Coils and Polygonal Crust in the Athabasca Valles Region, Mars, as Evidence for a Volcanic History

Abstract

A Volcanic Valley on Mars The formation of the Athabasca Valles, a valley network near the equator of Mars, has been debated for over a decade; both lava and water ice have been implicated. Some studies have attributed the polygonally patterned ground in this region to frost wedging in an ice-rich soil. Using images of the Athabasca region from the High Resolution Imaging Science Experiment onboard Mars Reconnaissance Orbiter, Ryan and Christensen (p. 449) detected numerous spirals on polygonally patterned ground. The spiral shapes are consistent with those of lava coils that form on the surface of Hawaiian lava flows, and cannot be explained by ice-related activities.