Chronozone


chronozone

[krän·ə‚zōn] (geology) A formal time-stratigraphic unit used to specify strata equivalent in time span to a zone in another type of classification, for example, a biostratigraphic zone. Also known as chronostratigraphic zone. The smallest subdivision of chronostratigraphic units, below stage, composed of rocks formed during a chron of geologic time.

Chronozone

 

the zone of the general stratigraphic scale below the stage. A chronozone may be traced in rock strata of different lithological compositions, where the typical complex of fossil organisms may change considerably. It differs from the biostratigraphic zone, whose paleontological features remain constant. The term “chronozone” was introduced in 1961 by the Norwegian geologist G. Henningsmoen. (SeeSTRATIGRAPHY.)