A paleomagnetic approach toward refining Holocene radiocarbon-based chronologies: Paleoceanographic records from the north Iceland (MD99-2269) and east Greenland (MD99-2322) margins
A paleomagnetic approach toward refining Holocene radiocarbon-based chronologies: Paleoceanographic records from the north Iceland (MD99-2269) and east Greenland (MD99-2322) margins
复制标题
DOI：
10.1029/2006pa001285
复制
发表时间：
2007-02
期刊：
影响因子：
--
通讯作者：
J. Stoner;A. Jennings;G. B. Kristjánsdóttir;G. Dunhill;J. Andrews;J. Hardardóttir
中科院分区：
文献类型：
--
作者：
J. Stoner;A. Jennings;G. B. Kristjánsdóttir;G. Dunhill;J. Andrews;J. Hardardóttir
[1]我们报告的相互校准的古地磁长期变化（PSV）和放射性碳测年的两个扩大的冰后期沉积物芯从地理上接近，但海洋和沉积对比设置。其目的是改善相对相关性和时序，可以实现与任何一种方法单独。MD 99 -2269岩芯取自冰岛北部大陆架的Hunafloaall海槽。MD 99 -2322岩芯采自格陵兰东部边缘的Kangerlussuaq槽。这两个岩芯都有很好的年代测定，2269和2322岩芯分别有27和20个加速器质谱14 C年代测定。对u通道样品进行的古地磁测量记录了强、稳定的单分量磁化。使用每个岩心的独立校准的放射性碳年龄模型显示了古地磁倾角和磁倾角记录的时间相似性。PSV记录的对比表明，两个岩心之间的相对相关性可以进一步提高。从深度域开始，调整或添加最初基于校准的14 C日期的连接点，以最大化PSV相关性。从两个核心的放射性碳日期，然后结合在一个共同的深度尺度产生的PSV相关。相关性的支持来自日期的一致交织，Saksunarvatn火山灰的正确对齐，以及古海洋学代用数据（碳酸盐百分比）的相关性改善。这些结果表明，PSV相关与14 C日期可以提高相对相关性，也可以通过允许从不同的地层序列的日期被组合成一个单一的，更高的测年密度，年龄-深度模型的区域年表。
[1] We report the intercalibration of paleomagnetic secular variation (PSV) and radiocarbon dates of two expanded postglacial sediment cores from geographically proximal, but oceanographically and sedimentologically contrasting settings. The objective is to improve relative correlation and chronology over what can be achieved with either method alone. Core MD99-2269 was taken from the Hunafloaall Trough on the north Iceland shelf. Core MD99-2322 was collected from the Kangerlussuaq Trough on the east Greenland margin. Both cores are well dated, with 27 and 20 accelerator mass spectrometry 14C dates for cores 2269 and 2322, respectively. Paleomagnetic measurements made on u channel samples document a strong, stable, single-component magnetization. The temporal similarities of paleomagnetic inclination and declination records are shown using each core's independent calibrated radiocarbon age model. Comparison of the PSV records reveals that the relative correlation between the two cores could be further improved. Starting in the depth domain, tie points initially based on calibrated 14C dates are either adjusted or added to maximize PSV correlations. Radiocarbon dates from both cores are then combined on a common depth scale resulting from the PSV correlation. Support for the correlation comes from the consistent interweaving of dates, correct alignment of the Saksunarvatn tephra, and the improved correlation of paleoceanographic proxy data (percent carbonate). These results demonstrate that PSV correlation used in conjunction with 14C dates can improve relative correlation and also regional chronologies by allowing dates from various stratigraphic sequences to be combined into a single, higher dating density, age-to-depth model.