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…

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

Maximum Soil Screening Levels (MSLs) Maximum Soil Screening Levels (MSLs): MSLs are a list of risk-based hydrocarbon concentrations for soil pollution evaluations, that is developed by the California Regional Water Quality Control Board. These screening levels are based on the Leaking Underground Fuel Tanks (LUFT) Manual, for cleaning up soil contamination from leaking USTs. However, MSLs…

Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

“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.

Aphanitic Definition Aphanitic: In geology, the term aphanitic describes the texture of plutonic or volcanic igneous rocks, with grains that are not visible to the naked eye. In fact, an aphanitic texture is usually the result of faster cooling and solidification of liquid magma.