The existence of Iceland is the result of anomalously high melt production due to the interaction of the Iceland plume with the North Atlantic mid ocean ridge. Due to the young age of the Icelandic crust, radiogenic isotopic ratios have not been significantly changed from their original source value and so provide insight into the composition of the mantle beneath Iceland. Hence Iceland provides a unique natural laboratory to investigate the composition and structure of a mantle plume. High-precision isotopic and chemical data are being used to characterize the nature and distribution of recycled components in the Iceland plume, and investigate interactions with crustal materials and the surrounding North Atlantic Asthenosphere