Osl dating ppt


Our data confirm that OSL dating using widely distributed fine-grain quartz has great potential for dating deep-sea sediments.Because luminescence methods use clastic materials, they do not depend on the presence of biogenic carbonate.by comparison with marine oxygen isotope stratigraphy where possible, (2) describe changes in sedimentation rate through time, and (3) test whether it is possible to date back to marine isotope stage 5e (MIS 5e).We show here that optical dating of fine grains of quartz from the central Sea of Okhotsk is able to provide an accurate and precise chronology for the reconstruction of the palaeoceanic and palaeoclimatic environment at our site.It is useful to geologists and archaeologists who want to know when such an event occurred.It uses various methods to stimulate and measure luminescence.As a result it is now likely that we can establish a chronology in regions of the ocean that were previously undatable.Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating.

A clear change in sedimentation rate is identified: between ∼139 and 110 ka, the sedimentation rate was ∼0.09 m/ka, but then from ∼110 to 15 ka, the sedimentation rate decreases to a constant value of ∼0.04 m/ka.The radiation causes charge to remain within the grains in structurally unstable "electron traps".The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried.All sediments and soils contain trace amounts of radioactive isotopes of elements such as potassium, uranium, thorium, and rubidium.These slowly decay over time and the ionizing radiation they produce is absorbed by mineral grains in the sediments such as quartz and potassium feldspar.Marine sediments contain important archives of past ocean and climate changes, but at high latitudes the absence of carbonate has prevented the construction of accurate chronological models.

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