OSL involves beaming sediment samples with blue, green or infrared light to determine how long ago minerals including quartz and feldspar were last exposed to daylight.
Samples subjected to such treatment may emit a luminescence whose intensity can be an indicator of how much radiation (in part from cosmic rays) the sample absorbed during its burial.
apparently by several Neanderthal children about 2-4 years old, judging by the prints?
during the Middle Paleolithic period about 135,000 years ago.
The older a sample is, the more luminescence it emits.
To determine age, a comparison is made between sediments with a known amount of added radiation and sample sediments that were affected naturally.
The chronology of its prehistoric inhabitation has been established through more than 50 radiocarbon dates derived mostly from charcoal samples collected from the remains of hearths.
s team found a trail of at least three hominid footprints left in the cave?The unassuming remains of a stone wall that once partly closed off the entrance to the prehistoric Theopetra Cave near Kalambaka, Thessaly, have recently been dated by specialists to about 21000 BC, making it the oldest known man-made construction in Greece and likely the world, according to a statement on March 22, 2010, by the Greek Ministry of Culture and Tourism.According to radio carbon dating, the date 23,000 BP (years before present) was determined by a pair of scientists, Nicholaos Zacharias and Ioannis Basiakos, at the Archaeometry Laboratory of the National Center for Scientific Research Demokritos, using a relatively new method of dating called Optically Stimulated Luminescence (OSL, see below).Analysis of carbonized plants and seeds has also begun to shed light on the inhabitants?Deposits of unbaked clay detected within the cave point to Upper Paleolithic exploitation or experimentation with the malleable material long before actual fired pottery began to appear in the early Neolithic era.
The cave, in a setting overlooking the Lithaios River, a tributary of the Pineios River, just 3 kilometers from the rock pillars and monasteries of Meteora, consists of a 500-square-meter rectangular chamber of which the entrance is 17 meters long by 3 meters high.