Caledonian Variscan and Appalachian mountain belts, now disrupted on both sides of the Atlantic ocean, once formed the largest orogenic system of Pangea. These paleoAtlantic orogenic systems, formed during closure of Iapetus and partly during closure of Rheic, share striking common or contrasting features.This sessions aims at gathering together geologists, geophysicists and modelers interested in correlations, comparisons of those lithospheric scale structures and their bearing on our understanding of universal processes such as how margins were first shaped by rifting, break-up and coeval magmatism, then afected by ocean closure, ophiolite obductions and eventually definitive suture, continental subduction and collision. Their heritage and their control on the later evolution of Tethyan Europe or Eastern North America also have to be considered in their comprehensive knowledge.