The role of terrane accretion in the Wilson-cycle

• Zoltán Erdős
  Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Potsdam, Germany
  erdoes@gfz-potsdam.de
• Susanne Buiter,
  Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences, Potsdam, Germany
  RWTH Aachen University, Tectonics and Geodynamics, Aachen, Germany
• Joya Tetreault
  Geological Survey of Norway, Trondheim, Norway

"The Wilson-cycle that describes the repeated opening and closure of oceanic basins has been part of the larger framework of plate-tectonics for decades. One of the most significant implications of this concept is that continental rifting frequently occurs in areas that have previously undergone a phase of continent-continent collision and orogeny. Yet, our understanding of how structural and thermal inheritance from preceding convergence affects rifting is still incomplete. Moreover, common depictions of the Wilson cycle often oversimplify oceanic basins as "empty," neglecting the presence of bathymetric highs, such as microcontinental terranes, island arcs, or oceanic plateaus, which accreted before full oceanic closure, thereby altering the subduction zone before continental collision occurs.

We use 2D thermo-mechanical numerical model experiments to investigate how the accretion of multiple microcontinental terranes with a variety of rheologies affects the closure of an oceanic basin and the collision of two continents. We then go a step further and by inverting the boundary conditions we investigate how varying degrees of thermal and structural inheritance resulting from continent-continent collision affects a subsequent phase of continental rifting."