Diamonds in cratonic and orogenic settings : a study of Jericho and Wawa diamonds ...

• Main Author: De Stefano, Andrea
• Format: Text
• Language: English
• Published: University of British Columbia 2011
• Subjects: Nunavut
• Online Access: https://dx.doi.org/10.14288/1.0053094; https://doi.library.ubc.ca/10.14288/1.0053094

Diamonds can form in a number of different ways. Physical and chemical properties of diamonds classify them as formed below cratons (xenocrystal cratonic) or in a subducting slab followed by rapid exhumation (orogenic). I studied diamonds from a cratonic (Jericho kimberlite, Nunavut) and a synorogenic (calc-alkaline lamprophyres of Wawa, Ontario) setting to reconstruct the process of diamond formation. Diamonds from these two locations have been analysed for their morphology, nitrogen content and aggregation, cathodoluminescence, composition of mineral inclusions, and stable carbon isotopes. In addition, fluorescence and stable nitrogen isotopes were studied in Wawa diamonds. Mineral inclusions in Jericho diamonds were compared with diamondiferous and non-diamondiferous eclogitic Jericho xenoliths with respect to major and trace element compositions. The majority of Jericho diamonds belong to “eclogitic” (90% of the studied samples) and “websteritic” (7%) assemblages. The Jericho diamonds differ from ...