“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.

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…

Growth Fault Growth Fault: In geology, a growth fault is a strike-slip fault or dip-slip fault that moves contemporaneously with deposition. This causes the throw (amount of vertical displacement) to increase with depth and the strata to be thicker on the downthrown side as compared to the upthrown side.

Degree of Saturation (SR) “Degree of Saturation” (SR) is an engineering geology term and refers to the ratio of the volume of water to the total volume of void space. The Degree of Saturation or SR-value ranges from 0% to 100% (0% being completely dry, and 100% being fully saturated). Degree of Saturation Formula Degree…

Gap-Graded The term “Gap-Graded” is used by geologists, engineers, and soil scientists in the geotechnical engineering field to describe the gradation of a soil sample, specifically when some particle sizes are missing. Aside from being “gap graded,” a soil sample can be described as “well-graded” (also referred to as poorly sorted), or “poorly graded” (or…