4.5.2 Polarity chronozone (polaritetskronosone)
4.5.2.1 Polarity chronozone is the fundamental polarity-chronostratigraphical unit. It consists of rocks and superficial deposits having a specific primary polarity that is valid globally. Polarity chronozones are erected following extensive documentation of the magnetopolar properties, lithostratigraphy, biostratigraphy, chronostratigraphy, correlation and age relationship of a unit (see Section 2.4).
A polarity chronozone can be divided into two or more polarity subchronozones (polaritetsunderkronosoner). Two or more polarity chronozones can be grouped in a higher-ranking unit called a polarity superchronozone (polaritetsoverkronosone) (Table 1).
4.5.2.2 Naming of polarity chronozones -- A polarity chronozone is named in accordance with the "general rules for naming and defining geological units" (Chap. 2). The complete formal name has three component parts. The first is a proper name, which is a geographical name from a type locality or type area. It is followed by a term denoting the type of polarity, normal (normal), reversed (revers), or mixed (blandet), and finally by the word "chronozone". The initial letters of all these words are capitalized in English, but written in lower case in Norwegian (see Section 4.1).
If the same geographical name is used for both a polarity zone and a polarity chronozone, the difference is marked in English by adding the adjectival ending "-an" or "-ian" to the geographical name of the polarity chronozone. Frequently used names which do not have a geographical origin can still be employed. Examples of this are "Brunhes" ("brunhes"), "Matuyama" ("matuyama"), "Gauss" ("gauss") and "Gilbert" ("gilbert"). The proper name can be used alone provided misunderstandings cannot arise.
Key reference: NACSN (1983).
