摘要
三塘湖盆地汉水泉地区是东准噶尔地区砂岩型铀矿找矿的有利地段,为揭示该地区中侏罗统西山窑组和头屯河组沉积物物源体系,分析地层铀源条件,对西山窑组和头屯河组砂岩开展碎屑锆石LA-ICP-MS U-Pb测年和Hf同位素分析。分析结果显示西山窑组砂岩的碎屑锆石年龄集中于晚古生代,2个样品年龄峰值分别为328 Ma和340 Ma,碎屑锆石ε_(Hf)(t)为8.9~14.7,二阶段模式年龄介于690~415 Ma之间;头屯河组砂岩的碎屑锆石年龄可划分出238~163 Ma、505~259 Ma和1950~744 Ma 3个区间段,碎屑锆石ε_(Hf)(t)为-6.5~12.1,二阶段模式年龄介于1709~575 Ma之间。物源分析表明西山窑组砂岩物源单一,主要来自于研究区西部卡拉麦里—麦钦乌拉和野马泉地区;头屯河组砂岩物源相对复杂,除了有来自于卡拉麦里地区的碎屑物质外,还接受了其他区域的物源供给。二者之间碎屑锆石年龄特征的突变,代表了东准噶尔地区中侏罗世一次剧烈的构造变形事件,物源特征指示汉水泉地区中侏罗统地层铀含量相对有限,铀源是限制该地区砂岩型铀矿成矿的重要因素。
This paper provided petrography,LA-ICP-MS zircon U-Pb age,and zircon Hf isotopes of the Middle Jurassic sandstone in Hanshuiquan area,Santanghu Basin,eastern Junggar,analyses the source of clastic materials and its indication for sandstone-type uranium mineralization.Methods:Based on the field work,through the microscopic observation,the LA-ICP-MS zircon U-Pb isotopic chronology,and the LA-ICP-MS zircon Lu—Hf isotopes of malmstone.Result:The detrital zircon ages of the sandstone in the Middle Jurassic Xishanyao Formation are mainly distributed in the Late Paleozoic,and the peak ages of the two samples are 328 Ma and 340 Ma.The detrital zirconε_(Hf)(t)ranges from 8.9 to 14.7,and the two-stage model age ranges from 690 to 415 Ma.Detrital zircon ages from the sandstone in the Toutunhe Formation can be divided into three sections:238~163 Ma,505~259 Ma and 1950~744 Ma.Detrital zirconε_(Hf)(t)is-6.5~12.1,and the two-stage model age is between 1709~575 Ma.Conclusion:The Xishanyao Formation has a single source of material,mainly from the western Karamaili Maiqinwula and Yemaquan regions;the source of the Toutunhe Formation is relatively complex,and in addition to the detrital material from the Karamaili region,it also receives supply from other regions.The sudden change in age characteristics of detrital zircons between the two represents a severe tectonic deformation event in the Middle Jurassic of the East Junggar region.The source characteristics indicate that the uranium content in the Middle Jurassic strata in the Hanshuiquan area is relatively limited,and uranium source is an important factor limiting the mineralization of sandstone type uranium deposits in the area.
作者
刘珉
周玉
苏飞
袁彦伟
朱永胜
邢建磊
杨鱼帆
LIU Min;ZHOU Yu;SU Fei;YUAN Yanwei;ZHU Yongsheng;XINC Jianei;YANG Yufant(Urumqi Comprehensive Survey Center on Natural Resources,China Geological Survey,Urumqi830057;Innovation Base of Metallogenic Prediction and Prospecting in Central Asia Orogenic Belt,ChineseGeological Sociely,Urumqi830057;College of Earth Science,Chengdu Universily of Technology,Chengdu610059;Northwest Geological Exploration Institute of China Metallurgical Geology Administration,Xi'an710119)
出处
《地质论评》
CAS
CSCD
北大核心
2024年第2期742-758,共17页
Geological Review
基金
中国地质调查局项目(编号:DD20211550)
新疆维吾尔自治区自然科学基金面上项目(编号:2022D01A148)的成果。
