14
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Intra-oceanic subduction shaped the assembly of Cordilleran North America.

      1 ,
      Nature

      Read this article at

      ScienceOpenPublisherPubMed
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The western quarter of North America consists of accreted terranes--crustal blocks added over the past 200 million years--but the reason for this is unclear. The widely accepted explanation posits that the oceanic Farallon plate acted as a conveyor belt, sweeping terranes into the continental margin while subducting under it. Here we show that this hypothesis, which fails to explain many terrane complexities, is also inconsistent with new tomographic images of lower-mantle slabs, and with their locations relative to plate reconstructions. We offer a reinterpretation of North American palaeogeography and test it quantitatively: collision events are clearly recorded by slab geometry, and can be time calibrated and reconciled with plate reconstructions and surface geology. The seas west of Cretaceous North America must have resembled today's western Pacific, strung with island arcs. All proto-Pacific plates initially subducted into almost stationary, intra-oceanic trenches, and accumulated below as massive vertical slab walls. Above the slabs, long-lived volcanic archipelagos and subduction complexes grew. Crustal accretion occurred when North America overrode the archipelagos, causing major episodes of Cordilleran mountain building.

          Related collections

          Most cited references45

          • Record: found
          • Abstract: not found
          • Article: not found

          Convection Plumes in the Lower Mantle

            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Global continental and ocean basin reconstructions since 200Ma

              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Cordilleran suspect terranes

                Bookmark

                Author and article information

                Journal
                Nature
                Nature
                1476-4687
                0028-0836
                Apr 4 2013
                : 496
                : 7443
                Affiliations
                [1 ] Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Theresienstrasse 41, 80333 Munich, Germany. sigloch@geophysik.uni-muenchen.de
                Article
                nature12019
                10.1038/nature12019
                23552944
                b87b6973-76fe-445b-8ff5-e044a921b208
                History

                Comments

                Comment on this article