REE/Fe variations in hydrothermal sediments: Implications for the REE content of seawater
- Univ. of Michigan, Ann Arbor (USA)
Seafloor hydrothermal vent solutions exhibit rare earth element (REE) enrichments ranging between one to three orders of magnitude greater than average seawater. To assess the impact of these hydrothermal inputs on ocean chemistry, the authors have examined he behavior of REEs for hydrothermal sediments collected adjacent to two Pacific spreading ridge sites: the East Pacific Rise at 19{degree}S, and the Southern Juan de Fuca Ridge at 45{degree}N. In general, the REE/Fe ratios for both proximal and distal hydrothermal sediments are greater than vent solutions by a factor of 2 to 500, and these ratios increase with increasing distance away from the ridge axis. An evaluation of these results in the context of previous models of REE behavior indicates that, in fact, seawater experiences a net depletion in REEs as a result of hydrothermal activity. This is due primarily to the large scavenging capacity of iron oxyhydroxides which precipitate from these solutions. Such an interpretation explains why the REE content of seawater collected in the vicinity of hydrothermal vents is anomalously lower than normal seawater sampled from a comparable depth.
- OSTI ID:
- 5163744
- Journal Information:
- Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 53:3; ISSN GCACA; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
152002* -- Geothermal Data & Theory-- Properties of Minerals & Rocks
58 GEOSCIENCES
580000 -- Geosciences
ABUNDANCE
CHEMICAL COMPOSITION
CHEMISTRY
CONCENTRATION RATIO
ELEMENT ABUNDANCE
ELEMENTS
ENERGY SYSTEMS
GEOCHEMISTRY
GEOTHERMAL SYSTEMS
HYDROGEN COMPOUNDS
HYDROTHERMAL ALTERATION
HYDROTHERMAL SYNTHESIS
HYDROTHERMAL SYSTEMS
HYDROXIDES
IRON
IRON COMPOUNDS
IRON HYDROXIDES
METALS
OXYGEN COMPOUNDS
PACIFIC OCEAN
PRECIPITATION
RARE EARTHS
ROCK-FLUID INTERACTIONS
SEAS
SEAWATER
SEDIMENTS
SEPARATION PROCESSES
SURFACE WATERS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VARIATIONS
WATER