Extrusive Rocks: In the volcanology branch of geology extrusive rocks are igneous rocks that have been erupted onto the Earth’s surface, before forming and crystallizing. On the other hand, intrusive rocks form and crystallize under the Earth’s ground surface. Extrusive rocks are typically microcrystalline and aphanitic, because of the faster rate of cooling and solidification.
Milliequivalent per liter Milliequivalent per liter (meq/L): A unit used to express the chemical equivalence of the concentration of solutes in a solution. It is calculated by dividing the concentration of a substance (in mg/L) by its equivalent weight. This measurement helps in understanding the reactive capacity of ions in the solution.
What is a Concrete Gravity Dam? A Concrete Gravity Dam is also known as “Gravity Arch Dam,” and is a freshwater-retaining concrete structure that has a wider footing (base) than the top-section. The purpose of a Concrete Gravity Dam is to maintain a low center of gravity, in order to avoid collapsing in the event…
Metamorphic Rock Definition In the field of geology, the term “Metamorphic Rock” refers to a rock classification that is the result of the alteration of prior existing sedimentary rocks or igneous rocks. The alteration process is “metamorphosis, and can take place by various methods and environments. The metamorphosis process produces specific metamorphic rocks, on the…
Alquist-Priolo Earthquake Fault Zoning Act Alquist-Priolo Earthquake Fault Zoning Act: The Alquist-Priolo Earthquake Fault Zoning Act is a law that assists geologists to define “active faults” versus “potentially active faults.” The process entails using the same aging criteria as the United States Geological Survey (USGS) and the California Geological Survey (CGS). In fact, California policy requires…
Regional Metamorphism Regional Metamorphism: Metamorphism acts over large areas resulting from applied pressures of 3,000 to 10,000 bars and temperatures of 400°C to 800°C. Regional metamorphism is also referred to as dynamothermal metamorphism.
Critical Void Ratio The “Critical Void Ratio,” in soil science and geology, represents the final void ratio of a soil sample, at ultimate strength. And Critical Void Ratio is achieved by the loose and dense samples of the same soil post-shearing.
