The Svartsengi High-Temperature Field, Iceland: Subsurface Geology and Alteration

Abstract

The geological succession of the Svartsengi high temperate field consists of lava successions with intervening hyaloclastite formations. About 20-40% of the succession below 800 m depth consists of intrusion. The reservoir aquifers are predominantly controlled by intrusive and some tectonic fractures/faults. The alteration pattern can be subdivided into distinct episodes where low temperature conditions are envisaged to have prevailed prior to high T condition. Two distinct episodes of high T activity are observed, where the latter one rises distinctly to higher elevation. The dominant alteration pattern conforms reasonably well to the present thermal regime in the Svartsengi high T field.