“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.
In the field of paleontology, a subsidiary of geology, the term “test” refers to the external hard part of an invertebrate.

Hydrogen Sulfide Soil Gas (In Natural Gas) Hydrogen Sulfide: Hydrogen sulfide (H2S) soil gas geologically occurs upon the thermal and microbial decomposition of subsurface organic material deposits. It is typically identifiable in biogenic and petrogenic natural gas sources, along with higher concentrations of methane soil gas. Additionally, nitrogen, oxygen, hydrogen, ethane, and isobutane exist within…

Asthenosphere Asthenosphere: The asthenosphere underlies the lithosphere. The Asthenosphere comprises the upper mantle, where isostatic adjustments are made, and where magma is generated. It is also in this part of the earth, where seismic waves strongly attenuate.

Vapor Intrusion Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.

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

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…

Transmissivity Transmissivity: In geology and hydrogeology, transmissivity (T) represents the capacity of an aquifer to transmit water of the prevailing kinematic viscosity. Formula T=Kb, where b = saturated thickness of the aquifer. Dimensions are gallons per day per foot (gpd/ft) or feet squared per day (ft^2/day).