Onset, evolution and effects of the Mediterranean outflow; preliminary results of IODP Expedition 339 in the Gulf of Cadiz

Author(s): Stow, Dorrik; Hernández-Molina, F. Javier; Alvarez-Zarikian, Carlos
Author Affiliation(s): Primary:
Heriot-Watt University, Edinburgh Collaborative of Subsurface Science and Engineering, Edinburgh, United Kingdom
Other:
Universidad de Vigo, Spain
Texas A&M University, United States
Volume Title: 34th international geological congress; abstracts
Source: International Geological Congress [International Geological Congress, Abstracts = Congrès Géologique International, Résumés, Vol.34, p.126; 34th international geological congress, Brisbane, Queensl., Australia, Aug. 5-10, 2012. Publisher:], [location varies], International CODEN: IGABBY
Note: In English
Summary: IODP Expedition 339 drilled 5 sites in the Gulf of Cadiz and 2 off the west Iberian margin (November 2011 to January 2012), and recovered 5.5 km of core with an average recovery of 86.4%. The Gulf of Cadiz is a key location for the investigation of Mediterranean Outflow Water (MOW) through the Gibraltar Gateway and its influence on global circulation and climate. It is also a prime area for understanding the effects of tectonic activity on evolution of the Gibraltar Gateway and on margin sedimentation. A strong signal of MOW in the Gulf of Cadiz sedimentary record following opening of the Gibraltar Gateway is identified. Significant widespread unconformities are interpreted as a signal of intensified MOW. The Quaternary succession shows a pronounced phase of contourite drift development, with two periods of MOW intensification separated by a widespread unconformity, when the present sea-floor contourites features were established. There is a significant climate control on this evolution of MOW and bottom-current activity. However, there has been an even stronger tectonic control on margin development, downslope sediment transport and contourite drift evolution. Based on the timing of events recorded in the sedimentary record, we propose a tectonic pulsing in the region, linked with asthenosphere activity. The Gulf of Cadiz is the world's premier contourite laboratory and thus presented an ideal testing ground for the contourite paradigm. An enormous quantity and extensive distribution of contourite sands were verified, which represent a completely new and important exploration target for potential oil and gas reservoirs.
Year of Publication: 2012
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Atlantic Ocean; Climate change; Climate effects; Cores; Currents; Expedition 339; General circulation models; Gulf of Cadiz; Integrated Ocean Drilling Program; Marine sediments; Marine transport; Mediterranean Sea; North Atlantic; Ocean circulation; Ocean currents; Sediments; Transport; West Mediterranean
Coordinates: N361605 N373418 W0064700 W0100735
Record ID: 2016039084
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