江苏如东县小洋口地热田成因研究

地热资源按成因可分为对流型地热资源与传导型地热资源两大类。根据地热水的赋存介质差异，传导型地热资源又可分为松散岩类孔隙型、构造裂隙型及古构造面岩溶型3个亚类。小洋口地热田同时存在两种成因地热类型，深部断裂构造带地热水为对流型地热类型，其上部盐城组松散层中的地热水则是其伴生的传导型地热资源。其成因模式是，冷水沿金坛—如皋断裂在自身重力作用下下渗至4～5 km的深部并增温成为高温热水甚至蒸汽，由于密度的减小，其上浮返回浅部裂隙发育处并与其中温度相对较低的热水混合而降温，正由于温度和密度的变化为水的循环提供了动

Origin study of geothermal field in Xiaoyangkou of Rudong County in Jiangsu

Geoheat resource falls into two types of convection type and conduction type based on origin. Three sub-types of for conduc- tion type of geoheat resource based on varied storage medium,they were loose rocks type pore type,tectonic fissure type,and ancient structural surface karst. Xiaoyangkou Geoheat Field had two geothermal types,its deep fracture belt water was convection type,and the water in the upper loose sediments of Yancheng Formation was associated conduction type. The origin model was as follows: under the effect of self gravity,the cold water infiltrated into 4 m to 5 m deep well along Jintan to Rugao Fracture,and increased to high tempera- ture hot water or steam. Owing to the decrease of density,its floating returned to the shallow fissures and melted with low temperature warm water within the fissures,the variation of temperature and density provided power for the circulation of water.