Heat-producing granitoids of North Pakistan as potential geothermal prospects

巴基斯坦北部的喜马拉雅山脉暴露出大量和部分体积巨大的富含放射成因元素的花岗岩类岩石。在该地区的地表热流升高已部分归因于浅生产的放射性热在这些岩石中，与快速折返和潜在的摩擦/应变加热。我们的目的是探索放射性热生产的作用，通过采样的一系列典型的岩性，并确定其放射性核素含量和其他地球化学参数。所获得的数据将用于数值模型。设计这些模型是为了测试花岗岩类的放射成因含量、形状和体积的变化与背景热通量对浅层（下至几公里）地下和温泉沃茨温度的影响。在第一次采样活动和放射性含量的初步分析的基础上，我们假设，大体积的花岗岩和片麻岩的放射性核素浓度较低，可能是更好的地热勘探目标比小，强烈富集的浅色花岗岩和伟晶岩。更好地了解巴基斯坦北部地质框架的地热潜力可能会使生活在这些偏远地区的社区受益。

The Himalayas of North Pakistan expose numerous and in part voluminous granitoid rocks enriched in radiogenic elements. Elevated surface heat flow in the region has been attributed in part to shallow production of radiogenic heat in these rocks, in concert with rapid exhumation and potentially frictional/strain heating. We aim to explore the role of radiogenic heat production by sampling a range of typical lithologies and determining their radiogenic nuclide contents and other geochemical parameters. The data obtained will be used in numerical models. These models are designed to test the effect of variations in radiogenic content, shapes and volumes of granitoids versus background heat flux on temperatures of the shallow (down to a few km) subsurface and of hot spring waters. On the basis of a first sampling campaign and preliminary analyses of radiogenic contents we hypothesize that large-volume granitoids and gneisses with somewhat lower concentrations of radiogenic nuclides may be better targets for geothermal exploration than small, strongly enriched leucogranites and pegmatites. Improved understanding of the geothermal potential as a function of the geological framework in North Pakistan may benefit communities living in these remote regions.