Electronic Thesis and Dissertation Repository


Master of Science




Osinski, Gordon R.



The Sudbury Igneous Complex (SIC) represents the remnant of a crystalline impact melt sheet of the Sudbury impact structure; and is historically and presently a strategic exploration target sustaining the region's prolific mining camp. In order to better understand the SIC, it is critical to investigate the chilled upper contact of the SIC, which has historically received little recognition. Through field observations, whole rock geochemistry, petrography, and electron microprobe analysis, this study concludes that the SIC upper contact is in fact extensive across the North Range of the SIC. Additionally, the geochemistry of the SIC units, offset dykes, and upper contact unit (UCU) of the SIC presented here lead to the conclusion that the UCU roof rocks represent a more accurate proxy than the offset dykes for the initial composition of the SIC. Finally, this study indicates that the UCU lithology is no longer considered an intrusive melt of the basal Onaping Formation breccias.