Late Paleoproterozoic to mid-Neoproterozoic history of northern Laurentia: An overview of central Rodinia

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Abstract At the assumed core of reconstructed Rodinia, northern Laurentia, comprising the Canadian Shield (including Greenland) and its buried western and northern extensions beneath Phanerozoic cover, is considered in two parts. On its southeast side, the Grenville Province is part of a major late Mesoproterozoic orogen inferred to be related to the assembly of the Rodinia supercontinent. The remainder of northern Laurentia experienced a long period of crustal stability beginning at ca. 1.8 Ga, recorded for the most part by intracontinental and passive-margin sedimentation along with mafic igneous activity, mainly in the mid-Mesoproterozoic, related to limited extension. To the south, this stable part of northern Laurentia is overprinted by late Paleoproterozoic orogeny (Yavapai, Mazatzal, and Central Plains orogens) and early Mesoproterozoic magmatism (granite-rhyolite provinces). Deformed and metamorphosed rocks related to these form a major part of the interior of the Grenville orogen, where mid- to late Mesoproterozoic orogenic events led to accretion of terranes to Laurentia and subsequent terminal collision. The first manifestation of Rodinia breakup began in the west at ca. 0.8 Ga, some 0.2 Ga earlier than along the southeast side; the age of initial rifting along the northern margin is not known.