Archaeological scientific dating techniques
The most common archaeological methods, however, involve the slow removal of relics, remains and other evidence from sites that have been buried for hundreds or thousands of years.This technique, called excavation, is often done by hand and involves rigorously scientific protocols.
It is most useful for minerals older than 100,000 years and can reach way back into the geological past.Dates above and below a location provide minimum and maximum age determinations according to the law of superimposition.Thermoluminescence is a similar technique to optical dating, but uses heat instead of light to stimulate the minerals.Working out how old archaeological remains are is a vital part of archaeology.Scientific dating has confirmed the long residence of Aboriginal people in Australia.In the 21st century, the different methods of archaeology include high-tech analysis of archaeological sites with magnetic equipment, electrical sensors, and even satellite photography.
Specialized methods such as underwater archaeology, urban archaeology and rescue archaeology are employed for sites in unusual locations.
This 'law of superimposition' works in the well-defined layers of the Willandra lunettes, but only dates objects as younger or older than adjacent layers.
To determine the year age (absolute age) of an object, a number of chemical and radioactive techniques can be used.
For sites located within modern cities, for example, urban archaeology is employed; this method involves disturbing the surrounding businesses and homes as little as possible, and coordinating efforts with city governments to protect the site during survey and excavation.
If a site is in imminent danger of being destroyed by development, archaeologists will use a more rapid method called rescue archaeology.
Optical dating, also known as optically stimulated luminescence (OSL), dates the last time mineral sediments (usually quartz or feldspar grains ) were exposed to sunlight.