Dr. Jacob Forshaw
Metamorphism of pelites, with an emphasis on the Whetstone Lake area, Ontario
Jacob studied the thermodynamic modelling of mafic granulites for his MSc degree at Oxford, which formed the basis for his first publication. At Calgary, he examined the metamorphism of the broadly pelitic rocks (metamorphosed clastic sediments and metamorphosed altered volcanics) of the Barrovian (Grt-St-Ky-Sil) Whetstone Lake area, Ontario, made famous by a series of papers by Dugald Carmichael in the 1970s. Jacob documented the extraordinary range of bulk compositions and mineral assemblages of these rocks, and used these to test the ability of thermodynamic models to predict the phase relations. To put these rocks in context, and to aid in the modelling, he first did global assessments of the bulk composition of pelitic rocks, and of Fe2+/Fe3+ in minerals in pelitic rocks.
Selected publications:
Forshaw, J.B., Hartmeier, P., Pattison, D.R.M., Tamblyn, R., Starr, P.G. & Lanari, P. (submitted) Equilibrium and disequilibrium processes in metapelites: insights from major-element compositions in the staurolite-andalusite sequence at Harpswell, Maine. Journal of Petrology.
Pattison, D.R.M. & Forshaw, J.B. (submitted) Contact-metamorphosed to regionally-metamorphosed pelites: the natural record. “Perspectives” article in Journal of Petrology.
Forshaw, J.B. & Pattison, D.R.M. (2023) Bulk Compositional Influence on Diverse Metapelitic Mineral Assemblages in the Whetstone Lake Area, Ontario. Journal of Petrology 64, 1-29. pdf https://doi.org/10.1093/petrology/egad071
Forshaw, J.B. & Pattison, D.R.M. (2023) Major-element geochemistry of pelites. Geology 51, 39-43. pdf
Gopon, P., Forshaw, J.B., Waters, D.J., Wade, J. (2022) Seeing through metamorphic overprints in the Lewisian Complex of Scotland using two-pyroxene single crystal thermometry. American Mineralogist. doi: https://doi.org/10.2138/am-2022-8214CCBY
Forshaw, J.B. & Pattison, D.R.M. (2021) Ferrous/Ferric (Fe2+/Fe3+) partitioning among silicates in metasedimentary rocks. Contributions to Mineralogy and Petrology 176. 26 pages. doi.org/10.1007/s00410-021-01814-4. pdf
Pattison, D.R.M., Forshaw, J.B., Lanari, P., Caddick, M.J., Waters, D.J. & Tinkham, D.K. (2021). Phase equilibrium modelling: approaches and pitfalls. Report on the on-line meeting. Elements 11(3): 216-217. pdf link to workshop website and presentations
George F.R., Waters D.J., Gough S., Searle M.P., and Forshaw, J.B., 2021, Phase equilibria and microstructural constraints on the high temperature building of the Kohistan island arc: the Jijal garnet granulites, northern Pakistan. Journal of Metamorphic Geology. https://doi.org/10.1111/jmg.12622
Ambrose, T.K, Waters, D.J., Searle, M.P., Gopon, P., and Forshaw, J.B., 2021, Burial, accretion and exhumation of the Oman-UAE metamorphic sole. Tectonics, 40(4). https://doi.org/10.1029/2020TC006392
Forshaw, J.B., Waters, D.J., Pattison, D.R.M., Palin, R.M. & Gopon, P. (2019) A comparison of observed and thermodynamically predicted phase equilibria and mineral compositions in mafic granulites. Journal of Metamorphic Geology 37, 153-179. pdf