The basis for the technique is the fact that almost all amino acids change from optically active to optically passive compounds (racemize) over a period of time.
Aspartic acid is the compound most often used because it has a of 15,000-20,000 years and allows dates from 5,000-100,000 years to be calculated.
It is generally a raised area above the rest of the city where the most important sacred and secular buildings are brought together.
The buildings on the Athenian Acropolis were important for trade and worship.
However, racemization is very much affected by environmental factors such as temperature change.
Dating methods in archaeology establish the time and sequence of events that created archaeological deposits and layers, called strata, within those deposits. Absolute dating relies on biological, chemical (radiometric), geological/electromagnetic, or historical investigation to obtain the date range of a deposit.
This method can give archaeologists an indication of the age of the artifacts in all Absolute dating methods can give an estimate of the real calendar age of an artifact or site.
There are several absolute dating methods that archaeologists can use, including radiocarbon dating and potassium argon dating.potassium) decays into argon over time, so the age of certain rocks or minerals can be discovered by measuring the amount of argon they contain.
Aerial Photography - The various techniques of taking photographs of natural or cultural features from the air, using balloons, airplanes, satellites, and other sources, in order to study the features in their entirety from a top-down (bird's eye) view.
Aerial Reconnaissance - The technique of searching for sites and features, both cultural and natural, from the air, often using aerial photography or the human eye.
The method drastically reduces the quantity of datable material required.
SYNONYMS OR RELATED TERMS: amino-acid dating; aminostratigraphy; amino-acid racemization, amino acid racemization CATEGORY: technique DEFINITION: A method of absolute (chronometric) dating which is hoped to fill the gap between radiocarbon dates and potassium-argon dates.
This method is useful for archaeologists working in areas where volcanic eruptions have left layers of ash above and below an archaeological deposit.