Western University Scholarship@Western Electronic Thesis and Dissertation Repository 10-3-2018 10:00 AM Near-Earth Asteroid Resources: Review and Analogue Study of Highly Siderophile Elements in Main-Group Pallasites Liam R. J. Innis The University of Western Ontario Supervisor Osinski, Gordon R. The University of Western Ontario Graduate Program in Geology A thesis submitted in partial fulfillment of the equirr ements for the degree in Master of Science © Liam R. J. Innis 2018 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geology Commons Recommended Citation Innis, Liam R. J., "Near-Earth Asteroid Resources: Review and Analogue Study of Highly Siderophile Elements in Main-Group Pallasites" (2018). Electronic Thesis and Dissertation Repository. 5852. https://ir.lib.uwo.ca/etd/5852 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. Abstract The potential for Near-Earth asteroids (NEAs) as targets for space resource utilization has been explored. Water and platinum group elements (PGE)s have been identified as resources with potential profitability in existing markets. A parameterization accounting for asteroid size, resource concentration, and accessibility yields just seven and three potentially viable NEA targets for water and PGEs respectively. Improved NEA discovery campaigns, with emphasis on spectroscopy, and advancements in space transportation and autonomous robotic technology are crucial to future success of NEA resource utilization. LA-ICP-MS was used to evaluate main-group pallasites (PMG) for PGE potential. Bulk metal concentrations of most PGEs are lower than in iron meteorites, making the associated parent body(ies) of the PMG suboptimal for resource utilization. Average subsolidus partition coefficients are 1 < DT/K(Ir) < DT/K(Pt) ≈ DT/K(Os) < DT/K(Rh) < DT/K(Ru) < DT/K(Pd) and appear to be applicable to all instances of taenite/kamacite, regardless of parent body conditions. Keywords Space resource utilization, asteroid mining, platinum group elements, highly siderophile elements, subsolidus partitioning, pallasite, taenite, kamacite. i Co-Authorship Statement Joe Petrus, the LA-ICP-MS Laboratory Technician at the Chemical Fingerprinting Laboratory at Laurentian University, is considered a coauthor for chapter 3 of this thesis. He performed major and trace elemental analyses on the taenite and kamacite phases of all six pallasite main- group samples used in this study. The samples and the external reference material North Chile were provided by Liam Innis, as were the analysis locations and the list of elements to be detected. The details of the procedure, including spot size, dwell time, etc., were at Joe Petrus’ discretion. He was also responsible for the internal standardization, PGE interference correction, and data reduction. Lastly, he provided revisions for the portion of the methods section pertaining to the LA-ICP-MS procedure and the analytical accuracy portion of the discussion. The remainder of this thesis was written in its entirety by Liam Innis with revisions from supervisor Dr. Gordon Osinski. ii Dedication For my parents, Megan and John Thank you for your unwavering support & For Bob You were not able to see me complete this work, but I hope it would have made you proud iii Acknowledgments Thesis writing, like child rearing, takes a village. I would like to thank, in no particular order; my supervisor, Dr. Gordon Osinski, for his guidance and feedback; Dr. Phil McCausland, for his assistance in cutting pallasite samples; Marc Beauchamp, for his assistance and expertise on the EPMA; and Joe Petrus, for his excellent LA-ICP-MS analysis and co-authorship. I would like to thank Dr. Tony Withers and Dr. Robert Linnen for helpful conversations about diffusion. I would also like to thank Dr. Kim Tait, Brendt Hyde, and the Royal Ontario Museum for the use of their meteorites. Finally, I would like to thank my fellow students – in Dr. Osinski’s lab group and out – for their support, advice, and camaraderie throughout the last two years. iv Table of Contents Abstract ................................................................................................................................ i Co-Authorship Statement.................................................................................................... ii Dedication .......................................................................................................................... iii Acknowledgments.............................................................................................................. iv Table of Contents ................................................................................................................ v List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix List of Acronyms ................................................................................................................ x 1 Background and Outline ................................................................................................ 1 1.1 Introduction ............................................................................................................. 1 1.2 Outline of Thesis ..................................................................................................... 5 1.3 References ............................................................................................................... 5 2 Near-Earth Asteroid Resources: A Review ................................................................... 8 2.1 Introduction ............................................................................................................. 8 2.2 Asteroid Characteristics .......................................................................................... 9 2.2.1 Orbital Families .......................................................................................... 9 2.2.2 Spectral Types ........................................................................................... 11 2.2.3 Spectral Class Distribution ....................................................................... 14 2.3 Meteorites as Analogues ....................................................................................... 14 2.3.1 Meteorite Taxonomy ................................................................................. 15 2.4 Asteroid Resources ............................................................................................... 17 2.4.1 The Short Term ......................................................................................... 18 2.4.2 The Long Term ......................................................................................... 26 2.5 Logistics ................................................................................................................ 27 2.5.1 Discovery and Characterization ................................................................ 28 v 2.5.2 Harvesting and Transportation .................................................................. 31 2.5.3 Extraction .................................................................................................. 33 2.6 Asteroid Mining and the Law ............................................................................... 35 2.6.1 International Space Law ........................................................................... 35 2.6.2 National Legislation .................................................................................. 38 2.7 State of the Asteroid Mining Industry .................................................................. 39 2.8 Private-Public Partnerships ................................................................................... 40 2.9 Opportunities for Canada ...................................................................................... 41 2.10 Future Work ......................................................................................................... 42 2.11 References ............................................................................................................ 43 3 Abundance and Subsolidus Diffusion of Highly Siderophile Elements in Main Group Pallasites: Application to Asteroid Resource Prospecting ........................................... 53 3.1 Introduction ........................................................................................................... 53 3.1.1 Pallasite Main Group Mineralogy ............................................................. 54 3.1.2 Pallasite Formation ................................................................................... 56 3.2 Methods................................................................................................................. 58 3.2.1 EPMA ....................................................................................................... 58 3.2.2 LA-ICP-MS............................................................................................... 58 3.2.3 Taenite-Kamacite Partition Coefficients................................................... 60 3.2.4 Bulk Metal Composition