My research at UBC focuses on the petrochronology and geochemistry of the Polaris ultramafic-mafic Alaskan-type intrusion in north-central British Columbia as a basis for resolving the role and evolution of primitive, hydrous and magnesium-rich, arc magmas in a convergent margin setting.
Alaskan-type intrusions belong to a class of convergent margin ultramafic-mafic intrusions that are gaining global importance as potential hosts to Ni-Cu-PGE mineralization. These intrusions typically exhibit a zonal distribution of rock types ranging from dunite in the core to clinopyroxenite, hornblendite, or gabbro at the margin and are characterized by a distinct lack of orthopyroxene. The Polaris intrusion is one of the best exposed Alaskan-type intrusions in the Canadian Cordillera, and provides a unique opportunity to observe the crystalline products of a mid-crustal magmatic system. It is an elongate sill-like body, 14 km long by 3 km across, that exhibits an asymmetric distribution of rock types with dunite in the east and gabbro-diorite to hornblende clinopyroxenite in the west.
Detailed mapping (1:15,000 scale), including preparation of a new geological map and intersecting cross sections, integrated with the results of a recent aeromagnetic survey have allowed for establishment of contact relationships and the 3D architecture of the Polaris intrusion. The results highlight the relative sequence of intrusions and document chaotic intrusive relationships (e.g., disrupted chromitites, irregular and gradational contacts, mixed assemblages) that provide strong evidence for significant internal remobilization during successive magma injections into a crystal-rich magma reservoir.
Ongoing research includes U-Pb geochronology and trace element characterization of zircon to constrain petrological processes and to develop an emplacement framework for the Polaris intrusion. With a solid geochronological framework, geochemical and isotopic analysis (Pb-Sr-Nd-Hf) of minerals and whole rocks will provide an opportunity to evaluate variations in source components, parent magma(s), and differentiation processes with respect to time. As the Early Jurassic Polaris intrusion coincides with the breakup of the Pangea supercontinent and the concurrent initiation of terrain accretion in the Cordillera, this research will have implications for our understanding of Cordilleran tectonics in the Early Jurassic and the evolution of subduction zone magmatism in this region.
- PhD (student) in Geological Sciences: University of British Columbia. Supervisors: Dr. James Scoates; 2020-present
- MSc in Geological Sciences: University of British Columbia. Supervisors: Dr. James Scoates; 2019-2020 (Upgraded to PhD)
- B.Sc. Geology, Environmental Science Dalhousie University; 2010 - 2015
- B.Sc. Earth Science, Environmental Science (Visiting), University of Victoria; Sept 2013 – Apr 2014
- Culinary Management/Chef Apprentice Basic & Advanced, Confederation College; 2003 - 2005
- NSERC CGS-M (2019)
- British Columbia Graduate Scholarship (2020)
- Dalhousie University Faculty of Science Dean’s list (2010-2014)
- Dalhousie University Earth Science Department Undergrad Scholarship (2012)
Confederation College First Class Standing (2003-2005)
Nott, J.A., Milidragovic, D., Nixon, G.T., Scoates, J.S., 2020a. Geology of the Polaris Alaskan-type ultramafic-mafic intrusion, north-central British Columbia. British Columbia Ministry of Energy, Mines and Petroleum Resources, British Columbia Geological Survey Open File 2020-04, 1:15,000 scale, 2 sheets. https://www2.gov.bc.ca/gov/content/industry/mineral-exploration-mining/british-columbia-geological-survey/publications/openfiles
Nott, J., Milidragovic, D., Nixon, G.T., and Scoates, J.S., 2020b. New geological investigations of the Early Jurassic Polaris ultramafic-mafic Alaskan-type intrusion, north-central British Columbia. In: Geological Fieldwork 2019, British Columbia Ministry of Energy, Mines and Petroleum Resources, British Columbia Geological Survey Paper 2020-01, 59-76. https://www2.gov.bc.ca/gov/content/industry/mineral-exploration-mining/british-columbia-geological-survey/publications/papers
Nixon, G.T., Scoates, J.S., Milidragovic, D., Nott, J., Moerhuis, N., Ver Hoeve, T.J., Manor, M.J., and Kjarsgaard, I.M., 2020. Convergent margin Ni-Cu-PGE-Cr ore systems: U-Pb petrochronology and environments of Cu-PGE versus Cr-PGE mineralization in Alaskan-type intrusions; in Targeted Geoscience Initiative 5: Advances in the understanding of Canadian Ni-Cu-PGE and Cr ore systems (ed.) W. Bleeker and M.G. Houlé; Geological Survey of Canada, Open File 8722, 197– 218. https://doi.org/10.4095/326702
Milidragovic, D., Nixon, G., Scoates. J.S., Nott, J.A., Spence, D.W., (in Prep). Chalcophile element geochemistry of the Polaris Alaskan-type mafic-ultramafic complex, north-central British Columbia. Canadian Mineralogist. (submitted Dec. 2020)
Conference presentations and abstracts: (* Presenting author)
Nott, J.A.*, 2020. A Canadian Cordilleran perspective of subduction zone magma reservoir architecture and origin of primitive arc magmatism. Canadian Tectonics Group workshop 2020, November 20-21, 2020. (Presentation with abstract)
Nott, J.A.*, Milidragovic, D., Nixon, G.T., Scoates, J.S. 2020. New geological investigations of the Early Jurassic Polaris ultramafic-mafic Alaskan-type intrusion, north-central British Columbia. Association for Mineral Exploration Roundup Conference, January 2020. (Abstract and poster presentation)
Spence, D.*, Scoates, J.S., Milidragovic, D., Nott, J.A., 2020. Olivine in the Polaris Alaskan-type intrusion of north-central British Columbia: Petrographic variation and preliminary geochemistry. Association of Mineral Exploration Roundup Conference, January 2020. (Abstract and poster presentation)
Milidragovic, D.*, Nixon, G.T., Scoates, J.S., Nott, J., and Spence, D.W. 2020. Redox controls on Cu-PGE-Au mineralization in the Polaris Alaskan-type intrusion, north-central British Columbia. Geological Society of America Abstracts with Programs. Vol 52, No. 6, 2020. doi: 10.1130/abs/2020AM-357971, Oct 2020.