Evidence of a Martian spatter cone south of Pavonis Mons

Abstract

Spatter cones are a common mafic explosive volcanic feature observed on Earth associated with Hawaiian and Strombolian-style lava fountaining. Across Mars there are numerous explosive volcanic features assessed to be accumulations of cold pyroclasts (e.g., scoria cones, tuff rings) but identification of welded and fused explosive deposits (i.e., spatter) has only recently been investigated. We present evidence indicating the presence of a Martian spatter cone south of Pavonis Mons and a comparison to a spatter cone formed during the 2021 Fagradalsfjall eruption, Iceland. The morphology and morphometry of the possible Martian spatter cone are more consistent with agglutinated rock like the spatter cone formed during the Fagradalsfjall eruption than poorly consolidated tephra, characteristic of scoria cones. In addition, the size of the two spatter cones falls within anticipated dimensions based on a simple ballistic trajectory model. Evidence for spatter included high angled slopes, knobby yet layered surface textures, rounded boulder talus, and thermophysical properties consistent with material that is more indicative of rock than scoria. The evidence indicates that the volcanic feature South of Pavonis Mons should be classified as a spatter cone. Identification of a Martian spatter cone has implications for eruption dynamics, magmatic volatile content, and environmental conditions.