HIGH-RESOLUTION OSL DATING OF A COASTAL SEDIMENT SEQUENCE FROM THE SOUTH YELLOW SEA
HIGH-RESOLUTION OSL DATING OF A COASTAL SEDIMENT SEQUENCE FROM THE SOUTH YELLOW SEA
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南黄海沿海沉积物序列的高分辨率光释光测年
DOI：
10.1515/geochr-2015-0044
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发表时间：
2016-02-01
期刊：
影响因子：
1.2
通讯作者：
Yin, Yong
中科院分区：
文献类型：
--
作者：
Gao, Lei;Long, Hao;Yin, Yong
南黄海海岸沉积物提供了区域陆海相互作用的记录。这项研究调查了光学测年的适用性，使用粗粒度的石英，提供了这些沉积物的年代。在长江三角洲北翼的西南岸线取取了一个150 m长的钻井岩心（YZ07）。总的来说，从YZ07岩心上部50 m提取的28个样品进行了调查。进行了预热平台试验和剂量回收试验。光激发发光（OSL）信号是石英的典型特征，且以快速组分为主。每个样品测量的等效剂量（Des）的扩散大体上与沉积前完全重置的OSL信号一致。OSL年龄一般随深度增加而增加，在岩心上部50 m处有24 ka沉积记录。年龄-深度关系揭示了两个不同的沉积时期：(1)末次盛冰期（LGM）至全新世早期（类似于24 ~ 8 ka），沉积非常缓慢甚至沉积中断；(2)全新世中晚期沉积速度非常快，约为6 m/ka（自8 ka以来）。推测LGM以来研究区内的沉积可能与海平面变化、三角洲形成和切谷填充作用有关。
The coastal sediments of the South Yellow Sea (SYS) provide a record of regional landsea interactions. This study investigated the applicability of optical dating, using coarse-grained quartz, to provide a chronology of these sediments. A 150-m-long drilling core (YZ07) was retrieved from the southwest coast of the SYS on the northern flank of the Yangtze River delta. Overall, 28 samples extracted from the upper 50 m of core YZ07 were investigated. Preheat plateau and dose recovery tests were conducted. The optically stimulated luminescence (OSL) signals were typical of quartz and they were dominated by fast components. The spread in measured equivalent doses (Des) for each sample was generally consistent with the OSL signals being fully reset before deposition. The OSL ages generally increased with depth and indicated a 24-ka sedimentary record for the upper 50 m of the core. The age-depth relationship revealed two distinct sedimentary periods: (1) very slow sedimentation or even a depositional hiatus from the last glacial maximum (LGM) to the early Holocene (similar to 24 to 8 ka); (2) very fast sedimentation at a rate of similar to 6 m/ka during the middle to late Holocene (since similar to 8 ka). It is speculated that sedimentation within the study area since the LGM might have been related to sea level change, delta initiation, and incised-valley fill processes.