Advected glacial seawater preserved in the subsurface of the Maldives carbonate edifice
Advected glacial seawater preserved in the subsurface of the Maldives carbonate edifice
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马尔代夫碳酸盐大厦地下保存的平流冰川海水
DOI：
10.1016/j.gca.2019.04.030
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发表时间：
2019
影响因子：
5
通讯作者：
Swart, Peter K.
中科院分区：
文献类型：
--
作者：
Blättler, Clara L.;Higgins, John A.;Swart, Peter K.
对马尔代夫内海沉积物岩心孔隙流体的保守地球化学示踪剂和反应地球化学示踪剂进行分析，揭示了广泛的间隙水团，其起源是通过马尔代夫碳酸盐构造横向平流的冰川中间水。这些岩心是在国际海洋发现计划的第359次考察中回收的，它们穿透了晚渐新世到最近的沉积物，包括碳酸盐台地、斜坡、远洋和漂流相。船上和岸上孔隙流体综合分析显示，氯离子浓度、δ 18o和δ D值分别为25 mM、1.2‰和9‰，呈线性共变变化。孔隙流体锶浓度与钙同位素比值呈强反相关关系。地球化学性质随深度的多次反转表明存在几个不同的间隙水团。这些变化被解释为代表了年轻（更新世和全新世）的水通过更古老的沉积地层平流的不同年龄和反应历史。特别是，氯离子浓度和水同位素比值的升高表明末次盛冰期的海水被保存在地下，在中至晚中新世沉积物中占据了超过400米的沉积物柱。这些孔隙流体约束了具有较高盐度和δ 18o、δ D值的中深度冰川水团的性质。该系统代表了一个独特的档案，提供了迄今为止最直接的冰川海水观测结果，也证明了碳酸盐台地系统中水岩相互作用的长期潜力。
Abstract Analysis of both conservative and reactive geochemical tracers in pore fluids extracted from sediment cores from the Maldives Inner Sea reveal extensive interstitial water masses whose origins lie in glacial intermediate water advected laterally through the Maldives carbonate edifice. These drillcores, recovered during Expedition 359 of the International Ocean Discovery Program, penetrate late Oligocene to Recent sediments including carbonate platform, slope, pelagic, and drift facies. Combined shipboard and shore-based analyses of the pore fluids show linearly co-varying changes in the concentration of chloride and δ 18 O and δ D values of 25 mM, 1.2‰, and 9‰, respectively. Additionally, pore fluid strontium concentrations and calcium isotope ratios are strongly anti-correlated with each other. Multiple reversals in these geochemical properties with depth indicate the existence of several distinct interstitial water masses. These variations are interpreted as representing the different ages and reactive histories of young (Pleistocene and Holocene) waters advecting through the much older sedimentary formations. In particular, the elevated chloride concentrations and water isotope ratios suggest that seawater from the Last Glacial Maximum is preserved in the subsurface, where it occupies over 400 m of the sediment column within Mid-to Late Miocene sediments. These pore fluids constrain the properties of an intermediate depth glacial water mass that had higher salinity and δ 18 O and δ D values than the average glacial ocean. This system represents a unique archive yielding the most direct observations of glacial seawater to date, as well as a demonstration of the long-lasting potential for water-rock interaction in carbonate platform systems.
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埃尼韦塔克环礁地下白云石起源的岩石学和地球化学限制：正常海水白云石化的一个例子
DOI：
--
发表时间：
1984
期刊：
影响因子：
--
作者：
A. Saller
通讯作者：
A. Saller
DOI：
10.1098/rstb.1977.0104
发表时间：
1977
期刊：
Philosophical Transactions of the Royal Society B
影响因子：
--
作者：
N. Shackleton
通讯作者：
N. Shackleton
影响因子：
3.9
作者：
Betzler, C.;Eberli, G. P.;Yao, Z.
通讯作者：
Yao, Z.
孔隙流体δ18O和[Cl−]的信息含量
影响因子：
3.5
作者：
Madeline D. Miller;M. Simons;J. Adkins;S. Minson
通讯作者：
S. Minson
从深海沉积物孔隙流体剖面重建末次冰期最大底层水盐度
DOI：
--
发表时间：
2003
期刊：
影响因子：
--
作者：
J. Adkins;D. Schrag
通讯作者：
D. Schrag