“Test” Definition in Paleontology In the field of paleontology, a subsidiary of geology, the term “test” refers to the external hard part of an invertebrate.

Facies Facies: In the field of geology, the term “facies” represents a mappable, areally restricted part of a rock body that has different fossils or lithology from other contiguous beds deposited at the same time.

Surface-Wave Magnitude “Surface-Wave Magnitude” is the magnitude of an earthquake that scientists estimate using measurements of the amplitude of surface waves.

Well Graded Soil Well Graded: In the soil classification process of geology, well graded soil represents a sedimentary soil sample that fully displays all of the possible grain sizes for that soil classification, in accordance with the Unified Soil Classification System (USCS). For example, a well graded sand (SW) comprises fine, medium, and coarse grains…

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.

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.