The work involved the following tasks:

1) Compilation of microprobe analyses data,

2) Review/perform generic mineral classifications,

3) Perfom detailed mineral interpretations,

4) Create list of samples with sample ID, grain ID, geographical location, media sampled, organization responsible for the collection or publication of the data, and references,

5) Perform mineral counts for generic mineral groups, garnet class, ilmenite, spinel group, clinopyroxene, and a combination of KIMs most relevant to diamond exploration based on detailed mineral interpretations.

Data sources comprised 85 government and industry publications which are listed in the data sources dataset.

[Total_Calc] attribute in the microprobe analyses and mineral interpretation dataset is the sum of all reported oxides recalculated for this publication. Mineralogy ([Gen_Min] and [Det_Min] attributes) was systematically reinterpreted for all KIM minerals (i.e., olivine, garnet, clinopyroxene, spinel and ilmenite). Mineralogy for other mineral grains was reinterpreted opportunistically. For mineral reinterpretations or classifications only oxide totals between 90 to 105 wt.% were considered acceptable. Oxide minerals (e.g., spinel, chromite, ilmenite) with values above 1.00 wt. % SiO2 were considered to have silicate contamination. The mineral group counts dataset includes those analyses with [Total_Calc] between 90 to 105 wt. %. KIM related count datasets (i.e., garnet class counts, clinopyroxene counts, spinel counts, ilmenite counts, and KIM interpreted counts) only included those grains with analyses with [Total_Calc] between 98.5 and 101%.

Mineral reinterpretations were performed based on the following schemes:

Garnet:

Garnet microprobe analyses were first classified by using Grew’s Excel spreadsheet to recast analyses into end-member components by dominant valency (Grew et al., 2013). Pyrope and andradite end-members were differentiated from their Cr-bearing varieties using the scheme proposed by Dredge et al. (1996). Thus, Cr-pyrope is defined as a pyrope with Cr2O3 more than 2 wt.% and Cr-andradite is defined as an andradite with Cr2O3 more than 2 wt.%.

Garnets were also classified based on their G-class by using Creighton’s Excel add-in which relies on CaO-Cr2O3 analyses to determine garnet class according to the scheme of Grütter et al. (2004) into G0, G1, G3, G3D, G4,G4D, G5, G5D, G9, G10, G10D, G11 and G12 classes. Eclogitic and pyroxenitic garnets are included in the groups G3 and G4/G5, respectively. Peridotitic garnets are included in groups G9, G10, G11 (high Ti) and G12. The addition of the letter “D” to the end of the classification indicate a strong compositional and pressure-temperature association with diamond.

Garnets from eclogite and pyroxenite (G3/G4) were differentiated as crustal or mantle derived based on the logistic regression of Hardman et al. (2018).

Clinopyroxene:

WinPyrox software (Yavuz, 2013) was used to calculate structural formulas of microprobe analyses to determine pyroxene name, percentage of jadeite, end-member calcium Tschermak’s pyroxene, and modifiers.

A combination of Mg# (i.e., 100 x Mg/Mg+Fe+2) and Cr2O3 was used to discriminate Cr-diopside from diopside, with Cr-diopside defined as a diopside containing more than 0.5 wt% Cr2O3 and 88 Mg# (Ramsey and Tompkins, 1994; Cookenboo and Grütter, 2010).

Ilmenite:

The classification suggested by Creighton and Stachel (2008) was used to determine ilmenite name. Accordingly, ilmenite was classified as picroilmenite if MgO > 8 wt. % and as Cr-picroilmenite if Cr2O3 > 1.5 wt. % and MgO > 8 wt. %, with the remaining grains classified as ilmenite.

The discrimination plot of Wyatt et al. (2004) was used to determine if ilmenite is kimberlitic or non-kimberlitic.

Spinel:

Spinel group includes chromite, spinel (sensu stricto), magnetite and other species. Therefore, spinels were first classified by using Ferracuti's software to recast analyses into end-member components based on mineral proportions (Ferracutti et al., 2015).

Creighton’s Excel add-in was utilized to calculate Mg# and classify spinels as basaltic, kimberlite groundmass, ultramafic, or diamond inclusion (Creighton and Stachel, 2008).

