The thermoluminescence TL properties of plagioclase separates from 10 independently dated alkalic basalts from the Hawaiian Islands were studied for the purpose of developing a TL dating method for young volcanic rocks. The samples range in composition from alkalic olivine basalt to trachyte and in age from years to 3. The TL process in basaltic plagioclase appears to involve the production of structural defects by radioactive decay particles, as well as the filling of traps associated with these defects with excited electrons. The ratios of natural to artificial TL for the samples up to , years old increase at a uniform exponential rate; the ratios for samples greater than 1 m. The equation for the best fit line through a plot of the TL ratios versus known age for the younger samples constitutes a TL age equation suitable for assigning TL ages to other samples of similar origin and chemical composition.
Archaeological Dating: Stratigraphy and Seriation
Absolute dating - Wikipedia
Vandermeersch, B. McCown, T. Howells, W. Bar-Yosef, O. Ronen, A. Valladas, H.
THE oldest secure date for human occupation in Greater Australia is 40kyr from eastern Papua New Guinea 1 , whereas slightly younger dates have been reported from southern Australia 2. We now report thermoluminescence TL dates that suggest the arrival of people between 50 and 60 kyr in northern Australia. TL dates were obtained from sandy footslope deposits at two former occupation sites that yielded a range of stone artefacts in their primary depositional setting. Artefacts terminated mid-way down one profile, which had a basal age of about kyr.
Luminescence dating including thermoluminescence and optically stimulated luminescence is a type of dating methodology that measures the amount of light emitted from energy stored in certain rock types and derived soils to obtain an absolute date for a specific event that occurred in the past. The method is a direct dating technique , meaning that the amount of energy emitted is a direct result of the event being measured. Better still, unlike radiocarbon dating , the effect luminescence dating measures increases with time. As a result, there is no upper date limit set by the sensitivity of the method itself, although other factors may limit the method's feasibility. To put it simply, certain minerals quartz, feldspar, and calcite , store energy from the sun at a known rate.