Transgression Transgression: In geology, the term transgression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water advancing onto land. To illustrate, when transgression occurs over millions of years, geologists find a layer of sand, overlain by shale, and overlain again by limestone. The opposite of…

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

Mesosphere Mesosphere: The mesosphere of a terrestrial planet is the third member of the atmosphere. On Earth, the mesosphere starts atop the stratosphere at approximately 50 kilometers above mean sea level and terminates roughly 85 kilometers above mean sea level. The mesosphere is where most meteors burn to determination. Like the stratosphere, the air in…

Permeability “Permeability” in engineering geology and geotechnical engineering refers to the property of a soil sample (or porous rock) which relates to transmitting a fluid within. Permeability measures the relative case of flow under unequal pressure. Permeability is calculated using Darcy’s Law.

“Test” Definition in Paleontology In the field of paleontology, a subsidiary of geology, the term “test” refers to the external hard part of an invertebrate.

Mafic Definition In geology, “mafic” is a term that describes an igneous rock that has an abundance of darker color minerals.