Fe isotopic composition in continental iron cycle (Table 1), supplement to: Fantle, Matthew S; DePaolo, Donald J (2004): Iron isotopic fractionation during continental weathering. Earth and Planetary Science Letters, 228(3-4), 547-562

DOI

The effect of continental weathering on the iron isotope compositions of natural materials is investigated. Unweathered igneous rocks, pelagic clay, and dust fall within the range delta56Fe=0 +/- 0.3 per mil. Rivers with large suspended loads also have delta56Fe values near zero. Dilute streams have delta56Fe values that trend towards lower delta56Fe (~-1) suggesting that dissolved riverine iron is isotopically light relative to igneous rocks. Bulk soil and soil leaches display systematically different delta56Fe profiles, indicating that isotopically distinct Fe pools are generated during pedogenesis. Nannofossil ooze, which contains Fe scavenged from the ocean water column, has delta56Fe c. 0, but is consistent with seawater dissolved Fe having negative delta56Fe. It is inferred that continental weathering under modern oxidizing Earth surface conditions preferentially releases dissolved Fe with negative delta56Fe, which is transported in rivers to the ocean. A preliminary analysis of the marine Fe budget suggests that riverine Fe has a substantial role in determining the delta56Fe of both the modern and ancient oceans, but other inputs, particularly that from diagenesis of marine sediments, may also be important. Since the chemical pathways of Fe processing during weathering are dependent on oxidation state and biological activity, Fe isotopes may prove useful for detecting changes in these parameters in the geologic past.

Identifier
DOI https://doi.org/10.1594/PANGAEA.714650
Related Identifier https://doi.org/10.1016/j.epsl.2004.10.013
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.714650
Provenance
Creator Fantle, Matthew S; DePaolo, Donald J
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2004
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset
Format text/tab-separated-values
Size 20 data points
Discipline Earth System Research
Spatial Coverage (-157.832W, -31.167S, 163.358E, 30.332N); South Pacific/Tasman Sea/CONT RISE; Central North Pacific