Toward establishing precise 40Ar/39Ar chronologies for Late Pleistocene palaeoclimate archives: an example from the Lake Suigetsu (Japan) sedimentary record
Toward establishing precise 40Ar/39Ar chronologies for Late Pleistocene palaeoclimate archives: an example from the Lake Suigetsu (Japan) sedimentary record
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DOI：
10.1016/j.quascirev.2011.06.020
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发表时间：
2011-10
影响因子：
4
通讯作者：
V. Smith;D. Mark;R. Staff;S. Blockley;C. Ramsey;C. Bryant;T. Nakagawa;Kim Kyu Han;A. Weh;K. Takemura;T. Danhara
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文献类型：
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作者：
V. Smith;D. Mark;R. Staff;S. Blockley;C. Ramsey;C. Bryant;T. Nakagawa;Kim Kyu Han;A. Weh;K. Takemura;T. Danhara
水月岩柱（SG 06）是中纬度地区最重要的古气候档案之一，记录了近150 kyrs以来的连续沉积。许多可见和不可见的火山灰层形成了SG 06内独特的年龄标志。这些火山灰层太细，结晶贫乏，不能用40 Ar/39 Ar技术直接测定年代，因此火山灰与近源火山沉积物的玻璃碎片成分相关。获得了SG 06 -1288（U-Oki）近端火山灰（郁陵岛U4）的高精度40 Ar/39 Ar透长石年龄为10.0 ± 0.3ka（1σ，n = 34，MSWD = 0.71，p = 0.89），在较年轻的样品中，40 Ar/39 Ar的精度为±3%，而在较老的样品中，40 Ar/39 Ar的精度可能有所提高。这种火山灰层的40 Ar/39 Ar年龄可以提供宝贵的联系点内的水月湖SG 06序列，提供独立验证的核心的纹层年表，允许校准宇宙成因核素生产，并提供一个精确的年代学超出纹层限制。
The varved Suigetsu (SG06) sediment core is potentially one of the most important and well-constrained mid-latitude palaeoclimate archives, recording continuous deposition during the last ∼150 kyrs. Numerous visible and non-visible volcanic ash layers form unique age markers within SG06. These ash layers are too fine and crystal-poor to be directly dated using the40Ar/39Ar technique so the tephra were correlated to proximal volcanic deposits using their glass shard compositions. A high-precision40Ar/39Ar sanidine age of 10.0 ± 0.3 ka (1σ, n = 34, MSWD = 0.71, p = 0.89) was obtained for the SG06-1288 (U-Oki) proximal tephra (Ulleungdo U4).40Ar/39Ar yields a precision of ±3% near the younger limit of the method, with improved precision possible for older SG06 samples. Such40Ar/39Ar ages for tephra layers can provide invaluable tie-points within the Lake Suigetsu SG06 sequence, giving independent verification of the core’s varve chronology, allowing for the calibration of cosmogenic nuclide production, and providing a precise chronology beyond the varve limit.