GeologyRocks

Natural Selection

Differential reproductive success. Produces descent with modification, i.e. evolution.

Neomorphism

A diagenetic transformation of a mineral and itself or a polymorph, including differences in size and shape.

Neosome

A geometric element of a composite rock or mineral deposit, appearing to be younger than the main rock mass, for example the leucosomes in a migmatite are a neosome.

Nephelinite

A silica-undersaturated volcanic igneous rock containing nepheline and pyroxene.

Definition provided by: Tim Ivanic (University of Edinburgh)

Neutral theory of molecular evolution

Predicts that alleles are fixed at a constant rate for a given gene over long periods and that most molecular variation is selectively neutral.

Nomenclature

The method of naming species of animals and plants scientifically.

Nonconformity

An unconformity that exists between sedimentary rocks and metamorphic or igneous rocks when the sedimentary rock was deposited on the pre-existing, eroded metamorphic or igneous rock.

Normal Fault

A fault caused by extension.

Nuees Ardentes

See Pyroclastic Flows.