Comparison of varve and 14C chronologies from Steel Lake, Minnesota, USA
Comparison of varve and 14C chronologies from Steel Lake, Minnesota, USA
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美国明尼苏达州 Steel Lake 的 varve 和 14C 年表比较
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发表时间：
2005
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通讯作者：
Feng Sheng Hul
中科院分区：
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作者：
Jian Tlan;T. Brown;Feng Sheng Hul
年积层沉积物（纹管）是获取高质量古环境记录的有效手段。然而，一个纹层年表的强度可能会受到许多因素的影响，如缺失的纹层，模糊的层压和人为计数错误。我们评估的质量，在过去的三千年，从钢湖，明尼苏达州，通过比较与9 AMS 14 C日期陆生植物宏化石从同一个核心的纹层年表。这些比较揭示了总体8.4%的差异，主要是因为在两个地层间隔内缺失/不可数的纹层，其特征是碳酸盐浓度低和模糊的纹层。应用适当的校正因子，这两个时间间隔的结果在出色的协议之间的纹和14 C年表。这些结果，连同其他纹层研究，表明，一个独立的年龄测定方法，如14 C测年，通常是必要的验证，并可能正确，纹层年表。
Annually laminated sediments (varves) offer an effective means of acquiring high-quality palaeoenvironmental records. However, the strength of a varve chronology can be compromised by a number of factors, such as missing varves, ambiguous laminations and human counting error. We assess the quality of a varve chronology for the last three millennia from Steel Lake, Minnesota, through comparisons with nine AMS 14C dates on terrestrial plant macrofossils from the same core. These comparisons revealed an overall 8.4% discrepancy, primarily because of missing/uncountable varves within two stratigraphic intervals characterized by low carbonate concentrations and obscure laminations. Application of appropriate correction factors to these two intervals results in excellent agreement between the varve and 14C chronologies. These results, together with other varve studies, demonstrate that an independent age-determination method, such as 14C dating, is usually necessary to verify, and potentially correct, varve chronologies.