From hyperalkaline mineral waters towards a Mars analogue. Cabeço de Vide

In this paper we improve knowledge on the Cabeço de Vide (Portugal) spring and borehole mineral waters issuing at the contact metamorphism zone developed by the Alter-do-Chão mafic/ultramafic pluton (of Ordovician age) on the surrounding Cambrian limestone rocks. The dominant microorganisms found in the Cabeço de Vide mineral waters (AC3 borehole) were affiliated to Hydrogenophaga and Serpentinomonas, which are well-known hydrogen oxydizing bacteria.