The use of the laser Raman microprobe for the determination of salinity in fluid inclusions

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(89)90022-7· OSTI ID:5022729

Mernagh, T P; Wilde, A R ^[1]

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1. Bureau of Mineral Resources, Canberra (Australia)

The O-H stretching region (2,800-3,800 cm{sup {minus}1}) in Raman spectra of aqueous solutions is sensitive to changes in the salt concentration. This permits determination of the salinity in the aqueous phase of fluid inclusions (at room temperature) by calculating skewing parameters from Raman microprobe spectra. The technique does not require detailed knowledge of the fluid composition and can be applied to most chloride solutions which commonly occur in fluid inclusions. Studies of synthetic fluid inclusions from the NaCl-H{sub 2}O system show that salinities up to halite saturation may be determined to within {plus minus}2 wt%. Well-characterized fluid inclusions from the unconformity-related uranium deposits of Nabarlek and Koongarra, Northern Territory, Australia, were studied with the laser Raman microprobe. The salinities determined from the Raman spectra are comparable to those obtained using standard microthermometric techniques. The Raman microprobe technique has the advantage of not requiring analogy to binary salt-water phase diagrams which cannot adequately model the complex brines in these inclusions. Variations in the concentration of salt hydrates, observed in Raman spectra of frozen inclusion, validated the salinities derived from the Raman skewing parameters obtained at room temperature. The Raman analyses confirm previous microthermometric evidence for trapping of discrete high and low salinity fluids.

• OSTI ID: 5022729
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 53:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
INCLUSIONS
CHEMICAL COMPOSITION
RAMAN SPECTROSCOPY
SALINITY
KOONGARRA DEPOSIT
NABARLEK DEPOSIT
AQUEOUS SOLUTIONS
BRINES
CONCENTRATION RATIO
GEOCHEMISTRY
NORTHERN TERRITORY
PHASE STUDIES
RAMAN SPECTRA
SODIUM CHLORIDES
ALKALI METAL COMPOUNDS
AUSTRALASIA
AUSTRALIA
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
DISPERSIONS
GEOLOGIC DEPOSITS
HALIDES
HALOGEN COMPOUNDS
LASER SPECTROSCOPY
MINERAL RESOURCES
MIXTURES
RESOURCES
SODIUM COMPOUNDS
SOLUTIONS
SPECTRA
SPECTROSCOPY
URANIUM DEPOSITS
580000* - Geosciences
050100 - Nuclear Fuels- Reserves
Exploration
& Mining