An explosive mud volcano origin for the pitted cones in southern Utopia Planitia, Mars

Pitted cones are cone-shaped structures, spanning from meters to kilometers in size, characterized by summit depressions. They are widely distributed on the surface of Mars with various origins, such as rootless cones, mud volcanoes, cinder or scoria cones, tuff rings or cones, pingos, and dirt cones. If the pitted cones identified in southern Utopia Planitia are mud volcanoes, as is speculated, they could be of particular interest due to the fact that mud volcanoes on Earth bring sediments from a depth of meters to kilometers to the surface. In this study, we have investigated the pitted cones near Zhurong rover’s landing site in southern Utopia Planitia, utilizing recent images and digital elevation models obtained from the High Resolution Imaging Camera instrument onboard China’s Tianwen-1 orbiter. By leveraging the high-resolution images and digital elevation models, we have conducted a geometric measurement to distinguish the origin of pitted cones in the vicinity of the Zhurong rover. The morphological characteristics of these pitted cones indicate an explosive mud volcano origin. These explosive mud volcanoes could have formed by the violent eruption of subsurface overpressurized sediments generated from the combined effect of overburden pressure and anomalous high heat flow. The sediments forming the pitted cones in the northern plains could be the remnants of an ancient ocean. With future in-situ observations of these pitted cones, we hope to gain further insights into the sediments of the putative northern ocean, as well as the physical and chemical properties of the Martian subsurface during the formation of the pitted cones.