Tectonometamorphic evolution along the Iapetus suture zone in Newfoundland: Evidence for polyphase Salinic, Acadian and Neoacadian very low- to medium-grade metamorphism and deformation

In contrast, rocks along the southern transect through the RIL zone mainly show Acadian ages of 408-390 Ma with local preservation of older ages. Acadian deformation occurred under low temperature/low pressure conditions (~250-450 °C, 2.5-4.6 kbar). Also Silurian terrestrial cover rocks were buried under these conditions. Acadian-Neoacadian deformation (393-340 Ma) becomes younger towards the northwest and progressively localized in transcurrent fault zones. This final foreland deformation at shallow crustal level established the Acadian/Neoacadian orogenic front in central Newfoundland slightly northwest of the RIL.