Type Section Geologic Definition In geology, the term “type section” refers to a specific stratigraphic unit, that can be compared to other parts of the geologic unit. For a type section, it’s preferred to describe the location where the geologic unit has the maximum thickness, and where the top and bottom units are observable.

Dry Strength “Dry Strength” is a value that represents the strength of a soil sample, when dry, as determined by the crushing test. There is a common geotechnical engineering laboratory procedure for determining the cohesiveness or plasticity of a sample with organic or inorganic clays and silts.  

Mineraloid Definition The term “mineraloid” refers to a natural earth substance that appears to be similar to a genuine mineral, although lacks any form of internal structure and crystal form. Nonetheless, a mineraloid does comprise true minerals within it. For instance, Fire Opal and Blue Opal are not minerals because they are amorphous (do not…

Unconfined Aquifer Unconfined Aquifer: In the hydrogeology branch of geology, an unconfined aquifer is an aquifer that has a water table. In fact, an unconfined aquifer can only be the uppermost hydrogeologic unit and is particularly one that has no hydraulic head (or pressure) that is equal to atmospheric pressure. To illustrate, depth to groundwater…

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

Mechanical Extraction System Mechanical Extraction System: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a Mechanical Extraction System is one of the Active Methane Mitigation criteria for methane mitigation systems in buffer zones and methane zones.  A mechanical extraction system uses machines that remove methane gas from below…