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.

Anion Anion: In the fields of chemistry and geochemistry, an anion is a negatively charged ion. The oppositely charged ion is a cation.    

Confined Aquifer Confined Aquifer: In the hydrogeology branch of geology, a confined aquifer is an aquifer that is overlain (and underlain) by a layer of low permeability, such as clay, shale, or silty clay. In fact, the two confining layers contain the storage and flow of groundwater, such that the aquifer maintains hydraulic pressure (or…

Plutonic Rock (Igneous) Definition The term “Plutonic” in the field of geology refers to an igneous rock, wherein the magma had originally cooled, solidified, and crystalized underground. A plutonic rock is generally coarsely crystalline (phaneritic) and is formed during a massive geologic intrusion of magma. In fact, outcropping (or daylighting) plutonic rocks are geologic features…

Ultramafic Definition In the study of geology, the term “ultramafic” refers to an igneous rock that comprises up to 90% mafic minerals, or more.