A Caledonian age for reflectors within the mantle lithosphere north and west of Scotland

摘要: This paper synthesizes geophysical data from two areas north and west of the Scottish mainland, sites grids composed over 1600 650 line km, respectively, deep (≥15 s two-way travel time) seismic reflection profiles. These make possible migration generally eastward-dipping reflections in order to locate correctly three dimensions reflector surfaces within uppermost mantle lithosphere. North Scotland part surface strikes northwest forms a plunging fold structure that arches several kilometers into lower crust near its hingeline. At depths around 50 km splits surfaces, one subhorizontal dipping east. Gravity modeling suggests this latter may be normal fault or shear zone therefore Permo-Triassic extensional features superposed on older, reflectors. Similarities patterns observed both lead us suggest these come parts once continuous 700 long. Late Caledonian age left-lateral offsets 200 are inferred have disrupted structure. Restoration offset plus tens subsequent extension recreates an feature parallel erogenic front toward suture along Laurentian plate margin. If our restoration is correct assuming regional-scale coupling between crustal faulting deformation, some structures persisted for 400 Ma. Eclogite metasomatized rock zones hundred meters thick appear likely sources impedance contrast producing reflections.