**Appendices and nomenclature**


*Special Crater Types on Vesta and Ceres as Revealed by Dawn DOI: http://dx.doi.org/10.5772/intechopen.96671*


*Solar System Planets and Exoplanets*

material below the craters [43].

comprises up-doming of material beneath the craters.

subsurface [44].

**5. Conclusions**

these crater types.

**Appendices and nomenclature**

FFC Floor-fractured crater

RMC Ring-mold crater Ahuna Mons 10.48° S, 316.2° E

HED Howardite-Eucrite-Diogenite metroids

in some regions of Occator the space between fractures contains blocky fragments that seem to limit the tear faults. Other fractures are cut by slides [44]. Dantu also shows pitted fractures indicating the influence of volatile components in the

The formation of floor fractured craters (FFCs) is mainly suggested by cryomagmatic intrusion [43, 44], at which the cryomagmatic intrusion must have been trapped vertically and horizontally by weak material below the crater. Underlying reservoirs can feed such an intrusion and forming domes which uplifting and fracturing the overlying, brittle crater floor [43, 44]. Additionally, length, width and strike of the fractures vary for each crater and suggest independent formation mechanisms and imply different surface and subsurface materials. [44] also propose the following formation processes for FFCs: (1) tear-off edges in case of slumping of the crater wall, (2) cooling melting processes that lead to sinkage of the crater floor, (3) degassing, and/or (4) tectonic interactions. All four mechanism also

Even on small bodies impact craters reveal a multifaced morphology as caused by different formation processes. Impacts into a slope can cause the formation of asymmetric craters. Whereas steep slope angles and bigger slope sizes promote the formation of the asymmetries. However, the formation of ring-mold crater and floor-fractured crater is mainly cause by the subsurface conditions. An impact into a thin layer of regolith on top of a subsurface ice-layer lead to the formation of ring-mold crater. The occurrence of ring-mold craters can be used to detect regolith covered ice layers. Furthermore, the maximum depth of associated bowl-shaped craters can be used to estimate the depth of the ice and the thickness of overlying regolith. Floor-fractured craters is mainly proposed by cryomagmatic intrusion, which are fed by underlaying reservoirs. But also tear-off edges in case of slumping of the crater wall, cooling melting processes that lead to sinkage of the crater floor, degassing, and/or tectonic interactions are supposed to promote the formation of

Other FFCs on Ceres shows a roughly north–south trending set of curvilinear fractures and a smaller set of conjugate fractures associated with the north south fractures near the central peak in the case of Azacca (**Figure 4D**, **D1**), or contains fractures at the base of the northwestern crater wall as well as fractures orthogonal and parallel to the central crater structure in the case of Ikapati [43, 44]. Class 4 FFCs, however, are characterized by having v-shaped moats and usually hummocky floors which are more shallow than other cerean craters of their diameter. The fractures of the crater floors are less distinct. Furthermore, the craters are smaller than Class 1 FFCs [43]. Large FFCs on Ceres with diameters >50 km shows the most similarities with Class 1 lunar FFCs, while smaller FFCs are more consistent with Class 4 lunar FFCs. These results imply a similar formation of fractures due to the intrusion of a low-density

**218**
