Archive · collection · 1988
Osmium concentration and isotopic composition of North Pacific deep-sea sediments
Listed in PANGAEA
Pelagic clay and Mn nodules from DOMES sites in the North Pacific and a varved glacial lake deposit from Connecticut were analysed for Os concentration and isotopic composition by isotope-dilution secondary ion mass spectrometry after treatment by NiS fusion or oxalic acid leaching.
Description
Bulk pelagic clay from DOMES site C has 187Os/186Os = 6.5 and Os = 0.14 ng/g. Oxalic acid leaches of this same sediment and of Mn nodules from DOMES sites A and C have more radiogenic 187Os/186Os ratios which average 8.3.
Bulk glacial Lake Hitchcock sediment has 187Os/186Os = 12.5 and Os = 0.06 ng/g. The total Os flux to North Pacific pelagic clay is 7 to 10 ng Os/cm**2/10**6 y. Lake Hitchcock sediment provides an integrated value for the local crustal 187Os/186Os ratio.
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The oxalic acid leaches are assumed to attack hydrogenous phases selectively. A simple model in which the only sources of Os to the ocean are continental crust with the isotopic composition of Lake Hitchcock (187Os/186Os = 12.5) and extraterrestrial particles with 187Os/186Os = 1.1 results in a cosmic flux of osmium to the sediment of 4.9 ng Os/cm**2/10**6 y of which 20% is hydrogenous. A model in which the sources of Os to the ocean are continental crust with an 187Os/186Os ratio of 30 (from the model of Palmer and Turekian, 1986), oceanic mantle or crust with 187Os/186Os = 1.04 and extraterrestrial particles with 187Os/186Os = 1.1 results in a cosmic flux of Os to the sediment of 5.7 ng Os/cm**2/10**6 y of which none is hydrogenous.
These extraterrestrial Os fluxes correspond to maximum C-1 chondrite accretion rates of between 4.9 × 104 and 5.6 × 104 tonnes/y.
Links
Where it is published
- DOI doi.org/10.1594/pangaea.880007 ↗
DOI / persistent id · from PANGAEA
Catalogue records · 1
- OAI-PMH record ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=oai_dc&identifier=o… ↗
metadata API · from PANGAEA
Topics
- From keywords
- Earth & Environmental Science
- Inferred from text
- Isotope geochemistry 81% · Mass spectrometry 75%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| PANGAEA | oai:pangaea.de:doi:10.1594/PANGAEA.880007 | 11 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · PANGAEA | connector:pangaea@1.0.0 | |
| concepts[field].anzsrc:field:370303 | enrichment · PANGAEA | taxonomy-embedding@1.1.0 | title+keywords+description (81%) |
| concepts[field].local:field:earth-environmental | mapping · PANGAEA | connector:pangaea@1.0.0 | |
| concepts[modality].local:modality:mass-spectrometry | enrichment · PANGAEA | keyword-concept-rules@1.0.0 | title+description (75%) |
| description | source · PANGAEA | connector:pangaea@1.0.0 | /metadata/dc/description |
| license | source · PANGAEA | connector:pangaea@1.0.0 | /metadata/dc/rights |
| publication_date | source · PANGAEA | connector:pangaea@1.0.0 | |
| spatial | source · PANGAEA | connector:pangaea@1.0.0 | |
| title | source · PANGAEA | connector:pangaea@1.0.0 | /metadata/dc/title |