Cation Cation: In the fields of chemistry and geochemistry, a cation is a positively charged ion. The oppositely charged ion is an anion.

Runoff (R) The term “Runoff” (R) in hydrogeology and geology refers to the part of rainfall which accumulates on the ground surface and naturally forms into flowing streams.

Diagenesis Diagenesis: In geology, diagenesis refers to the physical and chemical changes of a sedimentary formation when compaction and lithification occur over time.

“Test” Definition in Paleontology In the field of paleontology, a subsidiary of geology, the term “test” refers to the external hard part of an invertebrate.

Rock Stratigraphic Unit In the field of geology, a rock stratigraphic unit, or a lithostratigraphic unit, is a geologic formation that is identifiable by a specific lithology, as well as a consistent stratigraphic position. For example, the Monterey Formation is a rock stratigraphic unit, as it tends to consistently comprise the same gravel and sand…