West Newfoundland was critical in developing the Wilson Cycle concept. Neoproterozoic rifting established a passive margin adjacent to the Iapetus Ocean. Ordovician (Taconian) arc–continent collision emplaced ophiolites and the thin-skinned Humber Arm Allochthon. Subsequent Devonian (Acadian) ocean closure produced basement-cutting thrust faults that control the present-day distribution of units. New mapping, and aeromagnetic and seismic interpretation, around Parsons Pond enabled the recognition of structures in poorly exposed areas.Following Cambrian to Middle Ordovician passive-margin deposition, Taconian deformation produced a flexural bulge unconformity. Subsequent extensional faults shed localized conglomerate into the foreland basin. The Humber Arm Allochthon contains a series of stacked and folded duplexes, typical of thrust belts. To the east, the Parsons Pond Thrust has transported shelf and foreland-basin units c. 8 km westwards above the allochthon. The Long Range Thrust shows major topographical expression but <1 km offset. Stratigraphic relationships indicate that most thrusts originated as normal faults, active during Neoproterozoic rifting, and subsequently during Taconian flexure. Devonian continental collision inverted the Parsons Pond and Long Range thrusts. Basement-cored fault-propagation folds in Newfoundland are structurally analogous to basement uplifts in other orogens, including the Laramide Orogen in western USA. Similar deep-seated inversion structures may extend through the northern Appalachians.

The Anticosti Basin, largely hidden beneath the Gulf of St. Lawrence, includes foreland basin successions that record multiple tectonic events associated with the Ordovician to Devonian evolution of the northern Appalachian orogen. Due to the lack of well ties and minimal onshore exposure, geophysical data must be used in mapping the offshore stratigraphy. Outcropping geologic boundaries are tied to magnetic lineaments that parallel stratigraphy. These lineaments are correlated with reflections on seismic profiles in order to interpret the subsurface. Seismic isochron maps for successive basin development episodes display differences in geometry, implying that orogenic loading varied through time. The geometry and subsidence rates recorded by the Middle Ordovician Goose Tickle Group imply that it formed in a pro‐arc setting associated with loading during arc‐continent collision that was most intense in the northern Newfoundland Appalachians. The geometry and subsidence recorded by the overlying Long Point Group imply pro‐arc loading by Taconian allochthons in the Québec segment of the orogen. Diachronous subduction polarity reversal along the margin placed the Long Point Group in a combined retro‐arc and pro‐arc setting, comparable to that experienced by parts of the north Australian margin at the present day. The uppermost Silurian to Lower Devonian Clam Bank Formation and Lower Devonian Red Island Road Formation represent foreland basin successions associated with the later Salinian and Acadian orogenies. Their consistent thickness implies a broad, shallow basin, suggesting that the lithosphere was cooler and stronger than during earlier subsidence, and are consistent with a retro‐arc setting.

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The Neoarchean marked an important turning point in the evolution of Earth when cratonization processes resulted in progressive amalgamation of relatively small crustal blocks into larger and thicker continental masses, which now comprise the ancient core of our continents. Although evidence of cratonization is preserved in the ancient continental cores, the conditions under which this geodynamic process operated and the nature of the involved crustal blocks are far from resolved. In the Superior craton, deep-crustal fault systems developed during the terminal stage of Neoarchean cratonization, as indicated by the cratonwide growth of relatively small, narrow, syn-to-late tectonic (ca. 2680–2670 Ma) sedimentary basins. The terrigenous debris eroded from the uplifted tectono-magmatic source regions was deposited as polymictic conglomerate and sand successions in fluvial-dominated basins. The composition of the sedimentary rocks in these unique basins, therefore, offers a unique record of crustal sources and depositional settings, with implications for the geodynamic processes that formed the world’s largest preserved craton. Here, we compare the geochemical compositions of sandstone samples from six sedimentary basins across the Abitibi greenstone belt and relate them to their mode of deposition, prevailing provenance, and geodynamic setting during crustal growth and craton stabilization. The sandstones represent first-cycle sediment that is poorly sorted and compositionally very immature, with variable Al2O3/TiO2 ratios and index of chemical variability values &gt;1 (average of 1.36), reflecting a large proportion of framework silicate grains. The sandstones display chemical index of alteration values between 45 and 64 (average of 53), indicating that the detritus was eroded from source regions that experienced a very low degree of chemical weathering. This likely reflects a high-relief and active tectonic setting that could facilitate rapid erosion and uplift with a short transit time of the detritus from source to deposition. Multi-element variation diagrams and rare earth element patterns reveal that the lithological control on sandstone composition was dominated by older (&gt;2695 Ma) pretectonic tonalite-trondhjemite-granodiorite and greenstone belt rocks. The sandstone units display large variations in the proportions of felsic, mafic, and ultramafic end-member contributions as a consequence of provenance variability. However, an average sandstone composition of ~65% felsic, ~30% mafic, and ~5% komatiite was observed across the basins. This observation is in agreement with recent models that predict the composition of the Neoarchean emerged continental crust for North America and supports the presence of a felsic-dominated Archean crust. The high proportion of felsic rocks in the upper crust requires continuous influx of H2O into the mantle and is best explained by subduction-related processes. In such a scenario, the detritus of the fluvial sandstones is best described as being controlled by uplifted and accreted continental arcs mainly composed of tonalite-trondhjemite-granodiorite and greenstone belt rocks.

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