Amazonian volcanism inside Valles Marineris on Mars

0475545 - GFÚ 2018 RIV NL eng J - Journal Article
Brož, Petr - Hauber, E. - Wray, J. J. - Michael, G.
Amazonian volcanism inside Valles Marineris on Mars.
Earth and Planetary Science Letters. Roč. 473, September (2017), s. 122-130. ISSN 0012-821X. E-ISSN 1385-013X
Institutional support: RVO:67985530
Keywords : Mars * Valles Marineris * volcanism * scoria cone * hydrothermal activity
OECD category: Volcanology
Impact factor: 4.581, year: 2017

The giant trough system of Valles Marineris is one of the most spectacular landforms on Mars, yet its origin is still unclear. Although often referred to as a rift, it also shows some characteristics that are indicative of collapse processes. For decades, one of the major open questions was whether volcanism was active inside the Valles Marineris. Here we present evidence for a volcanic field on the floor of the deepest trough of Valles Marineris, Coprates Chasma. More than 130 individual edifices resemble scoria and tuff cones, and are associated with units that are interpreted as lava flows. Crater counts indicate that the volcanic field was emplaced sometime between similar to 0.4 Ga and similar to 0.2 Ga. The spatial distribution of the cones displays a control by trough-parallel subsurface structures, suggesting magma ascent in feeder dikes along trough-bounding normal faults. Spectral data reveal an opaline-silica-rich unit associated with at least one of the cones, indicative of hydrothermal processes. Our results point to magma-water interaction, an environment of astrobiological interest, perhaps associated with late-stage activity in the evolution of Valles Marineris, and suggest that the floor of Coprates Chasma is promising target for the in situ exploration of Mars.
Permanent Link: http://hdl.handle.net/11104/0272227