Optically stimulated luminescence dating
Following the natural zeroing event and subsequent burial, the natural minerals begin luminescence acquisition afresh from the ionizing radiation (alpha, beta and gamma) constantly provided by the decay of radioactive elements (U238, Th232, K40, Rb) present in the sediments and also from the cosmic rays.
For calculating the age, the radiation energy stored in the mineral (known as Paleodose) and the annual radioactivity rate (annual dose) from the surrounding sediments has to be calculated.
A) Optically Stimulated Luminescence (OSL) Dating a) Blue Light Stimulated Luminescence (BLSL) Dating using Blue light emitting diodes b) Infra-red Stimulated Luminescence (IRSL) Dating using infrared diodes Luminescence dating is based on the principle that certain naturally occurring minerals (e.g.
Den tredje episoden var för ca 1900 - 1700 år sedan, vid romartidens klimatoptimum.The time elapsed since sedimentation, i.e., Age = Paleodose Annual Dose In practice, the paleodose is calculated by measuring the luminescence intensity in the natural mineral and regenerate the equivalent luminescence intensity by artificial radiation dose from a calibrated beta source attached to the TL/OSL instrument.For calculating the annual dose rate, the elemental concentration of U, Th and K (by XRF or ICP-MS) in the sediment and water content in the sediment are required.Both coarse- and fine-grained material can be used for dating.
Wiley Online Library requires cookies for authentication and use of other site features; therefore, cookies must be enabled to browse the site.Resultaten visar att det förekommit fem episoder av flygsandavsättning.