Stable Cu, Fe, and Ni Isotopic Systematics of the Sudbury Offset Dikes and Associated Rocks

Author

Peter Christoffersen, The University of Western OntarioFollow

Degree

Master of Science

Program

Geology

Supervisor

Bouvier, Audrey

2nd Supervisor

Osinski, Gordon

Co-Supervisor

Abstract

The stable isotope ratio compositions of Fe, Ni, and Cu (δ⁵⁶Fe, δ⁶⁰Ni, and δ⁶⁵Cu) are reported for the first time in rocks from the Sudbury Igneous Complex (SIC). Massive sulfide ores, Quartz Diorite (QD), Inclusion bearing Quartz Diorite (IQD), and rocks from members of the Main Mass of the SIC were analyzed. The objective was to better understand the origin(s) and source(s) of the Offset Dikes and the associated sulfide mineralization. Based on stable isotope ratios and petrographic observations, two distinct types of sulfide mineralization hosted within the Offset Dikes are identified. Massive sulfide mineralization hosted within the Offset Dikes was identified to be different than the disseminated blebby sulfide mineralization found within the QD and IQD, based on coordinated isotopic and petrographic analyses. Comparisons of the stable isotope ratios of Fe, Ni, and Cu between rock samples from different Offset Dikes established a homogeneity in Fe, Ni, and Cu compositions. Including between the QD and IQD, and their disseminated sulfides. A correlation between δ⁶⁰Ni, and δ⁶⁵Cu values, with lighter compositions for the massive sulfides compared to the residual main mass, indicates an early magmatic origin for the massive sulfides compared to the disseminated sulfides contained in the Offset Dikes.

Recommended Citation

Christoffersen, Peter, "Stable Cu, Fe, and Ni Isotopic Systematics of the Sudbury Offset Dikes and Associated Rocks" (2017). Electronic Thesis and Dissertation Repository. 5179.
https://ir.lib.uwo.ca/etd/5179