A charcoal-rich horizon at Ø69, Greenland: evidence for vegetation burning during the Norse landnám?

It is often assumed that the colonisation of Greenland by Norse settlers in c. A.D. 985 had a sudden and dramatic effect on the environment, involving substantial vegetation clearance and environmental degradation. Consequently, it has been argued that charcoal-rich horizons, visible in many sections in Greenland, represent the initial burning of the vegetation by Norse farmers to create land suitable for agriculture. In this study a charcoal-rich layer, visible in a modern drainage ditch beside the Norse farm of Ø69, was analysed using archaeobotany, sedimentary analysis and radiocarbon dating to test the date and formation processes of the horizon. It is demonstrated that the charcoal-rich layer at Ø69 was not derived from in situ vegetation burning in the 10th century and concluded that the layer was probably formed by the addition of midden material to the infields around Ø69 in the 13th and 14th centuries cal AD, perhaps as part of a soil amendment strategy. It is argued that caution must be exercised when interpreting charcoal-rich horizons as time-specific chronological markers in palaeoenvironmental sequences in Greenland.