Characterization of an exhumed high-temperature hydrothermal system and its application for deep geothermal exploration: An example from Terre-de-Haut Island (Guadeloupe archipelago, Lesser Antilles volcanic arc)

Description

We present integrated structural, petrological, mineralogical and geochemical investigations conducted on an ex-humed hydrothermal system identified in Terre-de-Haut Island (Guadeloupe archipelago). This work demon-strates, for the first time, the occurrence of ductile shear zones, marked by the development of spacedschistosity planes generated by pressure-solution processes. We unravel first that the development of spacedschistosity is coeval with high-temperature hydrothermalism (approximately 350 °C) and second that this hy-drothermal alteration occurred at a depth of less than 2 km. We highlight, at shallow crustal depths, the recordof both vertical and lateral fluid pathways in the studied volcanic arc. Finally, combining this new dataset withthe large number of published surface data obtained in the active geothermal system of Bouillante, we proposea conceptual scheme for the studied fossil reservoir to document the roots of magmatic arc-related active geo-thermal systems and to introduce new perspectives for deep geothermal exploration.

Abstract

International audience

Additional details