Impact of Aeolian Dry Deposition of Reactive Iron Minerals on Sulfur Cycling in Sediments of the Gulf of Aqaba.
Impact of Aeolian Dry Deposition of Reactive Iron Minerals on Sulfur Cycling in Sediments of the Gulf of Aqaba.
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DOI：
10.3389/fmicb.2017.01131
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发表时间：
2017
影响因子：
5.2
通讯作者：
Kamyshny A Jr
中科院分区：
文献类型：
--
作者：
Blonder B;Boyko V;Turchyn AV;Antler G;Sinichkin U;Knossow N;Klein R;Kamyshny A Jr
亚喀巴湾是一个贫营养海洋系统，具有富氧水体和贫有机碳沉积物（在不受人为影响的地点≤0.6%）。阿拉伯、西奈和撒哈拉沙漠的风尘沉积是沉积物的重要来源，特别是在海湾深水区，这些地区在季节性山洪期间受阿拉瓦沙漠沉积物输送的影响较小。沉积物中微生物硫酸盐的还原是根据黄铁矿的存在（尽管浓度相对较低）、硫化物氧化中间体的存在以及硫酸盐和固相硫化物的硫同位素组成推断的。撒哈拉尘埃的特点是含有大量铁矿物，如赤铁矿和针铁矿。我们证明，源自沙漠灰尘的风积干沉积而产生的活性铁（III）（氢）氧化物的高沉积含量，导致微生物硫酸盐还原过程中产生的硫化氢快速再氧化，并限制了黄铁矿形式还原硫的保存。我们的结论是，在这些地点，沉积硫循环可能被定义为神秘的。
The Gulf of Aqaba is an oligotrophic marine system with oxygen-rich water column and organic carbon-poor sediments (≤0.6% at sites that are not influenced by anthropogenic impact). Aeolian dust deposition from the Arabian, Sinai, and Sahara Deserts is an important source of sediment, especially at the deep-water sites of the Gulf, which are less affected by sediment transport from the Arava Desert during seasonal flash floods. Microbial sulfate reduction in sediments is inferred from the presence of pyrite (although at relatively low concentrations), the presence of sulfide oxidation intermediates, and by the sulfur isotopic composition of sulfate and solid-phase sulfides. Saharan dust is characterized by high amounts of iron minerals such as hematite and goethite. We demonstrated, that the resulting high sedimentary content of reactive iron(III) (hydr)oxides, originating from this aeolian dry deposition of desert dust, leads to fast re-oxidation of hydrogen sulfide produced during microbial sulfate reduction and limits preservation of reduced sulfur in the form of pyrite. We conclude that at these sites the sedimentary sulfur cycle may be defined as cryptic.