The outer layer of the Earth is divided into seven large and many small plates which move relative to each other with several centimetres per year. Convergence and collision of these plates is associated with seismicity, volcanism and mountain building, a s for example the Andes and Himalayas. Divergence of plates leads to the formation of oceans. The closing and opening of an ocean at the same location is called the Wilson Cycle. For example, the Iapetus Ocean between the Norwegian margin of Baltica and t he Greenland margin of Laurentia closed by subduction and collision around 425 million years ago. This led to the formation of the Caledonide mountains and the high-pressure rocks now exposed in western Norway. Extension caused break-up of the new contine nt and the formation of the North Atlantic Ocean from around 54 million years ago. The hydrocarbon occurrences on the present-day Norwegian margin are associated with the extension prior to Atlantic opening. This project intends to develop the first large -deformation numerical model of a complete Wilson Cycle. This requires careful investigation and testing of ocean closure by plate convergence and continent collision and ocean opening by post-collisional rifting. It examines how the style of convergent m argin dynamics is affected by internal (e.g. rheology) and external (e.g. plate velocities) factors and how a convergent margin system changes once the ocean is closed and two continents collide. Later continental break-up often seems to occur at or near the former plate boundary. This project aims to understand parameters that control the localisation of extensional deformation after collision. Results of the project will provide novel insight into the mechanisms of formation of collisional orogens (such as the Caledonides), the collision and accretion of small continental fragments (such as the Tethys Cimmerian continent) and the thermal and structural development of plate margins (such as the Norwegian margin).