Optical resetting in large drainage basins: tests of zeroing assumptions using single-aliquot procedures
Optical resetting in large drainage basins: tests of zeroing assumptions using single-aliquot procedures
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DOI：
10.1016/s0277-3791(00)00045-7
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发表时间：
2001-12
影响因子：
4
通讯作者：
S. Stokes;H. Bray;M. Blum
中科院分区：
文献类型：
--
作者：
S. Stokes;H. Bray;M. Blum
在沉积物的运输和埋藏过程中，先前积累的电荷群的光学重置仍然是发光测年中的一个关键假设。河流沉积物尤其如此。我们已经测试了在河流环境中的漂白程度，通过应用单等分再生（SAR）等效剂量（DE）的测定技术，再加上部分漂白测试。在大多数情况下，从得克萨斯州科罗拉多河上的点坝复合体采集的样品显示出不完全漂白的证据。在这些情况下使用最小SAR DE导致估计的剩余年龄为c。100-300年在对沿着卢瓦尔河采集的推移质样品的SAR DE进行类似检查时，我们观察到有效等效剂量（De）从14、10.2和3.2的值单调下降（平均值、中位数和最小值）戈伊，在运输的第一公里中降至3.3、3.6和1.6戈伊，运输距离超过300 km时为0.2和0.0 Gy。我们观察到几乎没有影响的DEin的推移质引入的干支流，并得出结论，在大型河流系统的OSL的重置的可能性是更有效的，以前考虑的沉积物的回收时，系统铭记。
Optical resetting of previously accumulated charge populations at the time of transportation and burial of sediments remains a critical assumption in luminescence dating. This is particularly the case for fluvial sediments. We have tested the extent of bleaching in fluvial environments by applying the single-aliquot regeneration (SAR) equivalent dose (DE) determination technique coupled with tests for partial bleaching. In the majority of cases, samples collected from a point bar complex on the Colorado River, Texas exhibit evidence of incomplete bleaching. Use of the minimum SAR DEin these cases resulted in estimated residual ages of c. 100–300 years. In a similar examination of SAR DE's for bed load samples collected along the Loire River we observe a monotonic decrease in effective equivalent dose (De) from values of 14, 10.2 and 3.2 (mean, median and minimum) Gy at source, down to 3.3, 3.6 and 1.6Gy in the first kilometre of transportation, down to levels of 0.3, 0.2 and 0.0Gy for transportation distances exceeding 300km. We observed virtually no effect on the DEin the bed load of the introduction of trunk tributary streams and conclude that the likelihood of resetting of OSL in large fluvial systems is somewhat more effective that previously considered when the recycling of sediments down the system are borne in mind.