who was brad pitt dating in 1994 - Optically stimulated luminescence dating of young sediments a review

These dates are internally consistent and fit well with previously published radiocarbon ages obtained from the same deposits.In addition, when the technique was applied to a modern beach, it resulted in an age of zero.Le déclin des labours à partir des années 1915 diminua la fourniture sédimentaire alors que le développement de l’urbanisation après 1950 augmenta l’énergie des crues (rejets d’eaux pluviales et de déversoirs d’orages), causant l’incision actuelle qui débuta vers 1975.

optically stimulated luminescence dating of young sediments a review-72optically stimulated luminescence dating of young sediments a review-47optically stimulated luminescence dating of young sediments a review-48

Optically stimulated luminescence (OSL) dating of perennially frozen loess was tested on quartz grains extracted from deposits associated with the late Pleistocene Dawson tephra in western Yukon Territory, Canada.

OSL samples were obtained from ice-rich loess bracketing the Dawson tephra, while radiocarbon (C) samples were collected from the bulk sediments directly underlying the tephra and from a ground-squirrel burrow 2.7 m below the tephra.

We therefore recommend analysis of individual grains to overcome the age-shortfall from multi-grain analysis of these and similar samples of quartz.

Most current methods of reconstructing past sea levels within Antarctica rely on radiocarbon dating.

Here we report the OSL characteristics and ages of the extracted quartz grains, as well as additional radiocarbon ages for samples described in Froese [2002.

Age and significance of the late Pleistocene Dawson tephra in eastern Beringia. Seasonality of the late Pleistocene Dawson tephra and exceptional preservation of a buried riparian surface in central Yukon Territory, Canada. We refine the time of Dawson tephra deposition to between 25,420±70 and 25,290±80 C a BP.The single-aliquot regenerative-dose protocol was applied to multi-grain aliquots and single grains to obtain equivalent dose (, and yielded OSL ages of 28±5 and 30±4 ka for the samples taken from above and below the Dawson tephra, respectively.Examination of individual grains with differing luminescence behaviors showed that a significant number of the measured quartz grains exhibited anomalous luminescence properties that would have compromised the results obtained from multi-grain aliquots.From this data a complex deposition and incision history is constructed for the last 500 years.It is concluded that sediment deposition was mainly forced by sediment supply from ploughing areas.However, radiocarbon dating is limited by the availability of material for dating and problems inherent with radiocarbon reservoirs in Antarctic marine systems.

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