The geodynamics of the marginal areas of the Arctic Ocean are a supraregional focus of Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), and are investigated by CASE (Cirum-Arctic Structural Events) projects. The 3rd CASE-workshop took place at the BGR, Hannover, from 13th to 16th of March 2017. Participants came from across Europe, Scandinavis, Russia, and USA. Presentations included Pre-Caledonian events, breakup of Laurasia, fieldwork, mapping methods and Mesozoic/Cenezoic magmatic events. Christian gave a talk entitled 'High arctic volcanism, mantle sources'