Index Fossil Definition An Index fossil, in the field of paleontology, refers to a fossil that identifies and dates the stratigraphic unit that it is observed to exist in. Index fossils can combine a wide geographic range. And they can really narrow down the classifications of most stratigraphic units.

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.

Runoff (R) The term “Runoff” (R) in hydrogeology and geology refers to the part of rainfall which accumulates on the ground surface and naturally forms into flowing streams.

Wing Dam or Wing Dike A “Wing Dam” or “Wing Dike” refers to a dam that intentionally retains a fraction of the width of a flowing water source. Unlike a conventional dam, a wind dam aims to divert the path of water flow. Additionally, a wing dike can control the velocity of water flow. For…

Dilatancy “Dilatancy” is the increase in the bulk volume of a soil substance during deformation. Dilatancy is caused by the change from a close-pack structure to an open-pack structure.