A Preliminary Luminescence Dating Of Modern Samples

Over the last few years luminescence dating has been improved considerably, both in the methods for the estimation of the equivalent dose, De (with the development of the single-aliquot regenerative-dose (SAR) protocol, Murray and Wintle, 2000 and MSAR protocol, Wang et. al., 2005a) and in the measurement facilities (B(?)tter-Jensen and Murray, 1999). Dating of young samples from a wide range of depositional environments were widely reported (Stokes and Rhodes, 1989 Ollerhead, 1994 Berger, 1995 Duller. 1996, Stokes, 2001; Jain, 2004). However, the dating of young samples is inherently problematic, as a relatively greater proportion of the natural signal can be affected by several complicated factors (e.g. partial bleaching, thermal transfer, etc.), which may lead to inaccurate De estimation.The main purpose of this work is to choose the modern sediments, considering partial bleaching of affecting optical luminescence signal carry out a preliminary experimental study, to find effective and reliable methods and process technology for dating young sediments.The used samples for luminescence dating are from depositional environment of modern sediments the conclusions are as follows:It is important to confirm and quantify the occurrence of all systematic errors in luminescence analyses. First laboratory equipment is quantitativly estimate of the measurement performance. Calibrating of Daybreak 1100 automatic TL / OSL measurement instrument is carried out by fine quartz to examine and quantify the effects of cross-irradiation beta source irradiation uplift arm uplifting three different locations of the radiation dose. Dose is added to the annealing fine quartz sample for a short-bleaching step through the initial dose to resume exploring Daybreak2200 type of measurement and analysis ceiling was 0.02±0.0005Gy dose. It is assumed that environmental samples dose rate is 3Gy/ka, the equipment can detect the minimum age of 7 years.On Beijing dust samples of the April 16, 2006, using SAR measurements of quartz minerals, it is found that the equivalent dose distribution is asymmetric. Possibly it is related with partial bleaching and the particle source, experimental measurement of the flow and other factors. When the samples using different pre-treatment process to get the equivalent dose values, the results show that the originals may contain some sun bleaching retreat to the material, or to the quartz feldspar mineral an outer membrane, resulting in sample particle deposition in the former have not been fully solved retreat; of different pre-treatment process samples.The work uses single-use film renewable France to observe the process of measuring the changes of the flu, The results show when using different pre-treatment process of dating luminescence signal change of the impact is not obvious. It is [post-IR] OSL flu luminescence signal changes affected more significantly.In Liangshan region of humid climate three modern samples are,collected. In the arid weather aera four modern samples in gully are collected and three modern sample in the Gez River bed .The results showed that upstream samples equivalent dose is far higher than the downstream sample, In such an environment downstream samples should be collecting preferently; by comparisons of its different size dose equivalent value, in a small gully sedimentary environment, regardless of region humid climate or arid areas, fine-grain may be more easily bleaching than coarse grain. The three samples of Gez River equivalent dose value increases with the size reduction, possibly due to poor vegetation cover, and very rapid the water flow. Coarse grain sample is sufficiently has bright and a greater probability than fine particles.Modern slope wash samples LEDL06 - 489 fine grain component measurement, The results show that fine-grain mixed minerals us ing SAR has more problems,for fine-grain quartz components used SAR measurements, by a variety of analysis methods the equivalent dose is about 0.17 Gy, Afterd the sample environment dose rate value is obtained , the sample has the approximate age of about 80yr. According to the results of the sample.It is Afterd the sample environment dose rate value is obtained, the sample has the approximate age of about 80yr. According to the results of the sample.It is suggested that for this type of sediment fine quartz is choosen to measured dose equivalent value.