onr:"swepub:oai:DiVA.org:su-177777"
Search: onr:"swepub:oai:DiVA.org:su-177777" > Iron isotopes revea...
- 1 of 1
- Previous record
- Next record
- To hitlist
Iron isotopes reveal the sources of Fe-bearing particles and colloids in the Lena River basin
-
- Hirst, Catherine (author)
- Stockholms universitet,Institutionen för geologiska vetenskaper,Swedish Museum of Natural History, Sweden
- Andersson, Per S. (author)
- Kooijman, Ellen (author)
- show more...
- Schmitt, Melanie (author)
- Maximov, Trofim (author)
- Porcelli, Don (author)
- show less...
- (creator_code:org_t)
- Elsevier BV, 2020
- 2020
- English.
- In: Geochimica et Cosmochimica Acta. - : Elsevier BV. - 0016-7037 .- 1872-9533. ; 269, s. 678-692
- Journal article (peer-reviewed)
Abstract
Subject headings
Close
- Large Arctic rivers are important suppliers of iron to the Arctic Ocean. However, the sources of Fe-bearing particles in permafrost-dominated systems and the mechanisms driving this supply of Fe are poorly resolved. Here, Fe isotope ratios were used to determine the sources of Fe-bearing particles and colloids in the Lena River and tributaries. In samples collected after the spring floods, Fe-bearing particles (>0.22 mu m) carried similar to 70% of the Fe and have isotope ratios that are lower than, or similar to that of the continental crust. These particles are composed of a leachable Fe fraction of largely ferrihydrite, with isotope values of -1.40 parts per thousand to -0.12 parts per thousand, and a fraction of clays and Fe oxides with continental crust values. Co-existing Fe-bearing colloids (<0.22 mu m), composed mainly of ferrihydrite, have higher isotope values, of -0.22 parts per thousand to +1.83 parts per thousand. A model is proposed in which soil mineral weathering generates aqueous Fe with lower delta Fe-56 values. During transport, a small fraction of the dissolved Fe is precipitated as colloidal ferrihydrite with higher delta Fe-56 values. Most of the Fe is precipitated onto mineral grains in oxic riparian zones, with the delta Fe-56 values largely generated during weathering. Groundwater discharge and riparian erosion supply the colloids and coated particles to the rivers. The differences between delta Fe-56 values in leachates and detrital grains in Fe-bearing particles agree with values determined in mineral dissolution experiments and in Fe accumulation horizons in soils. The difference in delta Fe-56 values between leachates and colloids reflects isotope fractionation during incremental Fe(III)(aq) precipitation and Fe-OC complexation during transport towards the riparian zone. Overall, the Fe isotope values of riverine particles and colloids reflect processes that occur during mineral dissolution, transport, and secondary mineral formation in permafrost soils.
Subject headings
- NATURVETENSKAP -- Geovetenskap och miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences (hsv//eng)
Keyword
- Iron
- Isotopes
- Colloids
- Particles
- Permafrost
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
- Geochimica et Cosmochimica Acta (Search for host publication in LIBRIS)
To the university's database
- 1 of 1
- Previous record
- Next record
- To hitlist
Find more in SwePub
- By the author/editor
- Hirst, Catherine
- Andersson, Per S ...
- Kooijman, Ellen
- Schmitt, Melanie
- Kutscher, Liselo ...
- Maximov, Trofim
- show more...
- Mörth, Carl-Magn ...
- Porcelli, Don
- show less...
- About the subject
-
- NATURAL SCIENCES
- NATURAL SCIENCES
- and Earth and Relate ...
- Articles in the publication
- Geochimica et Co ...
- By the university
- Stockholm University
Search outside SwePub
- Extend your search to:
- Google Book Search
- Google Scholar
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
- Copyright © LIBRIS - National Library Systems
- LIBRIS.kb.se
