棉花坑铀矿床地热水文地球化学条件及成因研究

Discussion on general situation and origin of geothermal water in Mianhuakeng uranium deposit

讨论了棉花坑铀矿床区域地质背景和主要地质构造格局,并通过对矿床深部地热钻孔涌水及含矿带附近的地表泉点、地表水的水化学分析研究,探讨了地热水形成的地质地球化学过程,指出棉花坑深部存在多方向构造的复合部位并赋存大量地热水,断裂构造利于热水的富集,并提供深部地下水补给通道,属中低温对流型地热系统;地热水补给来源为大气降水,受棉花坑断裂带控制,循环深度较深,与花岗岩热源层的能量交换充分,地热水具有水温稳定、水量大及承压的特点。

In this paper,the regional geological background and main geological structure pattern of Mianhuakeng uranium deposit were discussed at first.Then the hydrochemical feature of water gushing from geothermal boreholes in the deep part of the deposit,surface spring and surface water near the ore bearing belt was studied.The geological and geochemical forming process and genesis of geothermal water was summarized at final.It was pointed out that there are compound parts of multi-directional structures and a large amount of geothermal water in the deep part of Mianhuakeng deposit,The fault structure is conducive to the enrichment of hot water and provides deep groundwater recharge channel,which belongs to medium and low temperature convective geothermal system.The geothermal water supply source is atmospheric precipitation,which is controlled by the Mianhuakeng fault zone.The circulation is deep,and the energy exchange with the granite heat source layer is sufficient.The geothermal water has the characteristics of stable water temperature,large water volume and pressure.