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Title

Precambrian plate tectonics: criteria and evidence

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By pa cawood · 2006 · cited by 294 — evidence for pre-neoproterozoic subduction,. ophiolites, and seafloor spreading. the paleoproterozoic trans-hudson orogen in canada, the.
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4 JULY 2006, GSA TODAYABSTRACTPaleomagnetic, geochemical, and tectonostratigraphic dataestablish that plate tectonics has been active since at least3.1 Ga. Reliable paleomagnetic data demonstrate differentialhorizontal movements of continents in Paleoproterozoic andArchean times. Furthermore, the dispersal and assembly ofsupercontinents in the Proterozoic requires lateral motion oflithosphere at divergent and convergent plate boundaries. Well-preserved ophiolites associated with island-arc assemblages andmodern-style accretion tectonics occur in the PaleoproterozoicTrans-Hudson orogen of the Canadian Shield, the Svecofen-nian orogen of the Baltic Shield and in the Mazatzal-Yavapaiorogens of southwestern Laurentia. These rocks have trace ele-ment signatures almost identical to those found in rocks ofmodern intra-oceanic arcs and include ore deposits typical ofmodern subduction settings. The discovery of Archean eclo-gites in the eastern Baltic Shield; the presence of late Archeansubduct...