Body-Wave Magnitude Body-Wave Magnitude: A method for determining earthquake size from the amplitude of body waves. The body-wave magnitude focuses on P-waves and S-waves, which travel faster through the Earth’s crust and mantle.

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…

Strike-Slip Fault or Transform Fault Strike-Slip Fault (Transform Fault): In the field of geology, a strike-slip fault, or a transform fault, is a fault in which movement is parallel to the strike of the fault plane. The opposite of a strike-slip fault is a dip-slip fault. Left-Lateral or Right-Lateral Strike-Slip Fault A transform fault can…

Mafic Definition In geology, “mafic” is a term that describes an igneous rock that has an abundance of darker color minerals.

Petroleum Extraction Well (Oil Well) Petroleum Extraction Well (Oil Well): A petroleum extraction well, or an oil well, is a deep borehole or shaft sunk into the Earth for the exploration of oil or gas. Additionally, injection wells are often drilled to inject fluids or gas for stimulating oil recovery, re-pressurizing or pressure maintenance of…

Dilatancy “Dilatancy” is the increase in the bulk volume of a soil substance during deformation. Dilatancy is caused by the change from a close-pack structure to an open-pack structure.