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…

Seiche Definition The term “Seiche” in geology refers to a wave-oscillation, that comes from any surface body of water, that is initiated by an earthquake or changes in atmospheric pressure. For instance, the rippling waters of a lake or at the bay of an ocean.

Ultramafic Definition In the study of geology, the term “ultramafic” refers to an igneous rock that comprises up to 90% mafic minerals, or more.

Liquid Limit (LL) “Liquid Limit (LL)” in the field of geological engineering, refers to the upper limit of the “plastic state.” This is a separation of the plastic phase and viscous liquid phase when measuring soil consistency. Mathematically, it is the water content (basing on the percent of dry weight), at which two sections of…

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

Oblique-Slip Fault Oblique-Slip Fault: In geology, an oblique-slip fault is a fault that moves parallel to the strike or dip of the fault plane.