会东县新开田地区铀矿化特征及控制因素分析

新开田地区处在康滇地轴中段东缘,已发现冬瓜坪、坪街村、中梁子、大岩洞4个铀矿化点及众多异常点带。通过在该区开展专项地质测量、地面伽玛能谱测量、槽探及坑道揭露、样品分析等工作,并结合中梁子和坪街村典型铀矿化体分析了该区的铀矿化特征,发现中元古界黑山组和青龙山组炭质板岩、炭质千枚岩（平均铀含量7.5×10^-6~7.9×10^-6）是主要的赋矿层位,老街子断裂及其次级断裂是该区的控矿构造,硅化、绢云母化、绿泥石化等与矿化有关的热液蚀变发育。笔者认为新开田地区铀矿化受地层及岩性、构造、热液蚀变等的控制作用明显,老街子断裂与大马窑断裂挟持部位铀矿化信息丰富,存在良好的岩浆、构造、热液条件,为新开田地区最有利的成矿地段。

Mineralization characteristics of uranium deposits and the controlling factors in Xinkaitian, Huidong County

Xinkaitian area is located in the eastern margin of the central Kangdian Axis. Four uranium mineralization points in Dongguoping, Pingjie, Zhongliangzi and Dayandong, and a lot of abnormal points have been found.Special geological survey, ground gamma spectrometry survey, trough exploration and pit tunnel exposure, sample analysis and other work were carried out in this area, and in combination with typical uranium mineralization of Zhongliangzi and Pingjie village, the characteristics of uranium mineralization in this area were analyzed. The results show that the carbonaceous slate and carbonaceous phyllite in the Heishan formation and Qinglongshan formation are the main ore-bearing horizons(average uranium contentis 7.5×10^-6 to 7.9×10^-6);Laojiezi fault and its secondary faults are the controlling structure of the from area;the hydrothermal alteration related to mineralizationare developed, such as silicification, sericitization and chlorolization. The authors think that uranium mineralization is controlled by stratum and lithology,structure,hydrothermal alteration, and with the rich mineralization information in the zone between the Laojiezi fault and Damayao fault and good magmatic, tectonic and hydrothemal conditions, the area should be the most advantageous metallogenic section in Xinkaitian area and the key area for future prospecting.