An overview of explosive volcanism on Mars

Decades of space exploration reveal that Mars has been reshaped by volcanism throughout its history. The range observed volcanic landforms shows effusive and explosive eruptions have occurred, albeit unevenly in time space. Evidence for volcanism—characterized as which magma is disrupted the expansion dissolved gases or an interaction with external volatiles—is less common than evidence activity. Nonetheless, indications identified. Examples include, old, rimless depressions, termed paterae, often on summits broad topographic rises very gentle flanks, are located mainly around Hellas impact basin. Also, fields kilometre-sized cones interpreted scoria cones, tuff rings extensive clusters sub-kilometre pitted northern lowlands proposed to be rootless i.e. constructional features caused accumulation fragments. Finally, layered deposits widely spread equatorial areas (e.g., Medusae Fossae Formation), stacks ash a putative bomb rover, also point protracted history Mars. Yet some these interpretations remain matter scientific debate. discovery triggered interest theoretical aspects such under gravitational atmospheric conditions different from those Earth. These studies indicate would behave differently This because lower pressure gravity can affect all stages eruption including ascent magma, process degassing fragmentation, transport deposition pyroclasts, and, cases, formation volcanoes themselves. On Earth, responsible most land, so relatively sparse occurrence surprising, especially considering martian environmental well wide volatiles Earth ought favour fragmentation hence pyroclasts associated edifices, even if volumes were present usual relative dearth activity therefore represents gap our understanding volcanism, suggesting there may considerable compositional differences between manifests Understanding important, provides insight into planet’s composition plays crucial role evolution atmosphere release magmatic gases, ability geological biological processes operating surface planet. In this paper, we overview Mars—from both observational perspectives—and discuss implications Red Planet.