Olivine:

Olivine is a very common mineral in kimberlite and mantle peridotite (Mitchell, 1989). Olivine is found in other rock types, but these rocks are rare in northern Alberta and olivine is not known to form in any sedimentary rock formation in the province. Commonly, olivine from disaggregated mantle peridotite has Mg#>91.5 (McClenaghan and Kjarsgaard, 2007).

References used for mineral classification or interpretations:

Creighton, S. and Stachel, T. (2008): An empirical chromite classification for positive identification of kimberlite in diamond exploration; 9th International Kimberlite Conference, Extended Abstracts, 9IKC‐A‐00402, 3 p.

Cookenboo, H.O. and Grütter, H.S. (2010): Mantle-derived indicator mineral compositions as applied to diamond exploration; Geochemistry: Exploration, Environment, Analysis, v. 10, p. 81–95

Dredge, L. A., Kjarsgaard, I. M., Ward, B. C., Kerr, D. E. and Stirling, J. A. R.(1996): Distribution and geochemical composition of kimberlite indicator minerals, Point Lake map area, Northwest Territories (86H); Geological Survey of Canada, Open File 3341, 21 p.

Ferracutti, G.R., Gargiulo, M.F., Ganuza, M.L., Bjerg, E.A. and Castro, S.M. (2015): Determination of the spinel group end-members based on electron microprobe analyses; Mineralogy and Petrology, v. 109, p. 153–160.

Grew, E. S., Locock, A. J., Mills, S. J., Galuskina, I. O., Galuskin, E. V., and Hålenius, U. (2013): Nomenclature of the garnet supergroup; American Mineralogist, v. 98, p. 785–811.

Grütter, H.S., Gurney, J.J., Menzies, A.H. and Winter, F. (2004): An updated classification scheme for mantle‐derived garnet, for use by diamond explorers; Lithos, v. 77, p. 841–857.

Hardman, M.F., Pearson, D.G., Stachel, T. and Sweeney, R.J. (2018): Statistical approaches to the discrimination of crust- mantle-derived low-Cr garnet – Major-element-based methods and their application in diamond exploration; Journal of Geochemical Exploration, v. 186, p. 24–35.

McClenaghan, M. B. and Kjarsgaard, B. A. (2007): Indicator mineral and surficial geochemical exploration methods for kimberlite in glaciated terrain; examples from Canada; in: Mineral deposits of Canada: a synthesis of major deposit-types, district metallogeny, the evolution of geological provinces, and exploration methods; Goodfellow, W D. Geological Association of Canada, Mineral Deposits Division, Special Publication 5, p. 983–1006.

Mitchell, R.H. (1989): Aspects of the Petrology of Kimberlites and Lamproites: some definitions and distinctions. In: J. Ross (ed.) Kimberlites and Related Rocks, v.1, Their Composition, Occurrences, Origin and Emplacement, Proceedings of the Fourth Kimberlite Conference, Perth, 1986, Geological Society of Australia Special Publication No. 14, p. 7–45.

Nimis, P. and Taylor, W.R. (2000): Single clinopyroxene thermobarometry for garnet peridotites. Part I, Calibration and testing of a Cr‐in‐Cpx barometer and an enstatite‐in‐Cpx thermometer; Contributions to Mineralogy and Petrology, v. 139, p. 541–554.

Ramsay, R.R. and Tompkins, L.A. (1994): The geology, heavy mineral concentrate mineralogy, and diamond prospectivity of the Boa Esperanca and Cana Verde pipes, Corrego D'Anta, Minas Gerais, Brazil; in: Diamonds; characterization, genesis and exploration, H.O.A. Meyer and O.H. Leonardos (ed.), Proceedings of the International Kimberlite Conference, 1991, vol. 2, p. 329–345.

Wyatt, B.A., Baumgartner, M., Anckar, E. and Grütter H. (2004): Compositional classification of “kimberlitic” and “non-kimberlitic” ilmenite; Lithos, v. 77, p. 819–840.

Yavuz, F. (2013): WinPyrox: A Windows program for pyroxene calculation classification and thermobarometry; American Mineralogist, v. 98, p. 1338–1359.