Layer
- Name
- Sublimation residue made of Magnetite 63wt%, NH4-nontronite 22wt%, Antigonite 9wt%, Dolomite 6wt%
- Type of layer
- granular
- Texture
- other
- Type of porosity
- particulate
- Comments
- The layer is a porous structure, made of pale spheres of nontronite "ribbons", embedded in a grey matrix of aggregated mineral grains. The spheres appear to be made of "ribbons" of nontronite (only few micrometers thick) interlaced or connected together. After sublimation of the water, the places previously occupied by the water crystals are now empty, resulting in an high porosity of the sublimation residue, also called sublimation mantle. The observed ribbons are probably the relics of the water crystals interfaces.
- Formation mode
- fractionated sublimation
- Comments
- The layer was produced by sublimation of ice mixed with minerals.