气候变化领域集成服务门户(CCPortal): Magnetic Properties of Sedimentary Smythite (Fe9S11)

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DOI	10.1029/2019JB018812
	Magnetic Properties of Sedimentary Smythite (Fe9S11)
	Horng C.-S.; Roberts A.P.; Chen Y.-H.; Shea K.-S.; Chen K.-H.; Lin C.-H.; Zhao X.; Chang C.-K.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	Smythite (Fe9S11) is an occasionally reported magnetic iron sulfide mineral that occurs in varied geological settings and co-occurs commonly with other magnetic iron sulfide minerals. Determining the magnetic properties of smythite is important for understanding its geological distribution and paleomagnetic and environmental magnetic significance. We report sedimentary smythite occurrences from three locations in Taiwan (one terrestrial and two marine), which suggest that smythite forms in methanic diagenetic environments into which sulfide has been reintroduced. We report the magnetic properties of our purest smythite sample, which also contains greigite, and compare them with those of other magnetic iron sulfide minerals. The magnetization of smythite is controlled by multiaxial anisotropy, with magnetic easy axes that lie within the crystallographic basal plane. Smythite is magnetically stable with no low-temperature magnetic transition. Hysteresis and coercivity properties of stable single domain smythite are similar to those of greigite at and below room temperature. The magnetic properties of smythite at elevated temperatures are dominated by thermal alteration, which precludes Curie temperature determination. In contrast to greigite and like pyrrhotite polytypes, smythite crystals occur as hexagonal plates. This morphological contrast facilitates discrimination of smythite from greigite in electron microscope observations, but it does not assist discrimination from pyrrhotite. Similar magnetic and morphological properties between smythite and other magnetic iron sulfides means that diagnostic mineralogical analyses (e.g., X-ray diffraction) are needed to identify these minerals. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	greigite; iron sulfides; magnetic properties; pyrrhotite; smythite
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187814
作者单位	Institute of Earth Sciences, Taipei, Taiwan; Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia; Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan; Central Geological Survey, Ministry of Economic Affairs, New Taipei, Taiwan; National Synchrotron Radiation Research Center, Hsinchu, Taiwan
推荐引用方式 GB/T 7714	Horng C.-S.,Roberts A.P.,Chen Y.-H.,et al. Magnetic Properties of Sedimentary Smythite (Fe9S11)[J],2020,125(6).
APA	Horng C.-S..,Roberts A.P..,Chen Y.-H..,Shea K.-S..,Chen K.-H..,...&Chang C.-K..(2020).Magnetic Properties of Sedimentary Smythite (Fe9S11).Journal of Geophysical Research: Solid Earth,125(6).
MLA	Horng C.-S.,et al."Magnetic Properties of Sedimentary Smythite (Fe9S11)".Journal of Geophysical Research: Solid Earth 125.6(2020).