Settlement Definition
In the field of geology, The term settlement means a gradual downward movement of the ground surface. This is generally due to soil compression at on a larger scale, atdepths that are below the ground surface.
In the field of geology, The term settlement means a gradual downward movement of the ground surface. This is generally due to soil compression at on a larger scale, atdepths that are below the ground surface.

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.

“Toe” of a Slope Definition The “toe” of a slope is essentially the bottom, or baseline section, of the soil mass comprising the slope. It is also defined as the outermost margin of displaced material during a landslide. The toe of a slope is farthest away from the head scarp.

Retaining Wall Retaining Wall: A structure that provides the support needed to hold (in place) a mass of earth, preventing it from moving downhill. Retaining walls are relatively rigid structures comprising footings and a drainage system, in order to retain the soils between two different elevations. Updated May 25, 2020. Construction & Design A lot…

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

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…

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…