从青海共和—贵德盆地与山地地温场特征探讨热源机制和地热系统

青海共和—贵德盆地及其相间山地具有盆地传导型地热资源,地温梯度大,地热勘探钻孔在基底均见花岗岩,盆缘山地隆起断裂对流型温泉呈带分布,水温高,也出露在花岗岩中.对其热源机制的认识目前存在分歧.本文对地幔型热源提出质疑,认为花岗岩放射性生热为壳内热源并提出地化依据;同时,用地热钻孔测温曲线和地球化学地热温标对热储温度和深度进行了探讨.研究结果表明,周边山地属中温地热系统,新生代断陷盆地内具高温地热系统,其钻孔井底测温已达175~180℃,是干热岩开发的优选地段.

A discussion on the heat source mechanism and geothermal system of Gonghe-Guide basin and mountain geothermal field in Qinghai Province

Gonghe-Guide basin and its alternate mountains have characteristics of large basin conduction type geothermal resources geothermal gradient,existence of granite in geothermal drilling basement at several places,and zonal distribution of basin edge mountain uplift-fracture-convection type hot springs with high water temperature.At present,there are controversies concerning heat mechanism.The authors query the argument of the mantle type heat source,and hold that the granite radioactive heat is the geochemical basis of the earth's crust internal heat source.In addition,the authors use geothermal drilling temperature measurement curve and geochemical geothermometer to predict geothermal reservoir temperature and depth.It is held that this is a meso-low temperature system.Finally,the geothermal gradient calculation problems and geothermal system are discussed.