chronn.

Brit.

/krɒn/, U.S.

/krɑn/

Origin: Formed within English, by clipping or shortening. Etymon: chronozone n.

Etymology: Shortened < chronozone n.Compare the following earlier proposals of chron ( < ancient Greek χρόνος time: see chronic adj.) as a term for a period of geological time, neither of which met with acceptance:1901 H. S. Williams in Jrnl. Geol. (Chicago) 9 583 Terms of the Bionic Time Scale. Chron.—An indefinite division of geological time.1940 A. H. Sutton in Bull. Geol. Soc. Amer. 51 1397 In order to keep alive the effort to attain general agreement on a satisfactory dual nomenclature of time and stratigraphic units, the following classification is proposed: era—sequence; period—system; epoch—series; subepoch—subseries; chron—group; stage—formation; and substage—member.

Geology.

A period of time between two geological events, esp. reversals of the polarity of the earth's magnetic field. Cf. chronozone n.

ΚΠ

1967 Proc. Geol. Soc. Mar. 83 Chron (new term): the smallest standard division of the Chronomeric Standard Scale; a component part of an Age; corresponds to a Standard Chronozone.

1977 Jrnl. Paleontol. 51 992 Miller (1968), divided the Niobrara Formation in Kansas into eight divisions (chrons) largely based on Inoceramidae and Ostreidae, the only common benthonic molluscan families.

1989 Nature 30 Nov. 526/1 The boundary is marked by a distinct iridium anomaly in conjunction with the biostratigraphically placed boundary near the top of chron 29R.

2006 D. H. Erwin Extinction iii. 94 One of these is known as the Permo-Carboniferous reversed polarity superchron (a chron being a single interval of magnetic polarity, and a superchron a longer interval of stable polarity).

This is a new entry (OED Third Edition, September 2017; most recently modified version published online March 2022).

单词	chron
释义	chronn. Brit. /krɒn/, U.S. /krɑn/ Origin: Formed within English, by clipping or shortening. Etymon: chronozone n. Etymology: Shortened < chronozone n.Compare the following earlier proposals of chron ( < ancient Greek χρόνος time: see chronic adj.) as a term for a period of geological time, neither of which met with acceptance:1901 H. S. Williams in Jrnl. Geol. (Chicago) 9 583 Terms of the Bionic Time Scale. Chron.—An indefinite division of geological time.1940 A. H. Sutton in Bull. Geol. Soc. Amer. 51 1397 In order to keep alive the effort to attain general agreement on a satisfactory dual nomenclature of time and stratigraphic units, the following classification is proposed: era—sequence; period—system; epoch—series; subepoch—subseries; chron—group; stage—formation; and substage—member. Geology. A period of time between two geological events, esp. reversals of the polarity of the earth's magnetic field. Cf. chronozone n. ΚΠ 1967 Proc. Geol. Soc. Mar. 83 Chron (new term): the smallest standard division of the Chronomeric Standard Scale; a component part of an Age; corresponds to a Standard Chronozone. 1977 Jrnl. Paleontol. 51 992 Miller (1968), divided the Niobrara Formation in Kansas into eight divisions (chrons) largely based on Inoceramidae and Ostreidae, the only common benthonic molluscan families. 1989 Nature 30 Nov. 526/1 The boundary is marked by a distinct iridium anomaly in conjunction with the biostratigraphically placed boundary near the top of chron 29R. 2006 D. H. Erwin Extinction iii. 94 One of these is known as the Permo-Carboniferous reversed polarity superchron (a chron being a single interval of magnetic polarity, and a superchron a longer interval of stable polarity). This is a new entry (OED Third Edition, September 2017; most recently modified version published online March 2022). < n.1967
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