Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

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…

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…

Single Station Methane Gas Detector Single Station Methane Gas Detector: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a single station methane gas detector is a device consisting of electrical components that are capable of measuring methane soil gas concentrations indoors, and initiating an alarm. The single…

Fault Scarp Fault Scarp: In the field of geology, a dip-slip fault scarp is a steep slope that is formed directly by fault movement. It occurs along the line of a normal fault, reverse fault, or transform fault. A fault scarp represents the planer surface of the fault before erosion and weathering modify it.

Reverse Fault Reverse Fault: In the field of geology, a reverse fault is a dip-slip fault in which the hanging wall moves upwards, relative to the footwall. The average dipping angle of a reverse fault ranges from 45 to 90 degrees. However, if less than 45 degrees, it becomes a “thrust fault.” Reverse faults are…