A Complete Terrestrial Radiocarbon Record for 11.2 to 52.8 kyr B.P.
A Complete Terrestrial Radiocarbon Record for 11.2 to 52.8 kyr B.P.
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DOI：
10.1126/science.1226660
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发表时间：
2012-10
期刊：
影响因子：
56.9
通讯作者：
C. Bronk Ramsey;R. Staff;C. Bryant;F. Brock;H. Kitagawa;J. van der Plicht;G. Schlolaut;M. Marshall;A. Brauer;H. Lamb;R. L. Payne;P. Tarasov;T. Haraguchi;K. Gotanda;H. Yonenobu;Y. Yokoyama;R. Tada;T. Nakagawa
中科院分区：
文献类型：
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作者：
C. Bronk Ramsey;R. Staff;C. Bryant;F. Brock;H. Kitagawa;J. van der Plicht;G. Schlolaut;M. Marshall;A. Brauer;H. Lamb;R. L. Payne;P. Tarasov;T. Haraguchi;K. Gotanda;H. Yonenobu;Y. Yokoyama;R. Tada;T. Nakagawa
碳定年
放射性碳定年是确定含碳且年龄小于约50000年（该方法的精度极限）的样本年龄的最佳方法。然而，有几个因素使这种年龄测定变得复杂，其中一些最重要的因素包括大气中¹⁴C产生的变异性（这会影响其放射性碳存量来自大气二氧化碳的有机样本）、海洋表层储库效应（这会影响从海水中获取放射性碳特征的海洋样本）以及可变的死碳分数效应（这会影响从地下水中获取碳的洞穴堆积物）。布朗克·拉姆齐等人（第370页；见赖默的观点）避免了做出此类假设的需要，他们报告了日本诹访湖沉积物的¹⁴C结果。对具有年代可考的年层状沉积物中的陆地植物大化石进行分析，得出了直至52800年前整个可测量区间内大气放射性碳的直接记录。对日本诹访湖样本的放射性碳测量将¹⁴C时间尺度追溯到50000多年前。
放射性碳（¹⁴C）为确定年龄达约50000年的含碳物质的年代提供了一种方法，它也是全球碳循环的一个重要示踪剂。然而，由于缺乏能反映距今12500年前（kyr B.P.）之前大气¹⁴C的全面记录，限制了对末次冰期样本进行放射性碳定年的应用。在此，我们报告了日本诹访湖（北纬35°35′，东经135°53′）的¹⁴C结果，它提供了陆地放射性碳直至¹⁴C方法当前极限的全面记录。我们在这项工作中提出的时间尺度使得诹访湖古气候数据能够与其他陆地气候记录进行直接比较，并提供了全球大气和区域海洋放射性碳水平之间联系的信息。
Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain carbon and that are younger than ∼50,000 years, the limit of precision for the method. There are several factors that complicate such age determinations, however, some of the most important of which include variability of the 14C production in the atmosphere (which affects organic samples whose radiocarbon inventories are derived from atmospheric CO2), surface ocean reservoir effects (which affect marine samples that acquire their radiocarbon signatures from seawater), and variable dead carbon fraction effects (which affect speleothems that derive their carbon from groundwaters). Bronk Ramsey et al. (p. 370; see the Perspective by Reimer) avoid the need to make such assumptions, reporting the 14C results of sediments from Lake Suigetsu, Japan. Analysis of terrestrial plant macrofossils in annually layered datable sediments yielded a direct record of atmospheric radiocarbon for the entire measurable interval up to 52.8 thousand years ago. Radiocarbon measurements of samples from Lake Suigetsu, Japan, extend the 14C time scale back to more than 50,000 years ago. Radiocarbon (14C) provides a way to date material that contains carbon with an age up to ~50,000 years and is also an important tracer of the global carbon cycle. However, the lack of a comprehensive record reflecting atmospheric 14C prior to 12.5 thousand years before the present (kyr B.P.) has limited the application of radiocarbon dating of samples from the Last Glacial period. Here, we report 14C results from Lake Suigetsu, Japan (35°35′N, 135°53′E), which provide a comprehensive record of terrestrial radiocarbon to the present limit of the 14C method. The time scale we present in this work allows direct comparison of Lake Suigetsu paleoclimatic data with other terrestrial climatic records and gives information on the connection between global atmospheric and regional marine radiocarbon levels.