on the formation age of the rock mass and the source of magmatic materials,but little research has been done on its rare earth mineralization characteristics.Based on the geological background and petrochemical characteristics of Kuzigan complex,the metallogenic characteristics of this type of rare earth ore in Kuzigan area were discussed by means of field investigation,microscopic identification and main trace element analysis.Three samples were taken from aegirine syenite and one contrast sample was taken from syenogranite.The results show that the total rare earth content of all kinds of rocks in the alkali metasomatic rare earth ore of Kuzigan is rich,mainly manifested as Ce and Y enrichment,and positively correlated with F.The REE content of syenite varies from 888.05×10-6 to 1320.17×10-6,and it is enriched in light rare earth elements(LREE/HREE=13.54~19.65).The curves in the REE chondrite normalized diagram is generally right-leaning,and the differentiation degree of LREE and HREE is not large as a whole.No obvious anomalies of Eu and Ce are found,which has the common characteristics of alkaline syenite.The range of LREE fractionation parameter (La/Sm)N is 3.80 to 26.75.The HREE fractionationdegree parameter (Gd/Yb)N varies from 2.94 to 7.98,indicating that the syenite has slight fractionation on bothlight and heavy rare earths,but the fractionation degree of light rare earth is greater than that of heavy rare earth.The ore-bearing rock of rare earth ore(mineralization) in the Kuzigan alkaline complex is medium-grainedaegirine syenite,which contains accessory minerals such as fluorite,apatite and monazite,and is located nearthe internal contact zone with medium-grained quartz syenite,the two are in gradual contact. The Kuziganalkaline complex has high REE content and strong LREE enrichment,which is mainly characterized byenrichment of light rare earth elements such as Ce and Y,and is positively correlated with F.It has the prospectof finding alkaline metasomatic rare earth deposits,and should focus on strong potassic,aegirine and carbonatealteration zones.
作者
杨佐怀
郭艳琴
陆诗超
段留安
李峥伟
黎小勇
魏彦强
苏飞
杨国良
YANG Zuohuai;GUO Yanqin;LU Shichao;DUAN Liu’an;LI Zhengwei;LI Xiaoyong;WEI Yanqiang;SU Fei;YANG Guoliang(College of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an 710065,Shaanxi,China;Urumqi Comprehensive Survey Center on Natural Resources,China Geological Survey,Urumqi 830057,Xinjiang,China;Key Laboratory of Shaanxi Province for Petroleum Accumulation Geology,Xi’an 710065,Shaanxi,China;Yantai Coastal Geological Survey Center,China Geological Survey,Yantai 264001,Shandong,China)
出处
《黄金科学技术》
CSCD
2023年第2期262-270,共9页
Gold Science and Technology
基金
中国地质调查局二级项目“塔里木南缘边境(省界)线100公里内战略性矿产规划支撑调查”(编号:ZD20220229)资助。
关键词
成矿特征
稀土
碱性杂岩体
苦子干
西昆仑
metallogenic characteristics
rare earth
alkaline complex rock mass
Kuzigan
West Kunlun
