The opening and closure of the Palaeozoic oceans that lay between equatorial Laurentia and the southern polar Gondwana continue to fascinate geologists. The geological history of this region would have been simpler if there had only been one ocean between these two continents. As we now know, there was one other major continent (Baltica) and over a dozen microcontinents that complicated the intervening area. Most of these fragments were rifted off the Gondwanan margin and drifted northward to accrete with Laurentia. Baltica and the archipelago comprising the RhenoHercynian zone and Avalonia separated two oceanic branches. For a time, the research community was preoccupied with the northern branch, the Iapetus Ocean. More recently, attention has shifted to the southern branch, the Rheic Ocean, whose closure culminated in the Late Palaeozoic Variscan Orogeny.

International Geological Correlation Program (IGCP) Project 497 has done much to coordinate research on remnants of the Rheic Ocean and its margins, now scattered across five continents. The present volume collects together research papers given at five meetings of this project held between September 2004 and July 2005. As is usual with such compilations, there is a mixture of content from reviews of substantial parts of the orogen to detailed studies of one small sector. However, the geographical spread is very broad. Iberia and the Mexican terranes are best represented (five papers each), with strong showings from the Saxothuringian and Barrandian zones (four papers each) and from South America (three papers). Other areas are represented by single papers only: Western Avalonia, Far Eastern Avalonia, Armorica, Baltica, North Africa, the Proto-Alpine terranes and Siberia. The volume will naturally arrive in many libraries as part of the Geological Society of America's special paper series. Geologists who work on Palaeozoic palaeogeography and tectonics will certainly want access to a copy.