Distribution and composition of hydrothermal plume particles from the ASHES vent field at Axial Volcano, Juan de Fuca Ridge. [Axial Seamount Hydrothermal Emission Study]
- NOAA, Seattle, WA (United States)
- NOAA, Newport, OR (United States)
In 1986 and 1987, buoyant and neutrally buoyant hydrothermal plume particles from the ASHES vent field within Axial Volcano were sampled to study their variations in composition with height above the seafloor. Individual mineral phases were identified using standard X ray diffraction procedures. Elemental composition and particle morphologies were determined by X ray fluorescence spectrometry and scanning electron microscopy/X ray energy spectrometry techniques. The vent particles were primarily composed of sphalerite, anhydrite, pyrite, pyrrhotite, chalcopyrite, barite, hydrous iron oxides, and amorphous silica. Grain size analyses of buoyant plume particles showed rapid particle growth in the first few centimeters above the vent orifice, followed by differential sedimentation of the larger sulfide and sulfate minerals out of the buoyant plume. The neutrally buoyant plume consisted of a lower plume, which was highly enriched in Fe, S, Zn, and Cu, and an upper plume, which was highly enriched in Fe and Mn. The upper plume was enriched in Fe and Mn oxyhydroxide particles, and the lower plume was enriched in suspended sulfide particles in addition to the Fe and Mn oxyhydroxide particles. The chemical data for the water column particles indicate that chemical scavenging and differential sedimentation processes are major factors controlling the composition of the dispersing hydrothermal particles. Short-term sediment trap experiments indicate that the fallout from the ASHES vent field is not as large as some of the other vent fields on the Juan de Fuca Ridge.
- OSTI ID:
- 5108416
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 95:B8; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
PACIFIC OCEAN
VOLCANOES
VOLCANIC ROCKS
GEOCHEMISTRY
ANHYDRITE
BARITE
CHALCOPYRITE
CHEMICAL COMPOSITION
COPPER
DISTRIBUTION
ENRICHMENT
GRAIN SIZE
IRON
IRON OXIDES
MANGANESE
MORPHOLOGY
PARTICULATES
PYRITE
PYRRHOTITE
SAMPLING
SCANNING ELECTRON MICROSCOPY
SEDIMENTATION
SILICA
SPHALERITE
SULFATES
SULFIDES
SULFUR
X-RAY DIFFRACTION
X-RAY FLUORESCENCE ANALYSIS
X-RAY SPECTROSCOPY
ZINC
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMISTRY
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
IGNEOUS ROCKS
IRON COMPOUNDS
IRON SULFIDES
METALS
MICROSCOPY
MICROSTRUCTURE
MINERALS
NONDESTRUCTIVE ANALYSIS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLES
ROCKS
SCATTERING
SEAS
SILICON COMPOUNDS
SILICON OXIDES
SIZE
SPECTROSCOPY
SULFATE MINERALS
SULFIDE MINERALS
SULFUR COMPOUNDS
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY EMISSION ANALYSIS
152001* - Geothermal Data & Theory- Properties of Aqueous Solutions
580000 - Geosciences