14C Dating of Humic Acids from Bronze and Iron Age Plant Remains from the Eastern Mediterranean
14C Dating of Humic Acids from Bronze and Iron Age Plant Remains from the Eastern Mediterranean
复制标题
东地中海青铜和铁器时代植物遗骸中腐植酸的 14C 年代测定
DOI：
10.1017/s003382220005774x
复制
发表时间：
2013
期刊：
影响因子：
8.3
通讯作者：
F. Höflmayer
中科院分区：
文献类型：
--
作者：
E. Wild;P. Steier;P. Fischer;F. Höflmayer
植物残骸的放射性碳测年往往很困难，因为在ABA前处理的碱性步骤中，样品会完全溶解。在维拉实验室，当来自地中海东部的大量青铜和早期铁器时代样本在特别研究计划SCIEM2000的过程中以及在与专注于该地区和时间段的考古学家的其他合作中被确定年代时，这个问题经常被遇到。对于这些样品，只有14C年龄测定腐植酸部分是可能的。来自考古样本的腐植酸总是被评估为14C测年的第二选择材料。假设~(14)C年龄可能受到来自其他(较年轻的)有机物质的腐植酸的存在的影响，例如，来自样品上方的土层。因此，在确定腐植酸的日期时，对日期的核实至关重要。为了满足这一基本要求，我们在一段时间前开始对烧焦的种子、木材和木炭样品的各部分进行测年，即ABA处理后的残留物和从碱性步骤中提取的样品中的腐植酸。比较结果表明，在所调查的东地中海考古遗址中，有50个(52个)腐植酸测年结果与各自经ABA处理的样品的14C测年结果一致。对年龄差异的统计分析得出的结论是，提取的腐植酸来自样品本身或来自同时代的物质，并未受到不同年龄的外来物质的明显污染。
Radiocarbon dating of plant remains is often difficult due to the complete dissolution of the samples in the alkaline step of the ABA pretreatment. At the VERA laboratory, this problem was encountered frequently when numerous Bronze and Early Iron Age samples from the eastern Mediterranean were dated in the course of the special research program SCIEM2000 and in other collaborations with archaeologists focused on that area and time period. For these samples, only a 14C age determination of the humic acid fraction was possible. Humic acids from archaeological samples are always assessed as a second-choice material for 14C dating. It is assumed that the 14C ages may be affected by the presence of humic acids originating from other (younger) organic material, e.g. from soil horizons located above a sample. Therefore, when humic acids are dated a verification of the dates is crucial. To address this basic requirement, we started some time ago to date both fractions of charred seeds, wood, and charcoal samples whenever available, i.e. the residue after the ABA treatment and the humic acids extracted from the samples in the alkaline step. The results of this comparison showed that for the investigated eastern Mediterranean archaeological sites, 50 (out of 52) humic acid dates were in agreement with the 14C dates of the respective ABA-treated samples. Statistical analysis of the age differences leads to the conclusion that the extracted humic acids originated from the samples themselves or from contemporaneous material and were not appreciably contaminated by extraneous material of different age.