摘要
通过对鄂尔多斯盆地镇原地区新发现的洛河组含铀砂岩样品中的酸解烃分析,初步研究了酸解烃中烃类气体组分特征,并进行成因和可能来源分析;在综合镇原地区铀成矿地质特征基础上,探讨了烃类流体对砂岩型铀成矿的作用。研究表明,镇原地区洛河组含铀砂岩中酸解烃气体组分以CH 4为主,为早三叠世延长组烃源岩生排烃产物。通过对其相关特征参数分析,认为含铀矿层中烃类气为有机成因的油型气,主要处于成熟高成熟阶段,是早期部分原油发生裂解形成的原油裂解气与干酪根初次裂解气。综合分析认为,该区砂岩型铀矿是深层还原性流体沿构造裂隙或顺层贯入洛河组早期红色砂岩中,形成蚀变分带现象,并在氧化还原过渡带形成铀矿(化)体,依此推测研究区内断裂发育处的氧化蚀变砂岩和灰色(灰白色或灰绿色)蚀变砂岩是重点找矿方向。
Acid hydrolysis of samples from the newly discovered U-bearing sandstone in Luohe formation is carried out and characteristics of composition of the hydrocarbons primarily studied and genesis and possible source analyzed.Geological characteristics of U deposits in zhenyuan area is summarised and the role of the hydrocarbon played on the sandstone type U mineralization primarily discussed.The hydrocarbon gas is dominated by CH 4,the product generated and expulsed from hydrocarbon source rock of Early Triassic Yanchang formation.Analysis of the relevant parameters shows that hydrocarbon gas of the U-bearing layer is genetically the oil type gas which was the early cracked crude oil and kerosene gas remaining at mature-high mature stage.We comprehensively analyze the factors and consider that reductive fluid penetrated along structural fissures and bedding plane into the early red sandstone of Luohe formation leaving alteration zoning and forming U ore(mineralization)bodies at transitional zone from oxidation to reduction thus U ore prospecting here should direct to fracture development areas,especially to the oxidation altered rock and gray(grey white or grey green)altered rocks.
作者
胡永兴
杨涛
胡妍
欧扬剑
李小强
HU Yongxing;YANG Tao;HU Yan;OU Yangjian;LI Xiaoqiang(Geological Survey of Gansu Province,Lanzhou 730030,China)
出处
《地质找矿论丛》
CAS
2023年第3期277-284,共8页
Contributions to Geology and Mineral Resources Research
基金
中国地质调查局项目“甘肃省鄂尔多斯盆地南缘泾川一带铀矿地质调查”(编号:DD20160128-06)
甘肃省科技重大专项“陇东地区砂岩型铀矿成矿规律研究”(编号:18ZD2GF019)
2020年陇原青年创新创业人才项目“陇东地区砂岩型铀矿成矿规律与找矿方向”
2020年甘肃省青年科技人才托举工程项目“陇东地区白垩系砂岩型铀矿成矿规律与战略选取研究”联合资助
关键词
烃类流体
砂岩型铀矿
洛河组
镇原地区
鄂尔多斯盆地
Hydrocarbon fluid
sandstone type U deposit
Luohe formation
Zhenyuan area
Ordos basin
