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…

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.

Soil Creep Definition Soil Creep is a type of landslide that entails the slow and gradual movement of a soil mass (or even some loose rock) materials.

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

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.