| Title | Tectonic evolution of the western Superior Province from NATMAP and Lithoprobe studies |
| Author | Percival, J A; Sanborn-Barrie, M; Skulski, T; Stott, G M; Helmstaedt, H; White, D J |
| Source | Canadian Journal of Earth Sciences vol. 43, no. 7, 2006 p. 1085-1117, https://doi.org/10.1139/e06-062 (Open Access) |
| Year | 2006 |
| Alt Series | Earth Sciences Sector, Contribution Series 2005771 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Ontario; Manitoba |
| Area | western Superior Province; United States |
| Lat/Long WENS | -102.0000 -85.0000 57.0000 48.0000 |
| Subjects | tectonics; structural geology; geochronology; geophysics; general geology; continental crust; oceanic crust; magmatism; Mohorovicic discontinuity; modelling; Uchi margin; North Caribou superterrane;
English River turbidites; Winnipeg River terrane; Wabigoon terrane; Shebanowanian collision; Quetico turbidites; Minnesotan orogeny |
| Illustrations | location maps; geological sketch maps; schematic representations; seismic reflection profiles; geophysical images; stratigraphic correlations |
| Program | Northern Resources Development Program |
| Abstract | Five discrete accretionary events assembled fragments of continental and oceanic crust into a coherent Superior craton by 2.60 Ga. They exhibit similar sequences of events at ~10 million year intervals:
cessation of arc magmatism, early deformation, synorogenic sedimentation, sanukitoid magmatism, bulk shortening, regional metamorphism, late transpression, orogenic gold localization, emplacement of crust-derived granites, and postorogenic cooling.
The Northern Superior superterrane recorded 3.7 - 2.75 Ga events prior to 2.72 Ga collision with the 3.0 Ga North Caribou superterrane. Following 2.98 Ga rifting, the Uchi margin of the North Caribou superterrane evolved in an upper plate setting
before 2.72 - 2.70 Ga collision of the <3.4 Ga Winnipeg River terrane, which trapped synorogenic English River turbidites in the collision zone. The Winnipeg River terrane was reworked in 2.75 - 2.68 Ga magmatic and tectonic events, including the
central Superior orogeny (2.71 - 0 Ga) that marks accretion of the juvenile western Wabigoon terrane. In the south, the Wawa-bitibi terrane evolved in a mainly oceanic setting until Shebandowanian collision with the composite Superior superterrane at
2.695 Ga. Synorogenic Quetico turbidites were trapped in the collision zone. The final accretionary event involved addition of the Minnesota River Valley terrane (MRVT) from the south, and deposition and metamorphism of synorogenic turbidites of the
Pontiac terrane during the ~2.68 Ga Minnesotan orogeny. Seismic reflection and refraction images indicate north-dipping structures, interpreted as a stack of discrete 10-15 km thick terranes. A slab of high-velocity material, possibly representing
subcreted oceanic lithosphere, as well as Moho offsets, support a model of progressive accretion through plate-tectonic-like processes. |
| GEOSCAN ID | 221874 |
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