Secondary Mineralogy of the Olkelduhals Hydrothermal System: Applications to Past Mars Environments

Autumn Routson, “Secondary Mineralogy of the Olkelduhals Hydrothermal System: Applications to Past Mars Environments”
Mentors: Lindsay McHenry & Jordan Ludyan, Geosciences

Opaline and amorphous silica, sulfate-rich soils, and Fe-oxides in association with volcanic materials observed by the MER Spirit rover near Home Plate, Gusev crater have been interpreted as evidence of hydrothermal activity on Mars. To better constrain the processes that form secondary minerals in hydrothermal environments, our studies are focused on the Olkelduhals hydrothermal area, Iceland. Geochemical analysis of hydrothermally altered sediment samples from Olkelduhals indicates the acidic alteration has caused the concentration of immobile silica and titanium to become enriched in the alteration products. More mobile phases such as sodium and potassium oxides have been leached out of the system. Each sample’s bulk mineralogy was determined by X-Ray Diffraction (XRD). In order to detect the major, minor, and trace oxides, the samples were analyzed using X-Ray Fluorescence (XRF). The resulting dominant minerals include pyrite, amorphous silica, and clays such as montmorillonite and kaolinite. The high silica and titanium content found at Olkelduhals is similar to that which is found at Gusev crater, Mars, allowing for the comparison of the processes which produce these secondary minerals.

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  1. Nice work, Autumn! I like how you separated the samples by location in the XRD table- it makes the context nice and clear.

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