Study of a terrestrial Martian analogue: Geochemical characterization of the Meñakoz outcrops (Biscay, Spain)

Abstract

The necessity to create databases for the proper interpretation of the results obtained by the rovers that will be sent by ESA to Mars implies the study of terrestrial Martian analogues. In this work, the Meñakoz outcrops, which are basaltic volcanic rocks interbedded with Turonian sediments coming from a Cretaceous submarine volcano outcrop located in Biscay (northern Spain), have been studied and proposed as a Martian analogue. Considering that Raman and near infrared spectroscopies are two of the techniques that will go on‐board the rovers in the next planetary missions, they were used to characterize the samples collected in Meñakoz. As was expected, silicates (phyllosilicates) were the major minerals detected by those techniques in the Meñakoz samples, but also, compounds such as sulfates and oxides could be detected. Phyllosilicates are very important because they are some of the compounds that have been reported to be present on the Mars surface in previous missions and specifically in Oxia Planum, the landing site for the ExoMars 2020 rover of the ESA missions to Mars. This fact provides reasons to propose the emplacement of Meñakoz as Martian analogue.

Raman spectroscopic peculiarities of Icelandic poorly crystalline minerals and their implications for Mars exploration

“…Going back to Ruiz-Galende et al . 45 , in their samples from Meñakoz outcrop, they also found anatase which formation was suggested to be abiotic from the alteration of titanium‐rich minerals by hydrothermalism. They reported distribution patterns of the three anatase-characteristic peaks similar to those observed here for the N-IF-2 sample and associated by Glamoclija et al .…”

“…Ruiz-Galende et al . 45 studied samples from the Meñakoz outcrop, claiming the zone as a good Martian analogue. They measured hematite with the same band at 660 cm −1 that they also explained by asymmetries of the crystal structure caused by impurities in agreement with 44 .…”

GeoRaman

“…The identification of the hydration states of minerals species is very important in the exploration of Mars: Shi et al [16] studied the spectral features related to different magnesium chloride hydrates by means of Raman, midinfrared (MIR), visible near-infrared (VNIR) and near-infrared (NIR) spectroscopies. Ruiz-Galende et al [17] investigated a volcanic outcrop, Meñako, Biscay, Spain, proposed as a Mar analogue setting, by Raman spectroscopy and visible near-infrared spectroscopy to gain a better understanding of spectral signatures likely obtained on the upcoming ExoMars and NASA 2020 Martian rover missions. Malherbe et al [18] compared Raman spectra obtained from geological matrixes, containing silicate, sulfate and carbonate minerals and elemental sulfurs, with a field portable and benchtop Raman instruments.…”

Characterization of olivines and their metallic composition: Raman spectroscopy could provide an accurate solution for the active and future Mars missions

“…[4] In fact, the forsterite (Fo) content is an important compositional indicator, and is widely used to identify primary mantle-derived melts, assess the degree of evolution experienced by magmas, and estimate magma crystallization and mantle potential temperatures. [9] As is described in the literature, [10] olivine can undergo different weathering processes depending on its location, especially if there is water present in the surroundings. The Mg content in the olivine bolsters its resistance to chemical weathering and lowers its kinetic dissolution rate.…”

“…All these facts lead to different weathering paths, [13] resulting in the formation of different secondary minerals, such as iddingsite (a combination of clay minerals, iron oxides, and ferrihydrite). [10] Olivine also takes part in weathering processes such as low-temperature aqueous alteration (e.g., olivine replacement by clays) and higher-temperature aqueous alteration (e.g., serpentinization of olivine). [13] The fact that olivine weathers easily depending on the environmental conditions may prove to be more of an advantage than a disadvantage in space exploration.…”