Abstract Southern Volcanic Zone (SVZ) hosts numerous thermal springs (25–85 °C), related to Liquine-Ofqui Fault System (LOFS) and Andean Transverse Faults (ATFs), suggesting the feasibility of low- to high-enthalpy geothermal exploitation. However, the local understanding of processes and factors controlling the high-temperature groundwater circulation remained undefined, which limits its exploitation. Following a brief review of SVZ, we address the previous issue by a hydrogeochemical and isotopic analysis of 15 thermal springs at Liquine area (representative of SVZ), supplemented by geochemical simulations. We demonstrate that fault zones and derived hydraulic properties have a predominant control on the ascending high-temperature groundwater circulation and hydrogeochemical processes. Spring discharges and outflowing temperatures are higher along the LOFS damage-zone and ATF than those along the LOFS fault core-zone. Albite dissolution is the main water-rock interaction that is enhanced by absorbed geothermal gases (H2S and CO2 in LOFS; CO2 in ATF). Trace element contents (Li, Rb, Cs, As, Mo) are influenced by hydraulic properties and geothermal gases within faults. Intrinsic hydraulic properties of fault zones, where damage-zone is more permeable than the core zone, affect the Li, Rb, Cs contents. While As and Mo solely differ according to the gases presence. Water stable isotopes point that steam heating processes enhance the hydrogeochemical reactions through the LOFS damage-zone and ATF, whereas only low-temperature processes occur through the LOFS core-zone. LOFS damage-zone and ATFs are great targets for the shallow geothermal resource exploitation. But simulations indicate an elevated risk of scaling with consequences on the operation plants due to silicate mineral precipitations. Finally, Liquine thermal springs provide interesting insights to respond to the current and future energy challenges in Central-South Chile.

中文翻译：

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探索智利南部火山带浅层地热资源：来自 Liquiñe 温泉的洞察

摘要 南部火山区 (SVZ) 拥有大量与 Liquine-Ofqui 断层系统 (LOFS) 和安第斯横向断层 (ATF) 相关的温泉 (25–85 °C)，表明低热焓地热开采的可行性。然而，当地对控制高温地下水循环的过程和因素的认识仍未明确，这限制了其开发。在简要回顾 SVZ 之后，我们通过对 Liquine 地区（代表 SVZ）的 15 个温泉进行水文地球化学和同位素分析，并辅以地球化学模拟来解决之前的问题。我们证明断层带和衍生的水力特性对上升的高温地下水循环和水文地球化学过程具有主要控制作用。沿 LOFS 损伤区和 ATF 的弹簧排放和流出温度高于沿 LOFS 断层核心区的排放和流出温度。钠长石溶解是主要的水-岩相互作用，被吸收的地热气体（LOFS 中的 H2S 和 CO2；ATF 中的 CO2）增强。微量元素含量（Li、Rb、Cs、As、Mo）受断层内水力特性和地热气体的影响。断裂带的固有水力特性，其中损伤带比核心带更具渗透性，会影响 Li、Rb、Cs 的含量。而 As 和 Mo 仅根据气体的存在而不同。水稳定同位素表明，蒸汽加热过程通过 LOFS 损伤区和 ATF 增强了水文地球化学反应，而只有低温过程通过 LOFS 核心区发生。LOFS损伤区和ATFs是浅层地热资源开发的重要目标。但模拟表明，由于硅酸盐矿物沉淀，结垢风险增加，对运行中的工厂造成影响。最后，Liquine 温泉为应对智利中南部当前和未来的能源挑战提供了有趣的见解。