Calculated by using the pipeline model, the burial depths of the 150 and 180°C hot dry rocks (HDRs) are 3.20–3.56 and 3.92–4.36 km in the Reshuiwei geothermal field, respectively, while those in the Huitang geothermal field are 3.13–3.50 and 3.84–4.28 km, respectively. Based on the analysis of the geophysical and terrestrial heat flow data, rock thermal generation rates, and the hydrochemical thermometric scale data, we summarized the formation mechanisms of the HDRs in Hunan Province: (i) the boundary deep faults in the welding area have made the intersection part of the deep faults an open tectonic environment, which is beneficial to the upwelling of deep-mantle-sourced thermal matter. (ii) The southeastern Hunan Province is the front region of the West Pacific subduction and retreat. Lithospheric thinning in this area is significant since the Mesozoic era, especially in the Dongting Lake basin, which was formed during extension and depression. This kind of regional lithospheric thinning is favorable for the lateral and upward migration and the intrusion of the deep-mantle-sourced hot substances. (iii) Rocks with high radioactive heat production rates are important crustal thermal sources for the formation of HDRs. Besides that, plutons with similar geological conditions are favorable for the formation of HDR resources. These plutons include the Baimashan pluton and its surrounding areas, and the eastern Dongting Lake plain. Moreover, the intermediate and acid granites distributed in the Chenzhou-Linwu deep fault are also part of the plutons, and the area where the Chenzhou-Linwu deep fault convergent with the Changde-Anren deep fault.

中文翻译：

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湖南省典型干热岩的形成机制

利用管道模型计算，热水围地热田150℃和180℃干热岩（HDRs）埋深分别为3.20~3.56和3.92~4.36 km，灰塘地热田为3.13~分别为 3.50 和 3.84–4.28 公里。基于地球物理和大地热流数据、岩石热生成速率和水化学测温尺度数据的分析，我们总结了湖南省 HDRs 的形成机制：（i）焊接区的边界深断层使深部断裂交汇处为开阔的构造环境，有利于深部地幔源热物质的上涌。(ii) 湖南省东南部是西太平洋俯冲后撤的前沿地区。该区岩石圈自中生代以来减薄显着，尤其是洞庭湖盆地，是在拉张和坳陷过程中形成的。这种区域性岩石圈减薄有利于深部地幔源热物质的横向向上运移和侵入。(iii) 具有高放射性产热率的岩石是形成 HDR 的重要地壳热源。此外，地质条件相似的深成岩有利于HDR资源的形成。这些岩体包括白马山岩体及其周边地区和东洞庭湖平原。此外，陈州-临武深断裂中分布的中酸性花岗岩也是岩体的一部分，