Geochemical characterization of the Martian analogues Enekuri and Fruiz, located in the Basque-Cantabrian Basin, by spectroscopic techniques.

This work presents the geochemical characterization of two Martian analogues located in the Basque-Cantabrian Basin: Enekuri and Fruiz. In contrast to previous works carried out on the coastline analogues Meñakoz and Armintza (Biscay, Spain), these new outcrops are not in contact with sea-water nowadays. Hence, the weathering processes observed in Enekuri and Fruiz (inland) are different from those observed in Armintza and Meñakoz (coastline). In this way, among all the mineral phases found the only ones in common between inland and coastline outcrops are albite and chlorites, minerals that were formed in aqueous conditions. Understanding the differences presented in both types of outcrops could help to interpret the future results from the missions Mars2020 and the ExoMars2022, since coastline outcrops are affected by sea-water weathering and inland outcrops are altered by the high biological activity.