LIPs on Venus

Venus, a planet similar to Earth in heat budget lacks plate tectonics, yet displays ample evidence of extensive volcanic and tectonomagmatic processes, including regions large enough to be considered LIPs. Thus Venus provides an excellent opportunity to examine large-scale magmatic processes outside a plate tectonic framework. I discuss four groups of Venus’ largest tectonomagmatic provinces: volcanic rises, large coronae (Artemis, Heng-O, Quetzalpetlatl, Atahensik), crustal plateaus, and ‘plains with wrinkle ridges’, unit pwr. Unit pwr, widely interpreted as representing catastrophic resurfacing, has been suggested to be the solar system's largest LIP. I argue herein that these features, each covering ∼1 million km or more, and recording extensive volcanic activity, record different evolutionary processes, including both endogenic and exogenic processes. Volcanic rises represent surface manifestations of deep-mantle plumes on thick lithosphere. Large coronae may record different evolutionary paths. Artemis represents a plume signature on thin lithosphere. More mapping is required to determine if Heng-O formed by endogenic or exogenic processes. Preliminary mapping suggests Quetzalpetlatl represents a young mantle plume; Atahensik marks a diapiric structure, though buoyancy mode is unconstrained. Crustal plateaus record solidification of huge lava ponds formed by massive partial mantle melting caused by large bolide impact on thin lithosphere. The status of unit pwr as the largest LIP within the solar system is challenged based on geological considerations, and results of a growing body of geologic mapping. © 2007 Elsevier B.V. All rights reserved.