Geothermal Resource Indications of the Geologic Development and Hydrothermal Activities of D.R.C.

Abstract

Published sources report the occurrence of more than 135 thermal springs in D.R.C. All occur in the eastern part of the country, in association with the Western rift and the associated rifted and faulted terrains lying to its west. Limited information was available on the characteristics of the thermal features and the natural conditions under which they occur. Literature study of the regional distribution of these features and of the few relatively better known thermal spring areas, coupled with the evaluation of the gross geologic conditions yielded encouraging results. The occurrence of the anomalously large number of thermal springs is attributed to the prevalence of abnormally high temperature conditions in the upper crust induced by a particularly high standing region of anomalously hot asthenosphere. Among the 29 thermal springs the locations of which could be determined, eight higher temperature features which occur in six geologic environments were found to warrant further investigation. The thermal springs occur in all geologic terrains. Thermal fluid ascent from depth is generally influenced by faulting while its emergence at the surface is controlled by the near-surface hydrology. These factors allow the adoption of simple hydrothermal fluid circulation models which can guide exploration. Field observations and thermal water sampling for chemical analyses are recommended for acquiring the data which will allow the selection of the most promising prospects for detailed, integrated multidisciplinary exploration. An order of priorities is suggested based on economic and technical criteria.