Models of greenstone belt development are crucial for exploration. Allochthonous models predict belts to be a collage of unrelated fragments, whereas autochthonous models allow for prediction of syngenetic mineral deposits within specific stratigraphic intervals. Superior province greenstone belts consist of mainly volcanic units unconformably overlain by largely sedimentary "Timiskaming-style" assemblages, and field and geochronological data indicate that the Abitibi greenstone belt developed autochthonously. We describe major revisions to stratigraphy of the Abitibi greenstone belt and the implications of an autochthonous development of the volcanic stratigraphy for exploration for syngenetic mineralization. The Abitibi greenstone belt is subdivided into seven discrete volcanic stratigraphic episodes on the basis of groupings of numerous U-Pb zircon ages of pre

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An extensive set of north- to northwest-trending diabase dykes, termed the Lac Esprit swarm, is identified in the Superior Province east of James Bay based on geological mapping and a distinctive paleomagnetic pole (61.7°N, 169.1°E, dm = 7.7°, dp = 5.5°). The Lac Esprit swarm yields a U–Pb baddeleyite age of 2069 ± 1 Ma similar to that of the 2076+5–4 Ma Fort Frances swarm of the western Superior Province. Their paleomagnetic declinations differ by 23° ± 12° after correction to a common reference locality. The difference is likely due mainly to counterclockwise rotation about a vertical axis of the Fort Frances area relative to the Lac Esprit area. Differential rotation of 10°–20° has been proposed more locally across the Kapuskasing Structural Zone separating the eastern and western Superior Province in earlier paleomagnetic studies of ca. 2450 Ma Matachewan and 2170 Ma Biscotasing dyke swarms. Thus, relative rotation may have involved the entire eastern and western Superior Province, perhaps in response to collisional events associated with the Trans-Hudson Orogen to the north or the Penokean orogen to the south, or in response to rifting beneath Hudson Bay. Other dykes in the study area are interpreted from a combination of paleomagnetism, trend, and geochemistry to belong to the Senneterre, Matachewan, and Mistassini swarms. The 2216 Ma Senneterre dykes form part of a giant swarm that fans across the eastern Superior Province. Paleomagnetic directions and geometry of this swarm rule out substantial block rotations within the eastern Superior Province since dyke emplacement.

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