Bizkaiko itsaspeko sumendiaren analisi geokimikoa

Abstract

Evidence of geomorphology traces of past liquid water on the surface of Mars suggests that this planet once had habitable conditions and leads to question about life. To investigate that, ESA and NASA space explorations organizations will send two rovers. For this reason, the necessity for the proper understanding and interpretation of the results obtained implies the study of terrestrial Martian analogues. In this work, Armintza, the Cretaceous alkaline submarine volcano outcrop has been studied and proposed as a Martian analogue. The samples were geochemically characterizes by Raman and Vis-NIR spectroscopies, considering that they are the two techniques that will go on-board the rovers of the next planetary missions. As was expected, silicates (phyllosilicates) were the major minerals but also compounds such as carbonates, sulphates and oxides could be detected. Phyllosilicates have special importance because they are indicators of aqueous weathering processes of primary magmatic rocks and they need liquid water for their formation. In addition, these compounds have been reported to be present in the Mars surface, specifically in Oxia Planum, the landing site for the Exomars2020 rover of the ESA mission as well as in Jezero crater, the landing site for the Mars 2020 rover of the NASA mission.; Marteko iraganeko lurzoruan agerian utzitako ur-likidoaren aztarna geomorfologikoak noizbait izandako bizigarritasun-baldintzetara aditzera ematen du eta honek, bizitzari buruzko galderak egitera. Horretarako 2020. urtean ESA-k eta NASA-k Martera ibilgailu robotiko bana bidaliko dute. Beraz, lortutako emaitzak ulertzeko eta interpretatzeko lurreko analogoen ikerketak egitea garrantzitsua da. Ikerketa lan honetan, Armintza, Kretazeo garaian gertatutako izaera alkalinodun itsaspeko sumendiaren ondoriozko azaleratzea Marteko analogo gisa proposatu da. Laginen ikerketa geokimikoa egiteko hurrengo Marteko misioetan erabiliko diren Raman eta Vis-NIR espektroskopia teknikak erabili dira. Espero zen bezala konposatu nagusienak silikatoak (filosilikatoak) dira, hala ere, karbonatoak, sulfatoak eta oxidoak ere karakterizatu dira. Filosilikatoek garrantzi handia dute lehen mailako arroka magmatikoen meteorizazio prozesuen adierazleak direlako eta ura beharrezkoa dutelako haien eraketetarako. Gainera, filosilikatoak Marten aurkitu dira, bereziki Oxia Planumen, ESA-ren Marteko ExoMars 2020 misioaren lurreratze tokia baita Jezero kraterrean ere, NASA-ren Mars 2020 misioaren lurreratze tokia.