粤北下庄矿田竹筒尖铀矿床铀镭平衡系数特征探讨

Character of Uranium-Radium Equilibrium Coefficient in Zhutongjian Uranium Deposits of Xiazhuang Ore Field in Northern Guangdong

基于粤北下庄矿田竹筒尖铀矿床156个铀镭平衡系数样品,研究该地区铀镭平衡系数与铀含量、标高、岩性的变化关系,对这些变化关系进行综合整理分析,得出铀镭处于基本平衡略偏铀状态的分布特征。分析了铀镭平衡系数和铀含量之间的关系,当铀含量小于0.15%时,随着铀含量的逐渐增高,铀镭平衡系数减小,二者呈负相关关系;当铀含量大于0.15%时,铀镭平衡系数与铀含量的关系不明显。总结出铀镭平衡系数与标高的变化规律,由地表到深部,经历严重偏镭到偏铀再到基本平衡的过程。分析了铀镭平衡系数与硅化带、碎裂花岗岩、细粒黑云母花岗岩和中粒黑云母花岗岩的关系。上述成果为该地区物探编录和γ测井结果的准确计算、矿体边界的确定、铀矿资源量的估算提供了科学依据。

156 samples from Zhutongjian uranium deposits of Xiazhuang ore field were used to study the relation of uranium-radium equilibrium coefficient to uranium content, elevation and lithologic type in northern Guangdong. Relation analysis found that balance of uranium and radium are equilibrium or slightly to uranium. The equilibrium coefficient decreases with the increase of uranium content. If urani- um content is less than 0.15 %, the coefficient will decreased while uranium content increased; if urani- um content is higher than 0.15%, the relationship between uranium content is not obvious. From the surface to the depth, the uranium-radium equilibrium was strongly bias to radium, and then to uranium and relatively balanced. The relationship of equilibrium coefficient with silicification belt, fractured gran- ite, fine and medium grain biotite granite were studied to provide scientific basis for geophysical logging, correct calculation of gamma logging, ore body boundary determination and resources estimation.