The Mohorovicic discontinuity or 'Moho' maps the boundary between the earth's crust and mantle and is defined by an abrupt change in seismic velocity due to changes in the density of rocks between the crust and mantle. GeoTIFF grids that map depth to Moho (crustal thickness) for the United States and Canada, and for Australia are provided in this report and were used as evidential layers in developing prospectivity models for basin-hosted Pb-Zn mineralization (Lawley and others, 2022). A composite grid of Moho depths across the United States and Canada was created using data from Shen and Ritzwoller (2016) for the conterminous United States, from Zhang and others (2019) for Alaska, and from Schetselaar and Snyder (2017) for Canada. For this study, data covering North America were gridded onto a 0.25 degree grid and merged to create the composite grid across the United States and Canada. A grid of depth to Moho for Australia is from Kennett and others (2011). The GeoTiff grid of Moho for Australia is provided here as a courtesy for completeness of the model. The original data sources should be cited specific to the area covered. References Kennett, B.L.N., Salmon, M., Saygin, E., and AusMoho Working Group, 2011, AusMoho: The variation of Moho depth in Australia: Geophysical Journal International, v. 187, no. 2, p. 946-958, https://doi.org/10.1111/j.1365-246X.2011.05194.x. Lawley, C.J.M., McCafferty, A.E, Graham, G.E., Huston, D.L., Kelley, K.D., Czarnota, K., Paradis, S., Peter, J.M., Hayward, N., Barlow, M., Emsbo, P., Coyan, J., San Juan, C.A., and Gadd, M.G., 2022, Data-driven prospectivity modelling of sediment-hosted Zn-Pb mineral systems and their critical raw materials: Ore Geology Reviews, v. 141, no. 104635, https://doi.org/10.1016/j.oregeorev.2021.104635. Schetselaar, E.M., and Snyder, D.B., 2017, National database of Moho depth estimates from seismic refraction and teleseismic surveys: Natural Resources Canada Open File 8243, https://doi.org/10.4095/305396. Shen, W., and Ritzwoller, M.H., 2016, 3D shear-wave velocity model of the US from joint inversion of surface wave dispersion from ambient noise and earthquakes, Rayleigh wave H/V ratio, and receiver functions: Incorporated Research Institutions for Seismology, https://doi.org/10.17611/DP/EMCUS2016. Zhang, Y., Li, A., and Hu, H., 2019, Crustal structure in Alaska from receiver function analysis: Geophysical Research Letters, v. 46, no. 3, p. 1284-1292, https://doi.org/10.1029/2018GL081011.