Chronostratigraphy of the 600,000 year old continental record of Lake Van (Turkey)
Chronostratigraphy of the 600,000 year old continental record of Lake Van (Turkey)
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DOI：
10.1016/j.quascirev.2014.04.008
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发表时间：
2014-11
影响因子：
4
通讯作者：
M. Stockhecke;O. Kwiecien;L. Vigliotti;F. Anselmetti;J. Beer;M. Çağatay;J. Channell;R. Kipfer;J. Lachner;T. Litt;N. Pickarski;M. Sturm
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文献类型：
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作者：
M. Stockhecke;O. Kwiecien;L. Vigliotti;F. Anselmetti;J. Beer;M. Çağatay;J. Channell;R. Kipfer;J. Lachner;T. Litt;N. Pickarski;M. Sturm
来自ICDP项目PALEOVAN的阿赫拉特海岭和北方盆地钻探点的货车湖沉积物岩心包含了大量关于过去环境过程的信息。沉积序列的日期使用气候地层对齐，纹层年代学，火山灰地层学，氩-氩单晶测年，放射性碳测年，磁性地层学，宇宙成因核素。在岩石地层格架的基础上，编制了不同的年龄限制，并建立了一个可靠而精确的60万年前的货车湖记录的年代学。总有机碳含量和沉积物颜色的代用记录，以及166米长的事件校正的阿赫拉特海岭记录的钙/钾比和树栖花粉百分比，模拟格陵兰同位素层型（NGRIP）。因此，代理记录系统地对齐NGRIP和合成格陵兰冰芯地层中反映的interstadial的起始。该年表是使用49个年龄控制点构建的，这些控制点是使用GICC 05时标与格陵兰冰芯地层进行视觉同步得出的，GICC 05时标是一个绝对定年的洞穴沉积物时标（例如，葫芦、三宝、临珠洞）和Epica Dome C时标。此外，该序列的最上部补充了四个年龄从全新世脉纹年代学和三个校准的放射性碳年龄。此外，9个氩-氩年龄和比较的相对古磁场强度记录与参考曲线PISO-1500证实了年龄模型的准确性。沉积物中~（10）Be含量的测定证实了Laschamp事件的存在，并证实了所提出的年龄模型。将阿赫拉特海岭记录的年代学转移到来自北方盆地的79米长的经事件校正的复合记录中，并通过对有机物残留物进行额外的放射性碳测年进行补充。北方盆地记录的基底年龄估计为1.90万年。总有机碳含量的时间序列的变化，Ca/K比，和乔木花粉百分比说明，所提出的年表链接冰-海洋-陆地地层和古气候数据是适合重建和模拟的第四纪和更新世的气候演变在近东千年的时间尺度。此外，最近250 ka的年代学可以用来测试其他测年技术。
Lake Van sediment cores from the Ahlat Ridge and Northern Basin drill sites of the ICDP project PALEOVAN contain a wealth of information about past environmental processes. The sedimentary sequence was dated using climatostratigraphic alignment, varve chronology, tephrostratigraphy, argon–argon single-crystal dating, radiocarbon dating, magnetostratigraphy, and cosmogenic nuclides. Based on the lithostratigraphic framework, the different age constraints are compiled and a robust and precise chronology of the 600,000 year-old Lake Van record is constructed. Proxy records of total organic carbon content and sediment color, together with the calcium/potassium-ratios and arboreal pollen percentages of the 166-m-long event-corrected Ahlat Ridge record, mimic the Greenland isotope stratotype (NGRIP). Therefore, the proxy records are systematically aligned to the onsets of interstadials reflected in the NGRIP and synthesized Greenland ice-core stratigraphy. The chronology is constructed using 49 age control points derived from visual synchronization with the Greenland ice-core stratigraphy using the GICC05 timescale, an absolutely-dated speleothem timescale (e.g., Hulu, Sanbao, Linzhu cave) and the Epica Dome C timescale. In addition, the uppermost part of the sequence is complemented with four ages from Holocene varve chronology and three calibrated radiocarbon ages. Furthermore, nine argon–argon ages and a comparison of the relative paleointensity record of the magnetic field with reference curve PISO-1500 confirm the accuracy of the age model. Also the identification of the Laschamp event via measurements of10Be in the sediment confirms the presented age model. The chronology of the Ahlat Ridge record is transferred to the 79-m-long event-corrected composite record from the Northern Basin and supplemented by additional radiocarbon dating on organic marco-remains. The basal age of the Northern Basin record is estimated at ∼90 ka. The variations of the time series of total organic carbon content, the Ca/K ratio, and the arboreal pollen percentages illustrate that the presented chronology links ice-marine-terrestrial stratigraphies and that the paleoclimate data are suited for reconstructions and modeling of the Quaternary and Pleistocene climate evolution in the Near East at millennial timescales. Furthermore, the chronology of the last 250 ka can be used to test other dating techniques.