西藏南部地热

GEOTHERMICS OF SOUTHERN TIBET

本文首先介绍了西藏南部花岗岩类岩石的热产率特点;其次根据在羊卓雍错和普莫雍错湖底观测的异常热流值(分别为146±17mW/m^2和91±5mW/m^2),探讨了西藏南部的大地热流,认为如此高的热流值是由高热产率的厚层花岗岩层产生的;最后对藏南的高热流和地热系统的分布进行了比较研究,根据它们分布空间的一致性认为在西藏南部地壳浅部存在异常热源,这些异常热源与区域高热流一起可能成为喜马拉雅地热带内众多地热系统的热源。

This paper covers three parts. The first one deals with the heat generation of granitoids in southern Tibet which varies with petrological characteristics. The terrestrial heat flow in southern Tibet is discussed in the second part. According to the anomalously high heat flows (146±17mW/m^2 and 91±5 mW/m^2) observed at the bottom of the Yamzhog Lake and Puma Lake respectively, they are produced by thick granites with high heat generation capacity. In the third part the distributions of the high heat flows and the geothermal systems are studied; the consistency of their spatial distributions suggests the existence of shallow crustal heat anomalies, which, together with the regional high heat flow, is probably the source for the geothermal systems within the Himalayan geothermal belt.