粤东北贝岭地热田地热地质特征及水化学分析

Characteristics of Geothermal Geology and Hydrochemistry of the Beiling Geothermal Field in Northeastern Guangdong Province

粤东北地区拥有丰富的低温水热型地热资源。贝岭地热田位于河源深断裂北东端,具有优越的地热地质条件,地热田内施工的钻孔(ZK1~ZK5)均揭露到了热矿水,水温48.2~77.0℃。为了深入研究地热田内的水化学特征,通过运用系统的水文地球化学分析方法,得出研究区热矿水水化学类型为低矿化的HCO_(3)-Na型,SiO_(2)含量较高,可用作理疗矿泉水。研究区地下热矿水处于水岩作用的初级阶段,热矿水中的石英和玉髓溶解度已达平衡状态。使用石英温标进行热储估算,结果表明T_(石英)=116.0~150.1℃,平均地温梯度G=12.01℃/100 m,热储循环深度H=819.33~1103.26 m。本研究为今后该区的深部找热工作提供了一定的技术支撑。

Northeastern Guangdong is endowed with abundant low-temperature hydrothermal type geothermal resources.In this region,the Beiling geothermal field is located at the northeastern end of the Heyuan deep fault with superior geothermal geological conditions.The boreholes(ZK1~ZK5)drilled in the field have all revealed hot mineral water with temperature of 48.2~77.0℃.A systematic water chemistry analysis shows that the thermal mineral water in the study area is of the low-mineralized HCO_(3)-Na type with high SiO_(2) content,which can be used as physiotherapeutic mineral water.The subsurface thermal mineral water is in the primary stage of water-rock interaction and the solubility of quartz and chalcedony in the thermal mineral water has reached equilibrium.The results of thermal storage estimation using quartz temperature scale indicate T_(quartz)=116.0~150.1℃,the average ground temperature gradient G=12.01℃/100m,and the thermal storage circulation depth H=819.33~1103.26 m.These data provide a technical support for the development of geothermal resources in the study area in the future.