摘要
若尔盖地区志留系内产出的众多铀矿床中含有层状、似层状、透镜状硅质灰岩,对其成因的研究有助于查明矿床成因和确定区域找矿方向。研究表明,硅质灰岩化学成分不稳定,以碱性CaO或酸性SiO_2为主。据硅质灰岩中蚀变矿物的微量元素地球化学特征,认为其流体主要来源于深部。从硅质灰岩的稀土配分看出,Ce/Ce*和Eu/Eu*值适中,硅质灰岩是海底喷流沉积的产物。硅质灰岩的δ^(13)C值偏高,具海洋沉积碳酸盐岩的碳同位素组成特征。在铀矿床中δ^(18)O值较高,表现为地幔来源的特点。U的矿化程度与Al_2O_3-MnO-Fe_2O_3含量呈正相关,与P_2O_5呈负相关,与SiO_2-CaO-K_2O-TiO_2-Na_2O-MgO组合呈显著负相关。
Many uranium deposits in the Zoigê region occur in Silurian which contains stratified, stratoid and lenticular siliceous limestone. Study of origin of the siliceous limestone is a great help to determination of regional range of reconnaissance. The study indicates that the siliceous limestone is production of submarine sedimentary exhalative process and characterized by medium Ce/Ce＊ and Eu/Eu＊ values, higher δ^（18） O and δ^（13） C values, showing mantle-derived features. The uranium mineralization has a positive correlation with Al2O3-Mn O-Fe2O3 content and a negative correlation with P2O5 and SiO2-CaO-K2O-TiO2-Na2O-MgO association.
作者
王永飞
李宝新
陈田华
张新民
董之凯
WANG Yong-fei;LI Bao-xin;CHEN Tianhua;ZHANG Xinmin;DONG Zhikai(Sichuan Institute of Uranium Geological Survey,Chengdu 610061)
出处
《四川地质学报》
2018年第2期225-230,244,共7页
Acta Geologica Sichuan
基金
四川省国土资源厅"四川省若尔盖县拉尔玛铀矿普查(川国土资函[2017]107号)"地勘基金项目资助
关键词
铀矿床
岩石学
地球化学
硅质灰岩
若尔盖
uranium deposit
petrology
geochemistry
siliceous limestone
Zoige
