Index Fossil Definition 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.

Methane Mitigation Soil Gas Pressure Sensor Methane Mitigation Soil Gas Pressure Sensor: A Methane Mitigation Soil Gas Pressure Sensor is a device that measures and communicates sub-slab soil gas pressure to a methane control panel system. High levels of methane soil gas then trigger the integrated methane alarm system to notify occupants of danger. Much…

Regression 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…

Type Section Geologic Definition In geology, the term “type section” refers to a specific stratigraphic unit, that can be compared to other parts of the geologic unit. For a type section, it’s preferred to describe the location where the geologic unit has the maximum thickness, and where the top and bottom units are observable.

Perched Groundwater Perched Groundwater – In geology, “perched groundwater” refers to unconfined groundwater which separates from an underlying body of groundwater by an unsaturated zone or vadose zone.

Zoning Mineralogy Definition Zoning is a variation of crystal composition that is a characteristic of feldspars. To illustrate, the center of a feldspar mineral is formed by a high-temperature phase, whereas the exterior is formed by a low-temperature phase.