Fe isotopic composition in continental iron cycle (Table 1)
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| Autores principales: | , |
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| Formato: | Dataset Open Access |
| Lenguaje: | en |
| Publicado: |
PANGAEA
2004
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| _version_ | 1867171755855970304 |
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| author | Fantle, Matthew S DePaolo, Donald J |
| author_facet | Fantle, Matthew S DePaolo, Donald J |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | 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. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_714650 |
| institution | PANGAEA |
| language | en |
| publishDate | 2004 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Fe isotopic composition in continental iron cycle (Table 1) Fantle, Matthew S DePaolo, Donald J 90-590B; AGE; Central North Pacific; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Leg90; LL44-GPC-3; Number; Ocean Drilling Program; ODP; PC; Piston corer; Sample code/label; South Pacific/Tasman Sea/CONT RISE; Thermal Ionization Mass Spectrometry (TIMS); δ56Fe; δ56Fe, standard deviation 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. |
| title | Fe isotopic composition in continental iron cycle (Table 1) |
| topic | 90-590B; AGE; Central North Pacific; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Event label; Glomar Challenger; Leg90; LL44-GPC-3; Number; Ocean Drilling Program; ODP; PC; Piston corer; Sample code/label; South Pacific/Tasman Sea/CONT RISE; Thermal Ionization Mass Spectrometry (TIMS); δ56Fe; δ56Fe, standard deviation |
| url | https://doi.org/10.1594/PANGAEA.714650 |