Basaltic Ring Structures as an Analog for Ring Features in Athabasca Valles, Mars

Abstract

Basaltic ring structures (BRSs) are enigmatic, quasi-circular landforms in eastern Washington State that were first recognized in 1965. They remained a subject of geologic scrutiny through the 1970 s and subsequently faded from the spotlight, but recent Mars Orbiter Camera (MOC) images showing morphologically similar structures in Athabasca Valles, Mars, have sparked renewed interest in BRSs. The only known BRSs occur in the Channeled Scabland, a region where catastrophic Pleistocene floods from glacial Lake Missoula eroded into the Miocene flood basalts of the Columbia Plateau. The geologic setting of the martian ring structures (MRSs) is similar; Athabasca Valles is a young channel system that formed when catastrophic aqueous floods carved into a volcanic substrate. This study investigates the formation of terrestrial BRSs and examines the extent to which they are appropriate analogs for the MRSs in Athabasca Valles.