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…

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

Wing Dam or Wing Dike A “Wing Dam” or “Wing Dike” refers to a dam that intentionally retains a fraction of the width of a flowing water source. Unlike a conventional dam, a wind dam aims to divert the path of water flow. Additionally, a wing dike can control the velocity of water flow. For…

Feldspars Feldspars: In the field of geology, and the branch of mineralogy, feldspars are a mineral group, that is the most common amongst the earth’s crust. In fact, there are two types of feldspars: plagioclase feldspar and orthoclase feldspar.

What is an Embankment Dam? An Embankment Dam is a freshwater-retaining structure comprising excavated rock, soil, or a combination of rock and soil from nearby geological formations.  In fact, Embankment Dams are known as an “Earthfill Dam” when filled with soil, and a “Rockfill Dam” when filled with rocks. Earthfill Dams are most common. The…

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…