Soil Creep Definition Soil Creep is a type of landslide that entails the slow and gradual movement of a soil mass (or even some loose rock) materials.

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.

Oblique-Slip Fault Oblique-Slip Fault: In geology, an oblique-slip fault is a fault that moves parallel to the strike or dip of the fault plane.

Effective Stress (σ’) “Effective Stress” (σ’) is a geotechnical engineering term. Effective Stress is a function of “total stress,” and is due to the solid particles of soil. Effective stress represents an excess of stress above pore-water pressure (or neutral stress). Effective Stress Formula Effective Stress = Total Stress – Pore-Water Pressure.

Topple Definition Topple – Slope movement due to forces that cause an overturning moment about a pivot point below the center of gravity of the unit.

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