Tectonic analysis of fracturing associated with occator crater

Abstract

Occator crater, a Ceres crater that hosts multiple bright spots on its floor, has several sets of fractures associated with it. A tectonic analysis of each of these fracture sets suggests that the concentric and radial fractures around the central pit and the concentric fractures high on the crater wall (near the rim) most likely formed due to well known impact cratering processes. Uplift of the crater floor due to magmatic injection is suggested to have resulted in the concentric floor fractures at the base of the crater wall, as well as the cross-cutting fractures in the lower part of the southwestern wall. A mathematical analysis shows that a cryomagmatic plume (diapir) could have both reached the height necessary to cause fracturing within Occator, and that the stresses required are reasonable. Expansion a lobate flow from beneath is proposed to have formed those linear fractures associated with the Vinalia Faculae. Circumferential fractures surrounding Occator appear to have formed due to the volumetric compaction of the ejecta blanket over the buried pre-existing topography.