Regression: In geology, regression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water withdrawing from the land. To illustrate, when regression occurs over millions of years, geologists find a layer of limestone, overlain by shale, and overlain again by limestone. The opposite of regression is transgression.
Natural Gas Natural Gas: In geology, natural gas means combustible hydrocarbon gas that forms by natural geological or biological processes. To illustrate, natural gas that forms by geological processes is the thermal decomposition of buried organic materials. Whereas natural gas that forms via biological processes entail the microbial decomposition of buried organic material. Natural gas…
Tsunami Tsunami: In the seismology branch of geology, a tsunami is an oceanic wave (gravitational) that is produced by seismic activity on the ocean floor. Common triggers of tsunamis are large-scale short duration earthquakes, volcanic eruptions, or other submarine earth movements such as subsidence and slope failure.
Surface-Wave Magnitude “Surface-Wave Magnitude” is the magnitude of an earthquake that scientists estimate using measurements of the amplitude of surface waves.
Methane Soil Gas Methane Soil Gas: In geology, methane soil gas refers to the confinement of CH4 within the interstitial pore spaces of subsurface soils. On Earth and potentially on Mars, methane derives from subsurface pockets of biogenic and petrogenic natural gas. To illustrate, accumulations of buried organic matter decay via microbial or thermal degradation….
Thrust Fault Thrust Fault: In the field of geology, a thrust fault is a reverse fault in which the fault plane dipping angle is less than 45 degrees. Thrust faults are dip-slip faults, and can also be listric faults. For instance, the fault underlying the western embankment of the historical St. Francis Dam in Saugus,…
Sedimentary Rock Definition In geology, the term “Sedimentary Rock” refers to the classification of rock that is the result of the gradual consolidation and deposition of loose particles of other rock classifications (igneous or metamorphic). Alternatively, sedimentary rocks can also form by the accumulation and precipitation of other natural chemical solutions in a depositional environment….
