Threshold Geological Criteria
- Presence of subaqueous sediments or hydrothermal sediments (equal 1st priority),
hydrothermally altered rocks or low-T fluid-altered rocks (equal 2nd priority)
- Presence of minerals indicative of aqueous phases (e.g., phyllosilicates, carbonates, sulfates, etc.) in outcrop
- Noachian/Early Hesperian age based on stratigraphic relations and/or crater counts
- Access to unaltered igneous rocks as float
- Not a Special Region
Potential Qualifying Geological Criteria:
- Morphological evidence for standing bodies of water and/or fluvial activity (deltaic deposits, shorelines, etc.).
- Assemblages of secondary minerals of any age.
- Presence of former water ice, glacial activity or its deposits.
- Igneous rocks of Noachian age, of known stratigraphic relation, better if including exhumed megabreccia.
- Volcanic unit of Hesperian or Amazonian age well-defined by crater counts and well-identified by morphology and/or mineralogy.
- Probability of samples of opportunity (ejecta breccia, mantle xenoliths, etc.).
- Potential for resources for future human mission.