Sulfur isotope fractionation in sulfide mineralization

Journal Article · Sun May 01 04:00:00 EDT 1960 · Economic Geology

DOI:https://doi.org/10.2113/gsecongeo.55.3.510· OSTI ID:4163216

Gavelin, S.; Parwel, A.; Ryhage, R.

The isotopic compositions of sulfides and sulfates from various types of sulfide formations were determined. A description of the preparation of sulfurous minerals for mass-spectrometric analysis and of the massspectrometric procedure is given. The results agree in several respects with previous investigations. Various sulfides representing a continuous mineralization process display no significant divergencies if the early and the late minerals are compared. Nor does the material examined indicate any correlation between isotopic composition and zonal arrangement of minerals and metals around emanative centers, in cases where such zoning is evidenced by the regional geological features. A certain correlation between kind of wallrock and isotopic composition may be indicated. If considerable variations of isotopic compositions are found to exist in an ore district, the range of variation seems to be wider in the low-temperature than in the high-temperature sulfides. Supergene oxidation of sulfides to sulfate takes place without change in isotopic composition. A subsequent redeposition of supergene sulfides may involve a displacement of the isotope ratios towards lighter sulfur. Hypogene sulfide mineralization, where both sulfides and sulfates are formed, is apt to cause significant fractionation of the original isotopic composition of the participant sulfur. Local variations indicate that the process may develop differently over short distances. The local character of some isotope exchange reactions is evidenced for instance by considerable variation in the isotope ratios even in a single hand specimen. The range of such variations is generally found to be wider in lowtemperature than in high-temperature mineral assemblages. (auth)

• Research Organization: Stockholms Hogskola, Stockholm
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-016892
• OSTI ID: 4163216
• Journal Information: Economic Geology, Journal Name: Economic Geology Journal Issue: 3 Vol. 55; ISSN 0361-0128
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CONFIGURATION
DISTRIBUTION
GEOLOGY
GEOLOGY, MINERALOGY, AND METEOROLOGY
ISOTOPIC EXCHANGE
MASS SPECTROMETERS
METALS
MINERALS
OSCILLATIONS
OXIDATION
PREPARATION
ROCKS
SAMPLING
SULFATES
SULFIDES
SULFUR ISOTOPES