Andrew Steiner

PhD

ESB 4047
graduate

My research concerns the hydrological regime responsible for the formation of Carlin-type gold deposits. These large, high-grade deposits formed from an ancient hot fluid that dissolved the limestones that host the deposits in a reaction that deposits gold. Knowing where, when, and how these fluids moved is critical for assessing the geologic potential of an area for hosting a Carlin-type deposit. My research has implications beyond economic geology because fluid circulation in the upper crust is a significant process in seismology, geothermal energy systems, and the early evolution of buried oceanic sediments.

For my PhD, I'm developing new geochemical methods for tracing fluid flow, and relating the inferred fluid flow pathways to the geological setting of the deposit and the wider region. Consequently, my thesis is strongly centred around field work, structural geology, and geochemistry. My two main study areas are the Nadaleen trend in Yukon, and the Cortez Hills region in Nevada. By the end of my studies, I will collectively have undertaken over nine months of fieldwork at these two sites, which mainly involves field geological mapping and logging drillcore. The goal of this fieldwork is to establish the geometry and characteristics of rocks, faults, and folds in and around the deposits to provide a geological context for identified fluid flow pathways. I also use this field time to identify potential fluid flow pathways by logging the presence of alteration minerals, looking at the variations in the elemental concentrations of rocks using X-ray fluorescence, and by looking for carbonate veins that fluoresce under UV light. These UV-fluorescent veins formed during gold deposition and give an indication of which structures the fluids are exploiting as they flow through the rocks.

In the laboratory, I use a range of techniques to characterize my samples. These include making petrographic observations of the rocks under the microscope and using cathodoluminescence, assessing the elemental variation between geological features using LA-ICP-MS, and analyzing the structure of minerals using Raman Spectroscopy. I am also developing a method for analyzing the formation age of carbonate using uranium-lead LA-ICP-MS. Furthermore, I commonly use variations in stable carbon and oxygen isotopes to identify fluid flow pathways and to distinguish different types of carbonate veins. I am collaborating with other researchers to use clumped carbon and oxygen isotopes to analyze the temperature of carbonate veins (and consequently, the fluids that formed them) to identify hotter and colder parts of the fluid flow regime.

BSc (Hons) University of Glasgow, Scotland, 2013-2017

MSc University of British Columbia, 2017 - 2019 (project upgraded to PhD)

PhD University of British Columbia, 2019 - present

               Articles published in peer-reviewed journals and peer-reviewed conference proceedings

Steiner, A.P., and Hickey, K, 2020. The physicochemical characteristics of ore fluids in Carlin-type Au-deposits inferred from ore-stage carbonate veins: an example from the Nadaleen trend, Yukon. Proceedings of the GSN Symposium 2020 (accepted) (Ph.D.)

Steiner, A.P., and Hickey, K, 2019. Ore-stage calcite veins in the Carlin-type Au-deposits of the Nadaleen trend, Yukon: a new addition to the economic geologist’s tool-kit. Proceedings of the 15th biennial SGA meeting, Glasgow, Scotland, v. 1, p. 267-270. (Ph.D.)

Koehn, D., Steiner, A., and Aanyu, K., 2019. Modelling of extension and dyking- induced collapse faults and fissures in rifts. Journal of Structural Geology v. 118  (21–31), p. 21-31. (B.Sc.)

Steiner, A., Hickey, K., and Coulter, A.B., 2018. The structural framework for Carlin-type gold mineralization in the Nadaleen trend, Yukon. In: Yukon Exploration and Geology 2017, K.E. MacFarlane (ed.), Yukon Geological Survey, p. 139-149. (M.Sc.)

Coulter, A. B., Lane, J., and Steiner, A., 2018. Osiris cluster Carlin-type gold, east-central Yukon. In: Yukon Exploration and Geology 2017, K.E. MacFarlane, (ed.), Yukon Geological Survey, p. 65-74. (M.Sc.)

Selected non-peer reviewed presentations and posters

Steiner, A.P*., and Hickey, K, 2019. Ore-stage calcite veins in the Carlin-type Au-deposits of the Nadaleen trend, Yukon: a new addition to the economic geologist’s tool-kit. Oral presentation, SGA meeting, Glasgow, Scotland, 27-30th August 2019. (International; Ph.D.)

Steiner, A.*., and Hickey, K, 2019. Exploring for Carlin-type Au-deposits using ore-stage, Mn-rich veins: implications for the timing, temperature, and scale of hydrothermal fluid flow. Poster presentation, PDAC, Toronto, Canada, 3-6th March 2019. (International; M.Sc.)

Hickey, K*, and Steiner, A., and 2019, Hydrological setting and geological controls on hydrothermal fluid flow in Carlin-type Au-deposits, Oral presentation, PACRIM, Auckland, New Zealand, 3-5th April 2019. (National; M.Sc.)

Steiner, A*., and Hickey, K., 2019, The structural evolution of the Nadaleen trend, Yukon: implications for Carlin-type Au-mineralization and Selwyn basin tectonics. Oral presentation, Cordilleran Tectonics Workshop, Vancouver, Canada, 22-24th February 2019. (National; M.Sc.)

Steiner, A*., and Hickey, K., 2019, Vertically-focused, fracture-controlled fluid flow into the Osiris-Sunrise Carlin-type Au-deposit, Yukon.. Poster presentation, AME Roundup 2019, Vancouver, Canada, 20-23rd January 2019. (International; M.Sc.)

Steiner, A*., and Hickey, K., 2019, Using Mn to explore for Carlin-type Au-deposits: insights from ore-stage calcite veins. Poster presentation, AME Roundup 2019, Vancouver, Canada, 20-23rd January 2019. (International; M.Sc.)

Steiner, A*., and Hickey, K, 2018, The role of fractures as a control on auriferous fluid flow in the Carlin-type Au-deposits of the Nadaleen trend, Yukon. Poster presentation, Geoscience Forum Yukon, Whitehorse, Canada, 17-20th November 2018. (Provincial; M.Sc.)

Steiner, A*., 2018, Controls on auriferous fluid flow at the Osiris-Sunrise Carlin-type Au-deposit, Yukon. Oral presentation, Carlin-type deposits in Yukon and Nevada short course, Geoscience Forum Yukon, Whitehorse, Canada, 17th November 2018. (Provincial; M.Sc.)

Steiner, A*., and Hickey, K., 2018, The role of fractures as a control on auriferous fluid flow in the Carlin-type Au-deposits of the Nadaleen trend, Yukon. Poster presentation, Geoscience Forum Yukon, Whitehorse, Canada, 17-20th November 2018. (Provincial; M.Sc.)

Steiner, A*., and Hickey, K., 2018, Do veins preserve fluid pathways in the Carlin-type Au deposits of the Nadaleen Trend, Yukon? Chemical, isotopic and petrographic insights. Poster presentation, Research for Future Generations, Vancouver, Canada, 16-21st June 2018. (International; M.Sc.)

Steiner, A*., and Hickey, K., 2018, Structural framework for Carlin-type gold mineralization: Nadaleen trend, Yukon. Poster presentation. AME Roundup 2018, Vancouver, Canada, 22-25th January 2018. (International; M.Sc.).

Steiner, A*., and Hickey, K., 2018, Structural framework for Carlin-type gold mineralization: Nadaleen trend, Yukon. Poster presentation. Yukon Geoscience Forum 2017, Whitehorse, Canada, 18-21st November 2017. (Provincial, M.Sc.).