Spinifex Textures in Martian Lavas: Crystallization Experiments on Yamato 980459

Robotic geologists (rovers, landers, and orbiters)have returned a substantial volume of data that specifically relate to the petrology of martian igneous rocks, which are invaluable in understanding magmatic processes on Mars. One of the best ways to understand this returned data is with experimental petrology. Building a repository of experimental samples with martian compositions can provide us with a library of analog samples with which we can compare to findings from the martian surface. By constraining the range of texture sin martian compositions that correspond to specific temperatures, viscosities, cooling rates, etc., experimental databases would allow for quick interpretations of such textures observed by rovers and landers in martian rocks. Spinifex textures-large skeletal olivine or pyroxene dendrites surrounded by smaller dendrites or glass-form in a highly constrained parameter space within ultra-mafic to mafic, Mg-rich, high-temperature, low-viscosity rocks that have undergone ahigh degree of undercooling–crystallized at temperatures far below their liquidus. Spinifex is commonly found in specific stratigraphic locations in thick ultramafic-mafic lava flows and transient lava lakes. If spinifex is seen on Mars, it might help to constrain what part of a lava flow’s stratigraphy is being observed in combination with revealing the lava flow’s temperature, viscosity, composition, and more. Finding spinifex on Mars would also support those lavas being derived from a primitive melt, allowing them to be used to calculate mantle potential temperature at their time of eruption. This would be a useful value for comparing mantle thermal properties in different locations and ages on Mars and for comparing against Earth. Having an experimental repository of spinifex textures made from martian compositions will allow for an easier identification of these primitive lavas by rover.