Graben–fissure systems can have radiating, linear or arcuate/circumferential geometry and are generally interpreted as the surface expressions of underlying dyke swarms on Venus. Coronae on Venus are large, circular surface features and form in response to magmatic loading of the crust over zones of partial melting at the tops of mantle plumes that impinge on the base of the thermal lithosphere. This project has mapped 32 different graben-fissure systems in the study area (10°-20° N, 30° -50° E) within the Mead Quadrangle: 24 of these systems are spatially associated with 4 different coronae
(Didilia, Pavlova, Isong, and Ninmah), and in 8 cases are genetically linked. Eight remaining systems are not related to coronae. Five have foci associated with known magmatic centers (corona or volcano). Two others radiate from a cryptic magmatic center. Additional arcuate systems are interpreted to be circumferential about magmatic centers.