Evidence for mantle exhumation since the early evolution of the slow-spreading Gakkel Ridge, Arctic Ocean

•Rotated basement blocks define the crustal architecture in the Eurasia Basin from the initial opening onwards.•We propose that predominantly exhumed serpentinized mantle forms the basement in the Eurasia Basin, at least at the studied sector.•Detachment faults that expose rocks from deep below the slow-spreading mid-ocean ridge are proposed, maintaining a process of mantle exhumation.