Source Models for the TVZ Geothermal Fields

Abstract

This paper presents results from large scale two and three dimensional hydrological models of the geothermal fields. Two heat source concepts for the geothermal fields are presented - the ëhot plateí model, where the heat sourceis constant both spatially and in time, and the ëcoolingintrusiveímodel, where a body of hot rock is cooled by circulatingground water. The of large scale topographyon the hydrologyof the is explored. Topographicallydrivenheat flows stronglyinfluence the development of the hydrothermal systems. Where multiple intrusions occur, heat and mass flows new plutons are channelled preferentially into regions where remnant heat from old plutons remains. This mechanism can accountfor the stable positions of the geothermal fields over periods much longer than the coolingtime for an individual pluton.