准噶尔盆地南缘楼庄子地区头屯河组下段砂岩型铀成矿控制因素和成因分析  

Metallogenic Controlling Factors and Genetic Analysis of Sandstone Uranium Deposit in the Lower Member of Toutunhe Formation in Louzhuangzi Area,Southern Junggar Basin

作　　者：鲁克改[1] 杜默[1] 孙潇[1] 贾为卫 王守玉 LU Kegai;DU Mo;SUN Xiao;JIA Weiwei;WANG Shouyu(Geologic Party No.216,CNNC,Urumqi,Xinjiang 830011,China)

机构地区：[1]核工业二一六大队,新疆乌鲁木齐830011

出　　处：《铀矿地质》2023年第4期507-521,共15页Uranium Geology

基　　金：中核集团地勘费项目“新疆准噶尔盆地砂岩型铀矿综合编图与选区”(编号:202206-8);“新疆准噶尔盆地南缘金沟河-浅水河地区铀矿资源调查评价”(编号:202107-2)联合资助。

摘　　要：楼庄子地区位于准噶尔盆地南缘中段,区内铀矿化主要产于中侏罗统头屯河组下段。文章在研究沉积环境、构造演化、铀矿化特征的基础上,分析屯河组下段砂岩型铀矿的成矿环境、控制因素及成因类型。楼庄子地区铀矿化产于辫状河三角洲平原沉积,受控于自郝家沟凸起往西、北西方向发育的层间氧化带。多数地段强氧化亚带遭受剥蚀,地表出露弱氧化亚带,部分过渡带和翼部铀矿体已经剥蚀出地表。本区铀矿为层间氧化带砂岩型,含矿地层自晚侏罗世—早白垩世开始抬升剥蚀,接受含氧含铀水的补给,主要铀成矿期在晚白垩世—古新世期间,有43.8 Ma的成矿时长;铀成矿受辫状河三角洲平原、郝家沟凸起和晚白垩世-古新世红层期的控制,主要成矿作用在渐新世早期基本停滞,铀成矿停止年龄为(53±5)Ma,上新世之后部分氧化带和矿体遭受剥蚀,不排除叠加成矿的可能。Louzhuangzi area is located in the middle of the southern margin of the Junggar Basin and uranium mineralization was discovered in the lower member of Toutunhe Formation,Middle Jurassic.The article analyzed the uranium mineralization environment,control factors,and genetic types by studying its sedimentary environment,structural evolution,and uranium mineralization characteristics.Uranium mineralization occurred in the plains of the braided river delta,controlled by the interlayer oxidation zone that developed from the Haojiagou bulge to the west and northwest.Most of the strong oxide sub-zones have been eroded,left the weak oxide sub-belts in the surface,and some transition zones and wing uranium ore bodies been eroded out to the surface.Uranium mineralization in Louzhuangzi is of interlayer oxidation genesis,the ore-hosting strata have been uplifted and denuded since the Late Jurassic-Early Cretaceous,received replenishment of oxygen-containing uranium-containing water and formed the main uranium mineralization during the Late Cretaceous-Paleocene.The uranium mineralization is controlled by the sandstone of braided river delta plain,the Haojiagou bulge and the Late Cretaceous-Paleocene red strata.The main mineralization basically stagnated in the Early Oligocene,the age of uranium mineralization was(53±5)Ma,and some oxidation zones and ore bodies were eroded after the Pliocene,which did not rule out the possibility of superimposed mineralization.

关 键 词：楼庄子 头屯河组下段 层间氧化带 郝家沟凸起 

分 类 号：P619.14[天文地球—矿床学]