Age limits on Middle Pleistocene glacial sediments from OSL dating, north Norfolk, UK
Age limits on Middle Pleistocene glacial sediments from OSL dating, north Norfolk, UK
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DOI：
10.1016/j.quascirev.2008.02.013
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发表时间：
2008-07
影响因子：
4
通讯作者：
S. Pawley;R. Bailey;J. Rose;B. Moorlock;R. Hamblin;S. Booth;Jonathan R. Lee
中科院分区：
文献类型：
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作者：
S. Pawley;R. Bailey;J. Rose;B. Moorlock;R. Hamblin;S. Booth;Jonathan R. Lee
诺福克北部的低地地区保存了欧洲西北部中更新世冰川沉积的一些最好证据。尽管这些沉积物的重要性，有有限的年代控制，它是有争议的，他们是否属于一个单一的冰川作用，等同于盎格鲁冰川作用（海洋同位素阶段12），或代表沉积在一些中更新世冷阶段。为了建立该地区冰川作用的年代学，我们对18个冰川沉积相样品进行了光释光测年。粗粒石英砂样品的测量使用SAR（单等分再生剂量）协议。该地区沉积物中放射性同位素浓度低，使传统上接受的发光测年的年龄限制得以延长。剂量响应曲线的形式、预热平台试验和剂量恢复实验也表明，在这些样品中可以可靠地测量实验室剂量。年龄高估由于部分漂白被认为是微不足道的。OSL年龄表明，冰川沉积物研究期间MIS 12，而不是在不同的后MIS 12阶段沉积。
The lowland region of north Norfolk contains some of the best preserved evidence for glacial deposition during the Middle Pleistocene in northwest Europe. Despite the importance of these deposits, there is limited chronological control and it is debated whether they belong to a single glaciation, equated to the Anglian Glaciation (Marine Isotope Stage 12), or represent deposition over a number of Middle Pleistocene cold stages. In order to develop an improved chronology for glaciation in this region, we obtained 18 samples for optical stimulated luminescence (OSL) dating from glacial outwash facies. Samples of coarse-grained quartz sand were measured using the SAR (single aliquot regenerative-dose) protocol. The low radioactive isotope concentrations in sediments of this region enable the traditionally accepted age limit of luminescence dating to be extended. The form of the dose response curves, pre-heat plateaux tests, and dose recovery experiments also indicate that laboratory doses can be reliably measured in these samples. Age overestimation due to partial bleaching is thought to be insignificant. The OSL ages suggest that the glacial sediments studied were deposited during MIS 12 rather than in different post MIS 12 stages.