Did a proto-ocean basin form along the southeastern Rae cratonic margin? Evidence from U-Pb geochronology, geochemistry (Sm-Nd and whole-rock), and stratigraphy of the Paleoproterozoic Piling Group, northern Canada
N. Wodicka et al., Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada. Published online 16 July 2014; http://dx.doi.org/10.1130/B31028.1.
Approximately two billion years ago, an extensive sedimentary basin formed along the southern margin of the ancient Rae craton in northern Canada. This study uses field observations and analytical tools to elucidate the formation and evolution of the northeastern-most portion of this sedimentary basin, the Piling Group on Baffin Island, with the aim of deciphering the geological evolution of the underlying crust. The Piling Group contains deep marine turbidite deposits not observed in time-equivalent, intracratonic basin units further southwest. The work suggests that a proto-ocean basin formed off the southeastern coast of the Rae craton at about 1.92 billion years ago allowing for the deposition of 3-5 km thick turbidite deposits. Subsequent mantle upwelling may have triggered melting of highly thinned continental crust. The results are consistent with the much debated model of asthenospheric upwelling and incipient rifting along the Rae-Hearne boundary (Snowbird Tectonic Zone) farther southwest.
Calibration of a conodont apatite-based Ordo
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Geological Society of America