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In recent years, short-lived mantle generated magmatic events, particularly large igneous provinces (LIPs) and their dyke swarms, have emerged as the key tool in paleogeographic reconstructions. Major magmatic events store an incredibly diverse range of high-quality information, punctuating Earth history at an average frequency of ∼10 events per 100 Myr, waxing and waning in tune with the supercontinent cycle-the "pulse of the Earth".
As barriers to obtaining precise and accurate age information are rapidly disappearing, these events provide, increasingly, a robust and relatively high-resolution record in time. In addition, because these events (1) have large "footprints", (2) are typically associated with initial rifting attempts, and (3) with final breakup, they naturally end up on both conjugate margins.
By dating a sufficient number of short-lived magmatic events through time, we can define a magmatic "barcodes" for any sizable fragment of continental crust. Well-populated and precisely dated barcodes are inherently less fuzzy than many other data used for testing correlations. Similarities between barcodes from different continental blocks almost certainly means that these blocks were "nearest neighbours" in an ancestral landmass. Any precise "barcode match" should be flagged and carefully evaluated. Two or more precise barcode matches, particularly if spread over a considerable interval of time (e.g. 100-200 Ma), almost certainly point to dispersal of originally contiguous continental blocks ("the rule of multiple barcode matches"). The problem then becomes one of finding the most likely configuration of the different blocks in their ancestral (super)continent or supercraton.
With a typical footprint (diameter) of a large magmatic event of ∼1000-3000 km, precise barcode matches imply original proximity on that scale. Geometrical information of major dyke swarms (dominant trend; degree and direction of convergence; flow direction; etc.) may then be sufficient to fully constrain potential reconstructions. However, other tools are available: fine-grained mafic magmatic rocks also represent target rocks of choice for careful paleomagnetic work.
The proposition to date and characterize all significant mafic magmatic events through time and space is becoming realistic. It would allow a rapid synthesis of all continental geology by providing numerous robust constraints for reconstructions of pre-Pangaean supercontinents and supercratons: ca. 1 Ga Rodinia, ca. 1.8-1.5 Ga Nuna, and large late Archean supercratons such as Superia and Sclavia.
Together with integrated paleomagnetic data, we could track the movements of continental blocks through time, thus providing constraints for various geodynamic models. With a concerted effort, this could be achieved in less than a decade, fulfilling the ultimate promise of the plate tectonic revolution, approximately 100 years after Wegener identified the youngest supercontinent in Earth history, Pangaea.
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