“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.

Twinning Definition Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

Provenance Provenance: In the field of geology, and the branch of geomorphology, the term “provenance” means the place of origin from which the constituent materials of sedimentary rock or facies are derived.

Petroleum Extraction Well (Oil Well) Petroleum Extraction Well (Oil Well): A petroleum extraction well, or an oil well, is a deep borehole or shaft sunk into the Earth for the exploration of oil or gas. Additionally, injection wells are often drilled to inject fluids or gas for stimulating oil recovery, re-pressurizing or pressure maintenance of…

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

Potentiometric Surface The term “Potentiometric Surface” means the hydrogeological surface that represents the total hydraulic head of groundwater from a confined aquifer or semi-confined aquifer that’s under pressure. The Potentiometric Surface of an aquifer is defined by the level to which water will rise in a groundwater monitoring well (that’s exclusively screened within said aquifer).