Grain size, magnetic susceptibility and radiocarbon data for sediment cores MD07-3114 and MD07-3115, Aysén Fjord, Chilean Patagonia

Two Calypso sediment cores (MD07-3114 and MD07-3115) were taken in the outer Aysén Fjord during the PACHIDERME survey in February 2007 on board RV Marion-Dufresne. Both cores were scanned using the on-board multi-sensor core logger for magnetic susceptibility at a 2 cm interval. Grain-size distributions were measured using a Malvern Mastersizer 3000 after chemical pre-treatment to remove organic matter, calcium carbonate and biogenic silica and thus isolate the terrigenous fraction. A sampling resolution of 20 cm was applied throughout core MD07-3114 and increased to 10 or even 5 cm in specific areas of interest. Only the first 3.5 m of core MD07-3115 were sampled for grain-size analysis, with samples retrieved every 4 cm (when possible). Grains with a diameter larger than 1 mm were excluded for analysis by sieving. Radiocarbon ages for selected depths in both cores have been obtained using a combination of plant remains and shells. Samples were measured at the National Ocean Sciences Accelerator Mass Spectrometer (NOSAMS) facility of the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts and the Leibniz AMS facility of the Christian Albrechts University in Kiel, Germany. All radiocarbon ages were corrected for 13C. A reservoir age of 550 years is considered for the marine samples, to which we add an uncertainty of 40 years—corresponding to the average error on the radiocarbon ages themselves.