酒东盆地红山地区下白垩统含铀目的层黏土矿物研究

Study on the clay mineral in uranium-bearing target strata of Lower Cretaceous in Hongshan area,Jiudong basin

对酒东盆地红山地区下白垩统含铀目的层中黏土矿物进行扫描电镜(SEM)、X射线衍射(XRD)、X射线能谱(EDX)等的系统研究,结果表明:含铀目的层碎屑岩的源岩主要是碱交代的酸性岩浆岩,其黏土矿物类型主要为高岭石,其次为绿泥石。高岭石既有陆源高岭石,也有自生(蚀变)高岭石;高岭石化带(浅色带)可以作为该区铀矿找矿的主要标志层,其厚度和蚀变强度等可以作为判断该区铀矿富集程度的依据之一。绿泥石主要为自生绿泥石,与高岭石形成于不同时期,可能是由高岭石转化而成。黏土矿物研究显示,该区自白垩纪以来经历了由温暖潮湿气候逐渐向干旱气候转变的过程。

The clay mineral in uranium-bearing target strata of Lower Cretaceous in Hongshan area of Jiudong basin have been studied by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,X-ray spectroscopy（EDX）and etc.The clay mineral is found mainly kaolinite,followed by chlorite.The source rocks of clastic rocks in target layer are mostly acidic magmatic rocks with alkaline metasomatism.The sources of kaolinite include both land-based source and the authigenic（alteration）;the alteration belt of kaolinization（light colour zone）can be used as mainly criterion layer for prospecting uranium deposits in Hongshan area,and its thickness and intensity can be used as one of the evidence to judge the extent of uranium enrichment.The chlorite is mostly self-chlorite which was formed at different times to that of kaolinite and might be turned from the kaolinite.The study of clay minerals show that the weather in this area has experienced a gradual change from warm and humid to dry environent since Lower Cretaceous.