Boundaries of mantle-lithosphere domains in the Bohemian Massif as extinct exhumation channels for high-pressure rocks

摘要: Abstract Five domains (microplates) have been recognized by seismic anisotropy in the mantle lithosphere of Bohemian Massif. The correspond to major crustal units and each bears a consistent fossil olivine fabric formed before their Variscan assembly. present-day indicates that this process consisted at least three oceanic subductions, followed an underthrusting continental lithosphere. does not detect remnants but it can trace boundaries preserved subsequently underthrust along paths previous subductions. most robust continent–continent collision was westward Brunovistulian lithosphere, still detectable more than 100 km beneath Moldanubian Major occurrences high-pressure/ultra high-pressure (HP–UHP) rocks follow ENE NNE oriented sutures mantle–lithosphere mapped from three-dimensional modeling body-wave anisotropy. HP–UHP are products subductions following crust exhumed boundaries. close relation near paleosubductions testifies for models interpreting granulite–garnet peridotite association oceanic/continental subduction/underthrusting exhumation deep-seated rocks. Our findings support bivergent subduction model tectonic development central part inferences image Massif as mosaic microplates with rigid preserving fabric. collisional boundaries, blurred tectonometamorphic processes easily deformed overlying crust, served channels