The physico-chemical processes that operate at depth in transcrustal magma systems have implications for both volcanism at the Earth’s surface and the formation of critical mineral deposits in the crust. In subduction zones, these processes are poorly constrained, particularly for mantle-derived melts that have experienced little fractionation. The investigation of ancient, exhumed intrusions allows chemical data to be placed in spatial and textural context, providing information on both the architecture and physico-chemical evolution of magmas as they crystallize and evolve. My PhD research is contributing to the developing framework for transcrustal magma systems in subduction zones by investigating the Late Triassic Tulameen Alaskan-type intrusion in the Quesnel terrane of south-central British Columbia through a combined field, petrographic, and geochemical approach.
Education
- PhD (Candidate) in Geological Sciences: University of British Columbia. Supervisors: Dr. James Scoates; 2021-present
- BSc in Geology: University of British Columbia
Awards
- EOAS Graduate Scholarship (2023)
- Egil H. Lorntzsen Scholarship (2023)
- UBC Four Year Fellowship (2022)
- NSERC CGS-M (2021)
- British Columbia Graduate Scholarship (2020)
- GAC-PDAC Logan Student Prize (2020)
- Trek Excellence Scholarship for Continuing Students (2019)
- Economic Geology Memorial Scholarship (2019)
- Aho-Davis Undergraduate Prize in Geological Sciences (2019)
- Aaron Craig Nicholls Memorial Award (2019)
- Shell Mapping Prize for Excellence in Geological Fieldwork (2019)
- Art Soregaroli Memorial Award (2018)
- Thomas and Marguerite Mackay Memorial Scholarship (2018)
- Mineralogical Society of America Undergraduate Prize (2018)
- Thomas and Marguerite Mackay Memorial Scholarship (2017)
Peer-reviewed Publications
Nixon, G.T., Manor, M.J., Scoates, J.S., Spence, D.W., Milidragovic, D., in review, Mineralogical constraints on magma storage conditions in ultramafic arc cumulates and the nature and role of cryptic fugitive melts: Tulameen Alaskan-type intrusion, Canadian Cordillera. Contributions to Mineralogy and Petrology.
Spence, D.W., Scoates, J.S., Milidragovic, D., Nott, J.A., Nixon, G.T., 2024. Olivine in ultramafic rocks from the Polaris Alaskan-type intrusion: a geochemical record of open-system crystallization, diffusional re-equilibration, mantle source, and redox conditions in primitive arc magmas. Lithos. https://doi.org/10.1016/j.lithos.2024.107578
Milidragovic, D., Nott, J.A., Spence, D.W., Schumann, D., Scoates, J.S., Nixon, G.T., Stern, R.A., 2023. Sulfate recycling at subduction zones indicated by sulfur isotope systematics of Mesozoic ultramafic island arc cumulates in the North American Cordillera. Earth and Planetary Science Letters 620. https://doi.org/10.1016/j.epsl.2023.118337
Milidragovic, D., Nixon, G.T., Scoates, J.S., Nott, J.A., Spence, D.W., 2021. Redox-controlled chalcophile element geochemistry of the Polaris Alaskan-type mafic-ultramafic complex, British Columbia, Canada. The Canadian Mineralogist 59, 1627–1660. https://doi.org/10.3749/canmin.2100006
Fieldwork Articles
Spence, D.W., Crawford, H., Scoates, J.S., Nott, J.A., Nixon, G.T., Milidragovic, D., 2022. Mapping ultramafic cumulates at the Tulameen ultramafic-mafic Alaskan-type intrusion, south-central British Columbia, aided by remotely piloted aircraft system photogrammetry. British Columbia Ministry of Energy, Mines and Low Carbon Innovation, British Columbia Geological Survey Paper 2022-01, 103-122. https://cmscontent.nrs.gov.bc.ca/geoscience/publicationcatalogue/Paper/BCGS_P2022-01-07_Spence.pdf
Conference Publications and Abstracts
Spence, D.W., Scoates, J.S., Goan, I.R., Nott, J.A., Nixon, G.T., Milidragovic, D., 2024. Dynamic magmatic processes recorded in the Tulameen ultramafic-mafic Alaskan-type intrusion from outcrop-scale structures and mineral-scale textures. Association of Mineral Exploration Roundup Conference, January 2024. (Poster).
Goan, I.R., Scoates, J.S., Milidragovic, D., Spence, D.W., Nott, J.A., Moerhuis, N., Nixon, G.T., 2024. A microanalytical study of magnetite within Alaskan-type ultramafic-mafic intrusions in British Columbia. Association of Mineral Exploration Roundup Conference, January 2024. (Poster).
