Ascent of the ultrahigh-pressure Western Gneiss Region, Norway
Published:January 01, 2007
Bradley Hacker, 2007. "Ascent of the ultrahigh-pressure Western Gneiss Region, Norway", Convergent Margin Terranes and Associated Regions: A Tribute to W.G. Ernst, M. Cloos, W.D. Carlson, M.C. Gilbert, J.G. Liou, S.S. Sorensen
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Ca. 415–400 Ma ultrahigh-pressure (UHP) eclogites in the Western Gneiss Region of Norway occur in three discrete ∼2500 km2 to >100 km2 antiformal domains separated by high-pressure rocks. Disparate eclogite ages suggest that the northern UHP domain and the two southern UHP domains are separate crustal blocks that experienced and were exhumed from UHP conditions at different times. The UHP rocks underwent isothermal decompression to <20 km depth in ∼5 m.y., suggesting adiabatic exhumation of a >20–30 km thick UHP body. The UHP slab rose coherently from mantle to crustal depths and was exhumed through the crust progressively from east to west between 400 and 390 Ma.