广西干热岩地热资源赋存条件分析

基于以往的认识,广西属于“缺煤、少油、乏气”的能源资源匮乏区,绝大部分能源靠进口或外省输送,能源结构极不合理。但是,广西地处亚欧板块、印度板块与太平洋板块的交接地带,地壳厚度较薄,断裂构造发育,岩浆岩大面积出露且放射性元素含量较高,具有较好的生热、储热条件。基于EGM2008全球超高阶地球重力场模型对广西地壳结构和深部界面重新计算,综合前期基础地质调查资料、元素地球化学资料、地热地质资料,对广西干热岩的成生条件和保存条件进行分析,认为北部湾盆地、玉林凹陷、郁江凹陷等构造单元具有干热岩成藏条件,可作为广西干热岩远景调查区进行下一步勘查。

Analysis on the occurrence condition of geothermal resources of hot dry rock in Guangxi

Conventional wisdom has long regarded Guangxi as a resources-poor region for its lack of coal, oil and gas resources. Indeed, Guangxi has an extremely unsustainable energy structure with most energy imported from other provinces or foreign countries. However, Guangxi is located at the intersections of the Eurasian, Indian and Pacific plates, thus has relatively thin crust, well developed fault system and large volcanic rock outcrops with high radioactive elemental content. In fact, southeast Guangxi has good heat generation and storage conditions. Based on the Earth Gravitational Model 2008 (EGM2008), we recalculated the crustal structure and crystalline basement interface in Guangxi using Parker-Oldenburg’s algorithm. We analyzed the conditions for dry hot rock formation by integrating previous basic geological survey and elemental geochemical and geothermal geological data. We concluded that dry hot rock formation conditions are met in the Beibu gulf Basin and Yulin and Yujiang Depressions. These areas can be used for hot dry rock prospective survey in the next exploration.