Sediment source and transport along the Iberian Margin

The Iberian Margin is a dynamic margin, affected by complex sedimentary and oceanographic processes. The Mediterranean Outflow Water (MOW) is a prominent water mass that flows along the Iberian margin and interacts with the sediment on the slope. However, more information about how MOW interacts with sediment delivery, distribution, deposition along the margin is needed. In this study we combine Nd, Sr and Pb isotopes on fine-grained detrital sediments (< 63 μm) and 14C measurements in planktonic foraminifera (G. bulloides) in 25 coretop sediment samples collected along the entire Iberian Margin (from the Gulf of Cadiz to the “Cachucho” mount in the Cantabrian Sea). Nd, Sr and Pb isotopes were used to (i) identify the main source areas of terrigenous sediments coming from the Iberian Peninsula and (ii) trace the distribution of these sediments along the Iberian Margin. Additionally, 14C data in planktonic foraminifera were used to obtain radiocarbon ages, that allowed us to date the coretop sediments. Results from Nd, Sr and Pb isotopes allow us to identify three main terrigenous sediment source provinces in the Iberian margin, depicting a prominent south to north gradient. Moreover, large age discrepancies in coretop sediments are strongly associated with the main pathway of MOW, thus suggesting erosion and lateral transport of sediments along the main path of the MOW.