| Popis: |
The granitoids widely distributed in South China are characterized by multi-stage evolution via episodic intrusions, in a complex geodynamic setting. Since granites have high radioactive heat generation and excellent thermal conductivity, a deep moderate- to high-temperature geothermal system can be formed in the presence of high-quality, fissured granite geothermal reservoirs and thermal insulation with appropriate cap rocks. The key to exploring deep geothermal resources is to identify high-quality fissured granite geothermal reservoirs of a certain scale in a thermal anomaly zone with high background heat-flow values. To determine the controlling effects of the distribution and development characteristics of granite geothermal reservoirs on the generation and enrichment of deep geothermal resources, this study analyzed the characteristics of the geothermal reservoirs in the Huangshadong geothermal field in the Yuezhong Depression, Guangdong Province, and their controlling effects on the formation of geothermal resources. The results are as follows. The hydrothermal system in the Huangshadong geothermal field mainly distributed in the contact zones between magmatic plutons and surrounding rocks, is significantly controlled by faults, followed by neoid volcanic apparatus and magmatic activities. That is, the geothermal system therein is under joint control of structures and magmas. Moreover, fractured zones of neoid transtensional faults conduct the geothermal water in the hydrothermal system and control its shallow discharge. Therefore, the hydrothermal system in the study area is characterized by the control of transpressional tectonic zone and volcanic apparatus, and geothermal water conduction through fractured zones of transtensional faults. |
