Dating organic material
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.
SYNONYMS OR RELATED TERMS: archaeomagnetic intensity dating, archaeomagnetism, palaeointensity dating, archaeomagnetic age determination CATEGORY: technique DEFINITION: A chronometric method used to date objects containing magnetic materials -- especially for buried undisturbed features such as pottery kilns, earthen fireplaces, and brick walls -- which can be compared to known schedules of past magnetic alignments within a region and fluctuations in the earth's magnetic field.
The date on a coin is an absolute date, as are AD 1492 or 501 in which the proportion of carbon isotopes is counted directly (as contrasted with the indirect Geiger counter method) using an accelerator mass spectrometer.
The method drastically reduces the quantity of datable material required.
The technique is based on the principle that cations of certain elements are more soluble than others; they leach out of rock varnish more rapidly than the less soluble elements, and their concentration decreases with time.
A cation is an ion carrying a positive charge which moves toward the negative electrode/cathode during electrolysis.
Search for dating organic material:
Clay and rocks contain magnetic minerals and when heated above a certain temperature, the magnetism is destroyed.