Oxygen-isotope composition and temperature of fluids involved in deposition of Proterozoic sedex deposits, Sudbury Basin, Ontario

1 October 1990

journal article
Published by Canadian Science Publishing in Canadian Journal of Earth Sciences

Vol. 27 (10) , 1299-1303
https://doi.org/10.1139/e90-139

Abstract

Sedex Cu–Pb–Zn deposits in the Sudbury Basin were deposited on the sea floor from fluids in which δ¹⁸O = −1‰ and at temperatures around 170 °C. Distal Mn-bearing sediments were deposited in seawater in which δ¹⁸O ≈ −3‰ and at temperatures around 125 °C. The fluids at the vent site (δ¹⁸O ≈ −1‰) probably represent a mixture of normal seawater and isotopically positive hydrothermal fluid generated in the substrate by seawater–rock reactions. The heat source responsible for convection and venting onto the sea floor and into the water column was the underlying Sudbury Irruptive, which was emplaced immediately following deposition of the Onaping Formation, directly above which the sedex deposits lie.

Keywords

OXYGEN ISOTOPE

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