Figure 1

Reconstruction of the South Scandinavian Caledonides. E-W profile across the Bergen Arcs (1:1, horizontal-vertical scale) at 430 Ma, prior to the final continental Scandian collision. The leading edge of the Jotun-Lindås microcontinent is buried beneath the accreted outboard ophiolite/island arc terrains in the west, while it is thrust upon the hyperextended margin of Baltica in the east. The eclogitized and amphibolitised shear zones in the Lindås nappe formed at this stage, before the main continent-continent collision between Baltica and Laurentia. The onset of the Himalayan-type continental convergence occurred in the Lower Devonian and eventually produced regional high-to ultra-high-pressure metamorphism in the Baltic basement at 410 ± 10 Ma. A 1.8 GPa isobar is shown on the inset map.