▪ Abstract Earth, Venus, and Mars all exhibit populations of giant (radiating, linear, and
arcuate) mafic dike swarms hundreds to> 2000 km in length. On Earth the dikes are exposed
by erosion, while on Venus and Mars their presence is mainly inferred from associated
volcanic morphology and surface deformation. The apparent absence of plate tectonics in
the geologic record of Venus and Mars means that the observed population of swarms
remains geometrically intact, while on Earth plate tectonics has fragmented swarms. About …