Low-Temperature Magnetic Properties of Marine Sediments-Quantifying Magnetofossils, Superparamagnetism, and Maghemitization: Eastern Mediterranean Examples
文献类型：期刊论文
| 作者 | Qian, Yao3; Heslop, David3; Roberts, Andrew P.3; Hu, Pengxiang3; Zhao, Xiang3; Liu, Yan2; Li, Jinhua2; Grant, Katharine M.3; Rohling, Eelco J.1,3 |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
 |
| 出版日期 | 2021-09-01 |
| 卷号 | 126期号:9页码:22 |
| ISSN号 | 2169-9313 |
| DOI | 10.1029/2021JB021793 |
| 英文摘要 | Periodic and marked redox changes in eastern Mediterranean marine sediments drive environmental and diagenetic changes to which magnetic minerals are sensitive. Magnetic property changes, therefore, provide useful indications of paleoceanographic conditions during and after periods of organic-rich sediment (sapropel) deposition. Magnetic properties of eastern Mediterranean sediments at room temperature have been studied for decades; however, few studies have considered low-temperature magnetic properties. Here, we investigate the low-temperature (10-300 K) magnetic properties of different eastern Mediterranean sediment types combined with room temperature (similar to 300 K) magnetic properties, transmission electron microscopy, and calibrated X-ray fluorescence elemental data to illustrate the valuable information that can be obtained from low-temperature magnetic analysis of sediments. Our low-temperature magnetic results suggest that magnetite magnetofossils and superparamagnetic (SP) particles occur widely in eastern Mediterranean sediments. SP particle contents are highest in diagenetically reduced intervals associated with sapropels. In contrast, magnetite magnetofossils are most abundant in oxidation fronts at the tops of sapropels, where strong redox gradients formed, but are also widespread throughout other sedimentary intervals that have not been subjected to extensive reductive diagenesis. Moreover, the surfaces of magnetite particles are maghemitized (i.e., partially oxidized) in oxidation fronts at the tops of sapropels, and in other oxic sediment intervals. Our results demonstrate the value of LT magnetic measurements for quantifying diverse sedimentary magnetic signals of interest in environmental magnetism when studying paleoceanographic and paleoenvironmental processes. Plain Language Summary Magnetic minerals are sensitive to environmental changes. Investigating their variations through sedimentary sequences can provide information about ancient environmental and climatic changes. Room temperature magnetic properties are widely measured in environmental magnetism, while low-temperature (LT) magnetic properties that are measured between room temperature and similar to 10 K are studied much less, even though they can provide useful information about the presence of particular magnetic minerals and their particle size distributions. We present extensive LT analyses of Mediterranean marine sediments, together with room temperature magnetic, transmission electron microscope, and calibrated X-ray fluorescence elemental analyses to discuss redox changes of magnetic minerals within organic-rich sediment intervals to quantify these diverse magnetic particle types. Our LT results suggest that the fossilized remains of magnetotactic bacteria and tiny superparamagnetic particles occur widely in eastern Mediterranean sediments, and that the surfaces of magnetite particles are widely oxidized and provide a measure of sedimentary oxidation variations. This work demonstrates that LT magnetic measurements can be used to quantify diverse sedimentary magnetic signals, and will be widely applicable in paleoenvironmental magnetic research. |
| WOS关键词 | ACTIVE OXIDATION FRONT ; GRAIN-SIZE DEPENDENCE ; DEEP-SEA SEDIMENTS ; AFRICAN MONSOON ; SINGLE-DOMAIN ; SATURATION REMANENCE ; PELAGIC SEDIMENTS ; VERWEY TRANSITION ; SAPROPEL-BEARING ; ISOTOPE DATA |
| 资助项目 | Australian Research Council[DP160100805] ; Australian Research Council[DP200100765] ; National Natural Science Foundation of China[41920104009] ; National Natural Science Foundation of China[41890843] ; China Scholarship Council |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| 出版者 | AMER GEOPHYSICAL UNION |
| WOS记录号 | WOS:000703087900030 |
| 资助机构 | Australian Research Council ; Australian Research Council ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Scholarship Council ; China Scholarship Council ; Australian Research Council ; Australian Research Council ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Scholarship Council ; China Scholarship Council ; Australian Research Council ; Australian Research Council ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Scholarship Council ; China Scholarship Council ; Australian Research Council ; Australian Research Council ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; China Scholarship Council ; China Scholarship Council |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/102753]  |
| 专题 | 地质与地球物理研究所_中国科学院地球与行星物理重点实验室 |
| 通讯作者 | Qian, Yao |
| 作者单位 | 1.Univ Southampton, Natl Oceanog Ctr, Ocean & Earth Sci, Southampton, Hants, England 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing, Peoples R China 3.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT, Australia |
| 推荐引用方式 GB/T 7714 | Qian, Yao,Heslop, David,Roberts, Andrew P.,et al. Low-Temperature Magnetic Properties of Marine Sediments-Quantifying Magnetofossils, Superparamagnetism, and Maghemitization: Eastern Mediterranean Examples[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021,126(9):22. |
| APA | Qian, Yao.,Heslop, David.,Roberts, Andrew P..,Hu, Pengxiang.,Zhao, Xiang.,...&Rohling, Eelco J..(2021).Low-Temperature Magnetic Properties of Marine Sediments-Quantifying Magnetofossils, Superparamagnetism, and Maghemitization: Eastern Mediterranean Examples.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,126(9),22. |
| MLA | Qian, Yao,et al."Low-Temperature Magnetic Properties of Marine Sediments-Quantifying Magnetofossils, Superparamagnetism, and Maghemitization: Eastern Mediterranean Examples".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 126.9(2021):22. |
入库方式： OAI收割
来源：地质与地球物理研究所
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