An Index fossil, in the field of paleontology, refers to a fossil that identifies and dates the stratigraphic unit that it is observed to exist in. Index fossils can combine a wide geographic range. And they can really narrow down the classifications of most stratigraphic units.
Volcanic Rock (Igneous) Definition A “Volcanic Rock” is an igneous rock that is finely crystalline and glassy (or aphanitic). To illustrate, volcanic rocks result from volcanic action at the earth’s surface. Typically, this also includes igneous intrusions that are “near-surface,” which may otherwise be considered plutonic. This action results in a final rock that is…
Normal Fault Normal Fault: In the field of geology, a normal fault is a type of dip-slip fault where the hanging wall moves downwards from the footwall. The average dipping angle of a normal fault ranges from 45 to 90 degrees. Normal faults are the opposite of reverse faults. Detachment Fault Detachment Fault: A detachment…
Retaining Wall Retaining Wall: A structure that provides the support needed to hold (in place) a mass of earth, preventing it from moving downhill. Retaining walls are relatively rigid structures comprising footings and a drainage system, in order to retain the soils between two different elevations. Updated May 25, 2020. Construction & Design A lot…
Hydrogen Sulfide Soil Gas (In Natural Gas) Hydrogen Sulfide: Hydrogen sulfide (H2S) soil gas geologically occurs upon the thermal and microbial decomposition of subsurface organic material deposits. It is typically identifiable in biogenic and petrogenic natural gas sources, along with higher concentrations of methane soil gas. Additionally, nitrogen, oxygen, hydrogen, ethane, and isobutane exist within natural…
Environmental Law Environmental Law refers to the various categories of law that are put in place to protect the quality and condition of the earth and the environment. This sect of law aims to protect the well being of people and to preserve the earth’s natural resources, reserves, and wildlife. In fact, environmental laws apply…
Growth Fault Growth Fault: In geology, a growth fault is a strike-slip fault or dip-slip fault that moves contemporaneously with deposition. This causes the throw (amount of vertical displacement) to increase with depth and the strata to be thicker on the downthrown side as compared to the upthrown side.
