Study of the solid Earth and its history. Geological evidence provides the stratigraphic and environmental context for fossils.
Study of mineral compositions, structures and properties.
A naturally occurring solid substance with a characteristic composition range and internal structure. Synthetic analogues can be engineered as hosts for selected waste constituents.
A mineral whose structure contains silicon–oxygen units. Different linkages give isolated groups, chains, sheets or extended frameworks. Refractory silicate grains are an important solid component of a protoplanetary disk.
A uranium titanate with ideal composition . It occurs in natural actinide-bearing minerals and can appear in titanate ceramic waste forms.
A calcium zirconium titanate with ideal formula . Its structural variants and substitution mechanisms are important in actinide-bearing ceramic waste forms.
A monoclinic zirconolite polytype with a four-layer repeat, observed in some actinide-substituted composition ranges.
A monoclinic zirconolite polytype with a two-layer repeat. Its zirconium site has sevenfold oxygen coordination.
Material deposited by physical, biological or chemical processes that may later be altered into sedimentary rock.
Change in relative continental positions through geological time, as explained within plate tectonics. Ancient connections must be reconstructed rather than read from modern maps.
A former southern supercontinent. Its changing connections constrain historical biogeography, without implying that every shared lineage originated by vicariance.
A chronostratigraphic framework organizing Earth history into named intervals. Numerical boundary ages and the uncertainty of a particular fossil date are separate matters.
