In order to prepare for the next in situ missions to Mars (MSL-2011 and ExoMars-2018), the objective of mythesis is to create a collection of relevant analogue rocks and minerals for calibrating and testing future (and existing) space flight instruments, in accordance with the geology of Mars. They were characterized using standard laboratory instrumentation (optical microscopy, Raman, IR, XRD, SEM, electron microprobe and ICP-MS), as well as by flight instrumentation in development (Mössbauer MIMOSII, ExoMars Raman and IR (MicrOmega) spectrometers). All the samples are described in an online database in the following web site: www.isar.cnrs-orleans.fr. A part of this thesis is dedicated to the development of a cathodoluminescence (CL) instrument that could potentially be adapted for space flight. Study of alteration processes of basalts on Earth that show some similarities to surface and subsurface processes occurring on Mars may help understand and interpret martian features. Therefore, to complete the collection, samples of hydrothermal and acidic weathered basalts were collected from the Skouriotissa mine in Cyprus. The mineralogical evolution of the basalt through different alteration facies was studied. Because terrestrial basalts are poorer in Fe and Mg than martian basalts, I synthesized two artificial martian basalts. The two artificial basalts are different in terms of cooling rate (~110°C/h and drop-quenched, >1200°C/h). Interestingly, the more slowly-cooled sample exhibits a spinifex texture, similar to that of komatiites. If similar basalts occur on Mars, such rocks when altered by aqueous processes may have astrobiological implications.
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:tel-00747608 |
| Date | 21 June 2012 |
| Creators | Bost, Nicolas |
| Publisher | Université d'Orléans |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | English |
| Detected Language | English |
| Type | PhD thesis |
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