Meso-Neoproterozoic Rodinia supercycle

Abstract Rodinia is the purported supercontinent that existed in early Neoproterozoic time. Most currently viable Rodinia models, that is, consistent with both the geological/geochemical record and geophysical constraints from paleomagnetism and reasonable plate kinematics, include Laurentia in a central position, flanked on nearly all sides by about 6–8 other cratons. Details of the history of Rodinia formation depend critically on the ages of orogens within those bounding cratons, some of which might have closed as late as ~900 Ma. Rodinia’s initial breakup likely coincided with voluminous large igneous province emplacement at ~800 Ma, lasting until final separations as young as ~600 Ma. The Rodinian-era paleomagnetic database of reliable poles is growing steadily but still requires augmentation for most cratons. Enough poles are available in key intervals (especially c.1110 and 760 Ma) that kinematic models can be constructed that plausibly evolve toward better-established Paleozoic reconstructions. A new synthesis-based model of Rodinia assembly and breakup is briefly introduced herein, which includes Tarim craton in a “missing link” role between Laurentia and proto-Australia, as well as South China and India in their recently proposed inverted orientation near the supercontinent’s southern paleo-margin. Kinematic transitions between successive supercontinents Nuna, Rodinia, and Pangea are each postulated to contain elements of both “introverted” and “extroverted” style, depending on the paleogeographic sectors of the supercontinents and distinct temporal stages of evolution that produce megacontinents prior to supercontinents. Both of these components can be rectified within an overall mantle-convective framework of “orthoversion” whereby each supercontinent fully assembles within the subduction-girdle ~90 degrees from the centroid of its predecessor.