Surface water conditions and calcium carbonate preservation in the Fram Strait during marine isotope stage 2, 28.8–15.4 kyr
Surface water conditions and calcium carbonate preservation in the Fram Strait during marine isotope stage 2, 28.8–15.4 kyr
复制标题
DOI：
10.1002/2012pa002448
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Katarzyna Zamelczyk;T. L. Rasmussen;K. Husum;F. Godtliebsen;M. Hald
中科院分区：
文献类型：
--
作者：
Katarzyna Zamelczyk;T. L. Rasmussen;K. Husum;F. Godtliebsen;M. Hald
[1]我们提出了高分辨率的碳酸钙保存记录以及弗拉姆海峡浮游有孔虫的分布模式。记录覆盖了海洋同位素阶段(MIS2)，28.8至15.4KYR，包括末次冰盛期(LGM)和数十年时间分辨率的早期冰川消退。调查的依据是浮游有孔虫的分布模式、稳定同位素、厚皮新球藻的平均壳重、浮游壳的破碎程度、CaCO3含量以及地球化学和沉积学数据。溶解指标表明，在末次盛冰期期间，碳酸钙在~28.8-27.2、~24.1-23.2和~16.6-15.4Kyr处的保存明显减少，并有一些短暂的持续期(<；300年)。伴随着这些时期的是亚极地浮游有孔虫标本的显著减少，表明北极表面水团向南扩张。亚极地有孔虫物种丰度高的时间延长和碳酸钙的保存良好归因于大西洋水团的影响增加，这种影响似乎贯穿于MIS2的大部分地区。与全新世(MIS1)的壳重记录相比，MIS2的保存总体上更好，即使在溶解事件中也是如此。这可能是当时大气中二氧化碳浓度较低的反映。
[1] We present a high-resolution record of calcium carbonate preservation alongside the distribution pattern of planktic foraminifera from the Fram Strait. The record covers the marine isotope stage (MIS) 2, 28.8 to 15.4 kyr, including the Last Glacial Maximum (LGM) and the early deglaciation in multidecadal temporal resolution. The investigation is based on the distribution patterns of planktic foraminifera, stable isotopes, mean shell weight of Neogloboquadrina pachyderma, the degree of fragmentation of planktic shells, CaCO3 content, and geochemical and sedimentological data. The dissolution proxies indicate long-lasting periods of markedly reduced preservation of calcium carbonate at ~28.8–27.2, ~24.1–23.2, and ~16.6–15.4 kyr in addition to a number of short-lasting periods (< 300 year) during the LGM. These periods are accompanied by a simultaneous and significant reduction in specimens of subpolar planktic foraminifera indicating a southward expansion of Arctic surface water masses. Prolonged periods with high abundances of subpolar foraminiferal species and good preservation of calcium carbonate are attributed to increased influence of Atlantic water masses, which appears to persist throughout most of the MIS 2. Comparison to Holocene (MIS 1) shell weight records shows that the preservation during MIS 2 was overall better, even during the events of dissolution. This was probably a reflection of the low concentration of atmospheric CO2 at the time.