Measuring the pulse of a plume with the sedimentary record

Abstract

Magmatic underplating associated with mantle plume activity is an important mechanism for driving regional surface uplift and denudation of large portions of the continents1,2. Such uplift occurs rapidly because substantial volumes of basaltic melt are added to the crust over geologically short periods of time (1–10 Myr)2, and can lead to large amounts of clastic sediment being shed into surrounding basins3. An intensively studied example of this process occurred in the North Sea basin during the Palaeogene period, where discrete pulses of deposition were triggered when sands were remobilized downslope from the shelf by turbidity currents and debris flows as a result of episodic changes of relative sea level3. Here we correlate the timing of these sediment pulses with the timing of surface uplift inferred to have been caused by episodic magmatic underplating on the continental shelf of northwestern Europe. This magmatism was related to activity of the Iceland plume, suggesting that individual pulses of sedimentation provide a potentially sensitive measure of plume activity, and so may be used to resolve time-dependent fluctuations in mantle plume activity predicted by theoretical studies of mantle convection.