Update 2: this post here closes this series & loops the loop with AI to the rescue.
Update 1: see here papers a decade later that point also to precambrian terranes.
My 1982 M.Sc. thesis, Regional cross section of the Southern Province adjacent to Lake Huron, Ontario: implications for the tectonic significance of the Murray Fault Zone (ResearchGate) proposed a plate-tectonic (Wikipedia) setting around 1.9 billion years ago, in the Proterozoic (late Pre-Cambrian). I proposed there to be another buried land mass south of what I called the Manitoulin Island Discontinuity. While plate tectonics was well established in the later Phanerozoic (Wikipedia) record, it took a lot longer to be accepted earlier in the geologic time scale with lot sparser rock record (see "More" at the bottom).
