In the field of geology, a rock stratigraphic unit, or a lithostratigraphic unit, is a geologic formation that is identifiable by a specific lithology, as well as a consistent stratigraphic position. For example, the Monterey Formation is a rock stratigraphic unit, as it tends to consistently comprise the same gravel and sand types, and consistently makes contact with other geologic formations, as it spans across the entire western portion of California.
Seismic Risk Definition Seismic risk is the probability that a subject site will be adversely affected by any seismic hazard, such as an earthquake. Seismic risk tends to increase in areas that are more earthquake-prone and vulnerable to damage. And vulnerability refers to the potential impact on people, as well as properties. For instance, places…
Design Methane Concentration Design Methane Concentration: In accordance with the Los Angeles Department of Building and Safety Methane Code, Ordinance Number 175790, a Design Methane Concentration is the highest recorded concentration of methane soil gas detected during the course of methane testing on a property. The Design Methane Concentration is what defines the level of…
Hydraulic Conductivity (K) “Hydraulic Conductivity” (K), in hydrogeology and hydrology, represents the capacity of a porous medium (such as soil) to transmit water, as per Darcy’s Law. To illustrate, the rate at which fluid can move through a permeable medium (such as soil), depends on the properties of that soil (such as intrinsic permeability) and…
Petrogenic Gas Petrogenic Gas: In geology, petrogenic gas refers to natural gas that is the byproduct of the thermal decomposition of biological and organic matter. In fact, this is the same process that results in the geological formation of petroleum underground. For instance, methane soil gas hazards in Los Angeles Methane Zones are typically resulting…
Ultramafic Definition In the study of geology, the term “ultramafic” refers to an igneous rock that comprises up to 90% mafic minerals, or more.
Geology Geology: Geology is a field of science relating to the earth, including but not limited to the earth’s resources, physical processes, chemical properties, history, and future. Additionally, the science of geology includes the study of other terrestrial planets, such as Mercury, Venus, or Mars. Branches of Geology There are numerous branches of geology that…
