Transgression Transgression: In geology, the term transgression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water advancing onto land. To illustrate, when transgression occurs over millions of years, geologists find a layer of sand, overlain by shale, and overlain again by limestone. The opposite of…

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

Time Stratigraphic Unit Definition A Time Stratigraphic Unit, or a Chronostratigraphic Unit, is a rock unit that is characterized by geological formations, during a specific period of time. This serves as a reference for all rocks formed during the same time period.

Perforated Horizontal Pipe in Methane Mitigation Perforated Horizontal Pipe: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a perforated horizontal pipe is a PVC or ABS pipe that contains a series of small holes or narrow openings placed equidistantly along the length of the pipe, and is…

“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.

Topple Definition Topple – Slope movement due to forces that cause an overturning moment about a pivot point below the center of gravity of the unit.