松辽盆地南部DL铀矿床姚家组下段地球化学特征与铀矿化的关系

Geochemical Characteristics of Sandstone of the Lower Yaojia Formation in DL Deposit and Their Relation to Uranium Mineralization,Southern Songliao Basin

为深入探究地球化学特征与铀矿化的关系,以松辽盆地南部DL铀矿床为研究对象,对姚家组下段各亚带砂体地化环境和微量铀钍系统取样,分析地球化学元素特征及铀富集规律。研究表明,当岩体Fe^(3+)/Fe^(2+)值为1.0~1.5和C有机含量为0.15%~0.25%时发现铀相对富集,且氧化带对矿体控制明显,整体表现为第一亚层底部氧化带铀迁出率较高,Ⅰ号矿体靠近底部氧化带上翼发育,而Ⅱ号矿体则靠近第二亚层顶部氧化带下翼发育。说明Ⅲ号矿体形成于同生沉积预富集作用,而Ⅰ、Ⅱ号矿体为流体混合改造作用叠加成矿。

In order to further explore the relationship between geochemical characteristics and uranium mineralization,the DL uranium deposit in the southern Songliao basin are taken as the research object,the sand bodies in the Lower Yaojia Formation are sampled,and the geochemical element characteristics and uranium enrichment rule are analyzed.When the Fe^(3+)/Fe^(2+)values of the rock mass range from 1.0 to 1.5 and the C org content ranges from 0.15%to 0.25%,it is found that uranium is relatively enriched,and the oxidation zone obviously controls the ore bodies.The uranium migration rate of the oxidation zone at the bottom of the first sublayer is higher.The No.Ⅰore body develops near the upper wing of the bottom oxidation zone,while the No.Ⅱore body develops near the lower wing of the oxidation zone at the top of the second sublayer.It is further indicated that No.Ⅲore body is formed by syngenetic sedimentary preenrichment,while No.Ⅰand No.Ⅱore bodies are formed by fluid mixing transformation superposition.