SYNONYMS OR RELATED TERMS: chronometric dating; absolute dates; absolute chronology; absolute age determination (antonym: relative dating)CATEGORY: chronology; technique DEFINITION: The determination of age with reference to a specific time scale, such as a fixed calendrical system or in years before present (B.
P., BP), based on measurable physical and chemical qualities or historical associations such as coins and written records.
The date on a coin is an absolute date, as are AD 1492 or 501 SYNONYMS OR RELATED TERMS: absolute dating; chronometry CATEGORY: technique DEFINITION: Any technique of dating that relies on chronological measurement such as calendars, radiocarbon dates, etc.
and which give the result in calendar years before the present, or B. Most of these techniques produce results with a techniques do not.
Among the most useful chronometric dating techniques are radiocarbon dating, potassium argon dating, and thermoluminescence dating.
SYNONYMS OR RELATED TERMS: chronology CATEGORY: technique DEFINITION: The process by which an archaeologist determines dates for objects, deposits, buildings, etc., in an attempt to situate a given phenomenon in time., in which figures in solar years (often with some necessary margin of error) can be applied to a particular event.Unless tied to historical records, dating by archaeological methods can only be relative -- such as stratigraphy, typology, , fluorine and nitrogen test, and radiometric assay.Other methods include: coin dating, seriation, and amino-acid racemization.The methods have varying applications, accuracy, range, and cost.Many new techniques are being developed and tested.CATEGORY: technique DEFINITION: Borings taken from the Arctic and Antarctic polar ice caps, containing layers of compacted ice, useful for the reconstruction of paleoenvironments and paleoclimatology and as a method of .Continuous cores, sometimes taken to the bedrock below, allow the sampling of an ice sheet through its entire history of accumulation.Because there is no melting, the layered structure of the ice preserves a continuous record of snow accumulation and chemistry, air temperature and chemistry, and fallout from volcanic, terrestrial, marine, cosmic, and man-made sources.Actual samples of ancient atmospheres are trapped in air bubbles within the ice. CATEGORY: feature DEFINITION: A pattern of parallel ridges resulting from the plowing of strip fields in medieval and later open field systems.The fossilized remains of ancient plowmarks are a common sight in England, having the appearance of long, rounded parallel ridges with alternating ditches.