Santorini volcano as a potential Martian analogue: The Balos Cove Basalts

Pantazidis A, Baziotis I, Solomonidou A, Manoutsoglou E, Palles D, Kamitsos E, Karageorgis A, Profitiliotis G, Kondoyanni M, Klemme S, Berndt J, Ming D, Asimow PD

Research article (journal)

Abstract

The interpretation of geologic processes on Mars from sparse meteorite, remote sensing and rover data is influencedby knowledge gained from well-characterized terrestrial analogues. This calls for detailed study ofcandidate terrestrial analogues and comparison of their observable features to those encountered on the surfaceof Mars. We evaluated the mineralogical, geochemical, and physical properties of the Balos cove basalts (BCB)from the island of Santorini and compared them to Martian meteorites, Mars rover surface measurements, andother verified Martian analogues obtained from the International Space Analogue Rockstore (ISAR). Twenty rocksamples were collected from the Balos cove area based on their freshness, integrity, and basaltic appearance inthe field. Optical microscopy of BCB revealed a pilotaxitic to trachytic texture, with olivine and clinopyroxenephenocrysts in a fine groundmass of olivine, clinopyroxene, plagioclase, magnetite, and devitrified glass. Allmajor minerals show normal zoning, including calcic plagioclase (An78–85 at the core and An60–76 at the rim),augite (En36-48Wo41-44Fs11–21), and olivine (Fo74–88). The dominant bands in the infrared-attenuated total reflectance(IR-ATR) spectra from BCB can be assigned to olivine (~875 cm−1), calcic plagioclase (~1130 cm−1),and augite (~970 cm−1). The whole-rock chemical compositions and mineralogy of the BCB are similar topublished analyses of typical olivine-phyric shergottites and basalts and basaltic materials analyzed in Gusev andGale craters on Mars. BCB porosity is in the range of 7–15% and is similar to the porosities of the ISAR samples.Although no terrestrial rock is ever a perfect match to Martian compositions, the differences in mineralogy andgeochemistry between BCB and some classes of Martian samples are relatively subtle and the basalts of Santoriniare as close a match as other accepted Mars basalt analogues. The Santorini site offers excellent field logisticsthat, together with the petrology of the outcrop, makes it a valuable locality for testing and calibration deployments,field training, and other activities related to current and future Mars exploration.

Details zur Publikation

Release year: 2019
Language in which the publication is written: English