干热岩控热构造系统厘定与类型划分

Classification and Determination of Thermal Control Structural System of Hot Dry Rock

为了研究干热岩成因机理,综合分析了干热岩形成背景、控热构造系统及尺度.地球中的干热岩具有特殊的形成构造背景,控热构造对干热岩热能的传输与聚敛具有很重要的作用,导致岩石圈不同热结构和热异常.控热构造可划分为生热、导热、储热和释热构造.生热构造包括地幔软流圈底辟,具有大量高放射性元素的岩浆房,活动性的深大断裂等;中、下地壳脆韧性转换带,活动的韧性剪切带是导热构造;中、下地壳的低阻高导体,韧性剪切流变层既是导热层,也是储热构造;火山、地震、浅表层次的活动断裂等为释热构造;控热构造的类型受到构造尺度和构造背景的限定.由于地壳中控热构造分布状态及发育特征差异较大,从而导致干热岩等地热能资源在地壳中的埋深、规模、热量以及分布状态等也有较大差异.

In order to study the genetic mechanism of hot dry rock(HDR),the formation background,thermal control structure system and scale of HDR are comprehensively analyzed in this paper.The distribution of HDR in the earth is not ubiquitous,but has its special tectonic background.The thermal controlling structure system plays a very important role in the transmission and accumulation of heat energy of HDR and causes different anomalies in the lithosphere.The thermal controlling structures can be further divided into four basic types:heat generating structure,heat conducting structure,heat storage structure and heat releasing structure.Heat generating structures include mantle asthenosphere diapir,magma chamber with large amount of high radioactive elements,active deep faults and so on.The brittle-ductile transitional zone in the middle and lower crust and the active ductile shear zone are thermal conductive structures.The ductile shear rheological layer is the heat conduction layer and the heat storage structure.Volcanoes,earthquakes,shallow active faults are heat releasing structures.The types of thermal control structure are limited by structural scale and tectonic setting.Due to the great differences in the distribution and development characteristics of heat controlling structures in the crust,the buried depth,scale,capacity and distribution state of geothermal energy such as hot dry rocks in the crust are also quite different.