Fundamental Magnetic Constants and Palaeomagnetic Recording Fidelity of Greigite (Fe3S4)

硅镁石 (Fe3S4) 的基本磁常数和古磁记录保真度

• 批准号: NE/G003319/1
• 负责人: Wyn Williams
• 金额: $ 2.88万
• 依托单位: University of Edinburgh
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FG003319%2F1
• 关键词: Fundamental; Magnetic; Constants; Palaeomagnetic; Recording

Greigite (Fe3S4) is a strongly magnetic mineral that is being increasingly recognised in the geological record. It is widely associated with anomalous magnetizations that complicate analysis of Earth's magnetic field behaviour and environmental change in sedimentary sequences. In particular, the Arctic is a frontier region where active international efforts are being made to understand past variations in climate. The presence of greigite in Arctic sediments makes it difficult to determine if palaeomagnetic observations result from unique magnetic field variations at high latitudes or from anomalous field recording associated with strongly magnetically interacting clusters of greigite grains. Despite the increasing recognition of the importance of greigite in the geological record, and in contrast with other important terrestrial magnetic minerals, key fundamental magnetic parameters for greigite remain unknown. This makes it impossible to model micro-scale magnetic characteristics to test whether authigenic growth of greigite in clusters can explain the anomalous magnetizations commonly associated with greigite. Recent work in the PI's research group has enabled identification of 2 of the 3 key parameters required to undertake such modelling. We request funds to determine the remaining key parameter and to undertake modelling that will provide the basis for assessing the palaeomagnetic recording fidelity of greigite. This work will benefit the international palaeomagnetic community who seek to understand high latitude geomagnetic field behaviour and the palaeoclimate community who widely use palaeomagnetic records to construct chronologies of climate change. Greigite growth is also associated with gas hydrate formation. The proposed work could therefore also provide parameters that would enable greigite to be used as a tracer for the former presence of methane hydrates in sedimentary sequences.

Greigite（Fe3S4）是一种强烈磁性矿物，在地质记录中越来越多地认识到。它与异常的磁化相关，使对地球磁场行为的分析和沉积序列的环境变化变得复杂。特别是，北极是一个边境地区，在这里进行了积极的国际努力，以了解过去的气候变化。北极沉积物中的绿岩石的存在使得难以确定古磁场是由高纬度的独特磁场变化引起的，还是由于与格林岩晶粒的磁性相互作用的簇相关的异常田间记录。尽管对地质记录中Greigite的重要性的认识越来越高，并且与其他重要的地面磁矿物质相反，Greigite的关键基本磁参数仍然未知。这使得不可能对微尺度磁性特征进行建模，以测试簇中Greigite的身份生长是否可以解释通常与Greigite相关的异常磁化。 PI研究小组的最新工作使得对进行此类建模所需的3个关键参数中的2个有鉴定。我们要求资金确定剩余的关键参数并进行建模，这将为评估Greigite的古磁记录保真度提供基础。这项工作将使试图了解高纬度地磁场行为和古气候社区的国际古磁社区受益，他们广泛使用古磁记录来构建气候变化的时间顺序。 Greigite的生长也与形成气体水合物有关。因此，提出的工作还可以提供参数，使Greigite可以用作沉积序列中甲烷水合物的示踪剂。

项目成果

ENIGMATIC X-RAY MAGNETIC CIRCULAR DICHROISM IN GREIGITE (Fe3S4)

硅灰石 (Fe3S4) 中神秘的 X 射线磁性圆二色性

• DOI: 10.3749/canmin.50.3.667
• 发表时间: 2012
• 期刊: The Canadian Mineralogist
• 作者: Chang L

Giant magnetofossils and hyperthermal events

• DOI: 10.1016/j.epsl.2012.07.031
• 发表时间: 2012-10-15
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Chang, Liao;Roberts, Andrew P.;Muxworthy, Adrian R.
• 通讯作者: Muxworthy, Adrian R.

Magnetotactic bacterial response to Antarctic dust supply during the Palaeocene-Eocene thermal maximum

• DOI: 10.1016/j.epsl.2012.04.003
• 发表时间: 2012-06-01
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Larrasoana, Juan C.;Roberts, Andrew P.;Zachos, James C.
• 通讯作者: Zachos, James C.

Critical single domain grain sizes in chains of interacting greigite particles: Implications for magnetosome crystals

• DOI: 10.1002/2013gc004973
• 发表时间: 2013-12
• 期刊: Geochemistry
• 影响因子: 3.7
• 作者: A. Muxworthy;W. Williams;A. Roberts;M. Winklhofer;Liao Chang;M. Pósfai

Magnetic vortex effects on first-order reversal curve (FORC) diagrams for greigite dispersions

• DOI: 10.1016/j.epsl.2018.08.027
• 发表时间: 2018-11
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: Miguel A. Valdez-Grijalva;A. Muxworthy;W. Williams;Pádraig Ó Conbhuí;L. Nagy;A. Roberts;D. Heslop