Scoates, J.S., Hickey, K.A., Moerhuis, N., Spence, D.W., Steiner, A.P., Saylor, J.E., 2023. Geological mapping at field school in the virtual environment. American Geophysical Union (AGU) Fall Meeting, Chicago, Illinois, USA, December 2023. (Poster and Abstract).
Spence, D.W., Scoates, J.S., Goan, I., Nott, J.A., Nixon, G.T., Milidragovic, D., 2023. LiDAR-, magnetic susceptibility-, and pXRF-assisted mapping at the Tulameen ultramafic-mafic Alaskan-type intrusion. Association of Mineral Exploration Roundup Conference, January 2023. (Poster).
Goan, I., Scoates, J.S., Moerhuis, N., Spence, D.W., Nott, J.A., Webb, R., Milidragovic, D., Nixon, G.T., 2023. An overview of petrological and geochemical investigations of Fe-Ti oxides within Alaskan-type ultramafic-mafic intrusions in British Columbia. Association of Mineral Exploration Roundup Conference, January 2023. (Poster).
Webb, R., Moerhuis, N., Scoates, J.S., Spence, D.W., Nott, J.A., Goan, I., Milidragovic, D., Nixon, G.T., 2023. Chromite in the Polaris Alaskan-type ultramafic-mafic intrusion of British Columbia: preliminary petrochemical results. Association of Mineral Exploration Roundup Conference, January 2023. (Poster).
Milidragovic, D., Nott, J.A., Spence, D.W., Scoates, J.S., Stern, R.A., 2022. Sulphur isotope systematics of island arc cumulates: Alaskan-type Polaris intrusion, North American Cordillera. American Geophysical Union (AGU) Fall Meeting, Chicago, Illinois, USA, December 2022. (Presentation and Abstract). https://agu.confex.com/agu/fm22/meetingapp.cgi/Paper/1077011
Spence, D.W., Scoates, J.S., Nott, J.A., Milidragovic, D., Nixon, G.T., 2022. Olivine in primitive arc magmas from the Polaris Alaskan-type intrusion in the North American Cordillera. Goldschmidt Conference, Honolulu, Hawai‘i, USA, July 2022. (Poster and Abstract). https://doi.org/10.46427/gold2022.11305
Nott, J.A., Scoates, J.S., Milidragovic, D., Nixon, G.T. Spence, D.W., 2022. Primitive arc magma conduits from the zircon petrochronology perspective in the Polaris Alaskan-type intrusion, North American Cordillera. Goldschmidt Conference, Honolulu, Hawai‘i, USA, July 2022. (Poster and Abstract). https://doi.org/10.46427/gold2022.11788
Spence, D.W., Crawford, H., Scoates, J.S., Nott, J.A., Nixon, G.T., Milidragovic, D., 2022. Mapping ultramafic cumulates at the Tulameen ultramaficmafic Alaskan-type intrusion, south-central British Columbia. Association of Mineral Exploration Roundup Conference, January 2022. (Poster).
Nixon, G.T., Scoates, J.S., Milidragovic, D., Nott, J., Manor, M.J., Spence, D.W., Kjarsgaard, I.M., 2021. Cu-PGE vs Cr-PGE mineralization in Alaskan-type mafic-ultramafic intrusions. Association of Mineral Exploration Roundup Conference, January 2021. (Poster). https://cmscontent.nrs.gov.bc.ca/geoscience/PublicationCatalogue/GeoFile/BCGS_GF2021-07.pdf?bcgovtm=20210311_GCPE_Vizeum_COVID___Google_Search_BCGOV_EN_BC__Text_Vizeum_COVID___Google_Search_BCGOV_EN_BC__Text
Milidragovic, D., Nixon, G.T., Scoates, J.S., Nott, J., Spence, D.W., 2021. Petrological controls on PGE mineralization in Alaskan-type intrusions. Association of Mineral Exploration Roundup Conference, January 2021. (Poster).
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. (Poster).
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 52, No. 6, 2020. https://doi.org/10.1130/abs/2020AM-357971
Undergraduate Thesis
Spence, D.W., 2020. Olivine in the Polaris Alaskan-type Intrusion of North-central British Columbia: Implications for the Magmatic Evolution of Primitive Arc Magmas and for Convergent Margin Ni-Cu-PGE Ore-forming Systems. University of British Columbia. https://open.library.ubc.ca/cIRcle/collections/undergraduateresearch/52966/items/1.0391065