Cobalt and marine redox evolution
Cobalt and marine redox evolution
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钴和海洋氧化还原演化
DOI：
10.1016/j.epsl.2014.01.001
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发表时间：
2014
影响因子：
5.3
通讯作者：
Konhauser
中科院分区：
文献类型：
--
作者：
Swanner;Planavsky;Lalonde;Robbins;Bekker;Rouxel;Kappler;Mojzsis;Konhauser
钴(Co)是一种生物必需的微量元素，也是现代海洋某些区域的限制性营养物质。根据厌氧微生物相对于动植物对钴的较大利用，认为前寒武纪前寒武纪通风不良的海洋中钴的含量更丰富。然而，关于海水钴浓度历史的经验或理论约束很少。在此，我们对海洋沉积物(铁建造、自生黄铁矿和大块正辛质页岩)中的自生钴进行了调查，目的是追踪地球历史上海相钴储量的变化。我们进一步提供了现代海洋钴循环的概述，我们将其作为评估地球表面氧化还原状态的变化如何影响海洋钴浓度的平台。根据沉积钴含量和我们对海洋钴源和汇的认识，我们认为，在2.8~1.8Ga之间，大量的热液流经丰富的海底超镁铁质岩石，伴随着一个以缺氧为主、钴埋藏量低的海洋，形成了一个大型的海相钴藏。我们初步认为，在约1.8Ga之后，由于热液钴源的减弱和硫化物钴埋藏通量的扩大，海洋钴的浓度有所下降。新元古代深水通风引起的钴储集层的变化，如果发生了变化，则不能用当前的数据集来解析。相反，在海洋缺氧事件(OAE)期间沉积的显生宙正辛质页岩中的Co富集物表明，Co来自扩大的缺氧沉积物和增强的热液来源。一项新的海洋钴浓度记录提供了一个平台，我们可以从这个平台重新评估环境钴浓度在整个地球历史上对生物钴利用所起的作用。
Cobalt (Co) is a bio-essential trace element and limiting nutrient in some regions of the modern oceans. It has been proposed that Co was more abundant in poorly ventilated Precambrian oceans based on the greater utilization of Co by anaerobic microbes relative to plants and animals. However, there are few empirical or theoretical constraints on the history of seawater Co concentrations. Herein, we present a survey of authigenic Co in marine sediments (iron formations, authigenic pyrite and bulk euxinic shales) with the goal of tracking changes in the marine Co reservoir throughout Earth's history. We further provide an overview of the modern marine Co cycle, which we use as a platform to evaluate how changes in the redox state of Earth's surface were likely to have affected marine Co concentrations. Based on sedimentary Co contents and our understanding of marine Co sources and sinks, we propose that from ca. 2.8 to 1.8 Ga the large volume of hydrothermal fluids circulating through abundant submarine ultramafic rocks along with a predominantly anoxic ocean with a low capacity for Co burial resulted in a large dissolved marine Co reservoir. We tentatively propose that there was a decrease in marine Co concentrations after ca. 1.8 Ga resulting from waning hydrothermal Co sources and the expansion of sulfide Co burial flux. Changes in the Co reservoir due to deep-water ventilation in the Neoproterozoic, if they occurred, are not resolvable with the current dataset. Rather, Co enrichments in Phanerozoic euxinic shales deposited during ocean anoxic events (OAE) indicate Co mobilization from expanded anoxic sediments and enhanced hydrothermal sources. A new record of marine Co concentrations provides a platform from which we can reevaluate the role that environmental Co concentrations played in shaping biological Co utilization throughout Earth's history.
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影响因子：
10.6
作者：
Barbosa, Daniel;Dietenbeck, Thomas;Bernard, Olivier
通讯作者：
Bernard, Olivier
影响因子：
4.1
作者：
S. Weech;A. Scheuhammer;J. Elliott
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DOI：
--
发表时间：
2012
期刊：
Wetlands (Wilmington, N.C.)
影响因子：
--
作者：
T. Minello;L. Rozas;P. Caldwell;C. Liese
通讯作者：
C. Liese
影响因子：
2.5
作者：
L. Rozas;T. Minello;R. Zimmerman;P. Caldwell
通讯作者：
L. Rozas;T. Minello;R. Zimmerman;P. Caldwell
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影响因子：
4
作者：
S. N. Wiemeyer;T. Lamont;C. Bunck;C. R. Sindelar;F. J. Gramlich;J. Fraser;M. Byrd
通讯作者：
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