@Article{Gordon:2005, author = {S.M. Gordon and D.A. Schneider and M. Manecki and D.K. Holm}, title={Exhumation and metamorphism of an ultrahigh-grade terrane: geochronometric investigations of the {S}udete {M}ountains ({B}ohemia), {P}oland and {C}zech {R}epublic}, journal={Jour. Geol. Soc. Lond.}, year={2005}, volume={162}, number={}, month={Sep}, pages={841--855}, note={}, annote={}, keywords={Bohemian Massif; ultrahigh pressure; exhumation; monazite; geochronology}, url={http://sims.ess.ucla.edu/PDF/Gordon_et_al_2005_GSL.pdf}, doi={10.1144/0016-764904-078}, abstract={The Sudete Mountains, NE Bohemian Massif (Czech Republic and Poland), preserve abundant eclogitic and granulitic centimetre- to decimetre-scale boudins enveloped in a predominantly migmatitic matrix. Published geochronometry and thermobarometry from the UHP and UHT rocks broadly constrain the crystallization and initial stage 1 exhumation history for these units; however, the timing of stage 2 metamorphism and associated unroofing is less well constrained. New in situ ion microprobe Th-Pb monazite results, together with complementary U-Pb zircon and electron microprobe analyser total-Pb monazite results, on 11 amphibolite-facies gneissic to migmatitic samples, place important temporal constraints on the second stage of UHP and UHT metamorphism-exhumation. The Orlica-Snieznik Dome records UHP metamorphism occurring at 375 Ma and subsequent exhumation to midcrustal levels in supra-Barrovian conditions at c. 345-330 Ma. In contrast, the western G\'{o}ry Sowie Block preserves evidence of HP-granulite conditions at c. 400 Ma, and exhumation to mid-crustal levels at 380-370 Ma, revealing a c. 30 million years difference in exhumation events between the neighbouring terranes. The eastern G\'{o}ry Sowie Block preserves ages similar to the Orlica-Sneiznik Dome, suggesting that different preserved metamorphic-cooling histories are juxtaposed across the Sudetic Marginal fault. The bounding Niemcza shear zone yields preliminary Th-Pb dates that range from 380 $\pm$ 8 Ma to 283 $\pm$ 2 Ma, preserving a protracted metamorphic record that spans the exhumation history of the region. The distinct collapsed geochronologies of both terranes probably reflect rapid vertical transport of low-viscosity crust under supra-Barrovian conditions near the mid-crustal high-strength lid during oblique (transpressional) convergence.} }