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…

Porosity (n) “Porosity” (n), in the geological engineering field, is a percentage value that represents the bulk volume of a rock or soil, that is occupied by the void space within. Porosity (n) Formula Porosity (n) = [(Volume of Voids ÷ Total Volume) x 100%]

Well Log (Boring Log) Well Log: A geological well log (or boring log) is a detailed record of subsurface materials encountered during a drilling project. Boring logs, or well logs, are written by a geologist, and describe the physical subsurface characteristics and lithological units encountered during well-plotting. Well logs include information about depth, different formations,…

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

Hooke’s Law “Hooke’s Law” is a geological statement relating to the elastic deformation of rocks.  Hooke’s Law states the strain of an earth-material is linearly proportional to the applied stress.

Time Stratigraphic Unit Definition A Time Stratigraphic Unit, or a Chronostratigraphic Unit, is a rock unit that is characterized by geological formations, during a specific period of time. This serves as a reference for all rocks formed during the same time period.