Sulfur isotopes in Finnish nickel-copper occurrences

• Main Authors: H. Papunen, M. Mäkelä
• Format: Article
• Language: English
• Published: Geological Society of Finland 1980-06-01
• Series: Bulletin of the Geological Society of Finland
• Online Access: http://www.geologinenseura.fi/bulletin/Volume52/sgs_bt_052_1_pages_055_066.pdf

The sulfur isotope composition of the Hitura, Kotalahti and Kylmäkoski Ni-Cu ores was analyzed. The results have been compared with earlier sulfur isotope analyses of the Vammala, Laukunkangas and Oravainen Ni-Cu occurrences. Altogether 183 analyses were performed. The magmatic origin of sulfides is supported by the isotope compositions that deviate only slightly from the meteoritic value. It is suggested that the initial sulfur isotope composition was homogeneous, δ34S values being ca. + 2.5 at Hitura, + 2.0 at Kotalahti, close to zero at Kylmäkoski and at Laukunkangas, ‒ 1 at Vammala and + 2.8 at Oravainen. The metamorphic redistribution of sulfides and the mixing of magmatic Ni-Cu sulfides with wall-rock iron sulfides cause local variations in δ34S values.