Preliminary Results of IODP Expedition 339 „Mediterranean Outflow“

was the contourite depositional system in the Gulf of Cádiz and off the West Iberian margin as a key location for the investigation of the Mediterranean Outflow Water (MOW) and its influence on North Atlantic circulation and climate. The Gulf of Cádiz is the world’s premier contourite laboratory and presents a unique opportunity to test current models of contourite formation. it is also a prime target for understanding the effects of tectonic activity on the evolution of the Strait of Gibraltar and on margin sedimentation. Overall, IODP Exp. 339 had five major objectives: 1) Understand the opening of the Gibraltar Gateway and onset of MOW. 2) Determine MOW paleocirculation and global climate significance. 3) Establish a marine reference section of Quaternary climate change. 4) Identify external controls on sediment architecture of the Gulf of Cadiz and Iberian margin. 5) Ascertain synsedimentary tectonic control on architecture and evolution of the contourite depositional system. To meet these objectives, five sites were drilled in the Gulf of Cádiz (U1386, U1387, U1388, U1389, and U1390) and two sites off the West Iberian margin (U1385 and U1391) (Fig. 1), with the deep Site U1385 located outside the main core of the MOW. A total of 5447 m of core were recovered (86.4 % recovery), and downhole logging was performed in all but two sites (U1385 and U1388)