A new model for transformation of ferrihydrite to hematite in soils and sediments

Jiang, Zhaoxia1,2,3; Liu, Qingsong3,4; Roberts, Andrew P.5; Barron, Vidal6; Torrent, Jose6; Zhang, Qiang7

2018-11

10.1130/G45386.1

GEOLOGY   影响因子和分区

0091-7613

1943-2682

Ferrihydrite is among the most common precursors for iron-oxide formation in soils and sediments. Previous studies proposed a three-stage process for ferrihydrite transformation to hematite via an intermediate ferrimagnetic phase, which provides the basis for interpreting iron-oxide formation and its paleoenvironmental significance. From our new results, we identified two extra stages in this transformation, which fundamentally change the conventional model. The revised five-stage model is: (I) magnetically ordered (or core-shell structured) superparamagnetic (SP) ferrihydrite formation, (II) rapid hematite formation from SP ferrihydrite, (III) relative hematite stabilization, (IV) maghemite nanoparticle neoformation, and (V) completion of the transformation from maghemite to hematite. Unlike the previous model, in which pedogenic maghemite and hematite were formed mainly in stages I and II, we conclude that they are formed dominantly in stages IV and V, respectively. Thus, our work provides a new framework for interpreting pedogenic iron oxides and their paleoclimatic implications in natural environments.

SCI ; EI

英语

NI论文

通讯

Australian Research Council[DP110105419] ; Australian Research Council[DP120103952]

Geology

Geology

WOS:000449047800015

GEOLOGICAL SOC AMER, INC

20184506039356

Sediments

Minerals:482.2 ; Soil Mechanics and Foundations:483

GEOSCIENCES

Web of Science

1.Ocean Univ China, Minist Educ, Key Lab Submarine Geosci & Prospecting Tech, Qingdao 266100, Peoples R China
2.Ocean Univ China, Coll Marine Geosci, Qingdao 266100, Peoples R China
3.Qingdao Natl Oceanog Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266237, Peoples R China
4.Southern Univ Sci & Technol, Shenzhen 518055, Peoples R China
5.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 2601, Australia
6.Univ Cordoba, Dept Agron, Edificio C4,Campus Rabanales, E-14071 Cordoba, Spain
7.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China

Jiang, Zhaoxia,Liu, Qingsong,Roberts, Andrew P.,et al. A new model for transformation of ferrihydrite to hematite in soils and sediments[J]. GEOLOGY,2018,46(11):987-990.

Jiang, Zhaoxia,Liu, Qingsong,Roberts, Andrew P.,Barron, Vidal,Torrent, Jose,&Zhang, Qiang.(2018).A new model for transformation of ferrihydrite to hematite in soils and sediments.GEOLOGY,46(11),987-990.

Jiang, Zhaoxia,et al."A new model for transformation of ferrihydrite to hematite in soils and sediments".GEOLOGY 46.11(2018):987-990.