胶东地热田地热流体的补径排特征——以招远东汤地热田为例

Recharge Runoff and Discharge Characteristics of Geothermal Fluid of Jiaodong Geothermal Fields—Setting Dongtang Geothermal Field in Zhaoyuan City as an Example

摘要:

招远东汤地热田是胶东现有16处天然温泉典型之一，以东汤地热田为例，剖析胶东地热田的补径排特征，对胶东各地热田的资源评价及开发利用具有重要的现实意义。该文通过地热地质条件综合分析、地热流体与基岩水及第四系水水化学成分对比、D，18O同位素分析、模型概化等手段综合研究，认为东汤地热田主要受招平断裂带与玲珑断裂带的控制，其复合部位为地热流体入渗、深循环的主径流通道。地热流体的Cl，F，Ba2+，Li，Sr2+，H2SiO3等离子及TDS含量明显高于其周边的水体，且随第四系水、基岩水及地热流体埋藏深度的增加，其δD与δ18O值逐渐偏负，确定地热流体与其周边的水体并无水力联系；通过地热流体D，18O同位素与大气降雨线的关系，得出地热流体补给来源于大气降雨。由D同位素高程效应，算得地热流体补给高程为314～414m左右，结合招平断裂与玲珑断裂的复合部位延伸方向，确定地热田的主要补给区为距离地热田东北方向15km的双顶山山区。该文补径排特征的研究，对胶东其他天然温泉的补径排特征及补给区的研究具有一定的借鉴意义。

Abstract:

Dongtang geothermal field is one of 16 typical natural hot springs in Jiaodong area. Setting Dongtang geothermal field as an example, characteristics of recharge, runoff and discharge of Jiaodong geothermal fields has important practical significance for evaluation and development of geothermal resources. In this paper, based on comprehensive analysis of geothermal geological conditions, the comparison of chemical components of geothermal fluid, bedrock water and quaternary water,δD and δ18O isotopic analysis and model generalization, it is concluded that Dongtang geothermal field is mainly controlled by Zhaoping fault and Linglong fault. Its composite parts is main runoff channels for geothermal fluid infiltration and deep cycle. The contents of Cl, F, Ba2+, Li, Sr2+, H2SiO3 and TDS of geothermal fluid are significantly higher than its surrounding water. Accompanying with the increase of the depth of Quaternary water and bedrock water, the value of δD and δ18O is gradually negative. It is showed that there is no hydraulic connection between geothermal fluid and its surrounding waters. Through the relationship between D and 18O isotopes of geothermal fluid and atmospheric rainfall line, it is concluded that recharge of geothermal fluid is derived from atmospheric rainfall. D isotope elevation effect shows that geothermal fluid recharge altitude is about 314～414m. Combining with the extending direction of the connection parts of Zhaoping fault and Linglong fault, it is determined that main recharge area of the geothermal field is located in Shuangdingshan mountain area, which is 15km northeast of the geothermal field. The study of the characteristics of recharge, runoff and discharge has a certain reference significance for the study of the recharge, runoff and discharge characteristics of other natural hot springs in Jiaodong area.