SIMS measurements of. delta. sup 34 S in sulfide minerals from adjacent vein and stratabound ores

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90010-3· OSTI ID:5551374

Shimizu, Nobumichi ^[1]

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1. Woods Hole Oceanographic Institution, MA (USA)

The effects of sample matrix and secondary ion energy on the instrument fractionation of sulfur isotopes have been studied for troilite, pyrite, and galena using the Caneca IMS-3f ion microprobe. An analytical procedure is described for the measurement of {delta}{sup 34}S on negatively charged sulfur ions from pyrite and galena with are producibility better than {plus minus} 1.5 {per thousand}. Sulfur isotope ratios were measured in pyrite and galena from adjacent stratabound manto orebodies and crosscutting veins in the Hualgayoc district of northern Peru. Isotopic compositions ({delta}{sup 34}S{sub CDT}) of sulfur in pyrite and galena from vein and manto deposits have a total range from {minus}20 to 10 per thousand. Sulfur in manto galenas has a wide range of isotopic compositions and is usually isotopic heavier than pyrite and galena suggests precipitation from separate fluids, consistent with textural evidence that galena is pargentically later than pyrite and often replaces it. The majority of pyrite and galena analyses from vein and manto ores are compatible with precipitation from ore fluids having {delta}{sup 34}S of aqueous sulfur of 0{plus minus} 5 per thousand. This result indicates that the associated igneous rocks may have been the source of sulfur in the ore minerals (as well as of lead). Low values of {delta}{sup 34}S in manto galena may be accounted for by incorporation of sulfur derived from diagenetic iron sulfides.

• OSTI ID: 5551374
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 55:2; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
DEVELOPING COUNTRIES
EVEN-EVEN NUCLEI
GALENA
GEOCHEMISTRY
GEOLOGIC HISTORY
ION MICROPROBE ANALYSIS
IRON COMPOUNDS
IRON SULFIDES
ISOTOPE RATIO
ISOTOPES
LATIN AMERICA
LEAD COMPOUNDS
LEAD SULFIDES
LIGHT NUCLEI
MICROANALYSIS
MINERALIZATION
MINERALS
NONDESTRUCTIVE ANALYSIS
NUCLEI
PERU
PETROGENESIS
PRECIPITATION
PYRITE
PYRRHOTITE
SEPARATION PROCESSES
SOUTH AMERICA
STABLE ISOTOPES
SULFIDE MINERALS
SULFIDES
SULFUR 34
SULFUR COMPOUNDS
SULFUR ISOTOPES
TRANSITION ELEMENT COMPOUNDS
TROILITE