ORCID Profile
0000-0002-3785-3336
Current Organisation
Texas A&M University
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Publisher: Copernicus GmbH
Date: 05-11-2013
DOI: 10.5194/SD-16-1-2013
Abstract: Abstract. IODP Expedition 339 drilled five sites in the Gulf of Cadiz and two off the west Iberian margin (November 2011 to January 2012), and recovered 5.5 km of sediment cores with an average recovery of 86.4%. The Gulf of Cadiz was targeted for drilling as 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. We penetrated into the Miocene at two different sites and established a strong signal of MOW in the sedimentary record of the Gulf of Cadiz, following the opening of the Gibraltar Gateway. Preliminary results show the initiation of contourite deposition at 4.2–4.5 Ma, although subsequent research will establish whether this dates the onset of MOW. The Pliocene succession, penetrated at four sites, shows low bottom current activity linked with a weak MOW. Significant widespread unconformities, present in all sites but with hiatuses of variable duration, are interpreted as a signal of intensified MOW, coupled with flow confinement. The Quaternary succession shows a much more pronounced phase of contourite drift development, with two periods of MOW intensification separated by a widespread unconformity. Following this, the final phase of drift evolution established the contourite depositional system (CDS) architecture we see today. There is a significant climate control on this evolution of MOW and bottom-current activity. However, from the closure of the Atlantic–Mediterranean gateways in Spain and Morocco just over 6 Ma and the opening of the Gibraltar Gateway at 5.3 Ma, there has been an even stronger tectonic control on margin development, downslope sediment transport and contourite drift evolution. The Gulf of Cadiz is the world's premier contourite laboratory and thus presents an ideal testing ground for the contourite paradigm. Further study of these contourites will allow us to resolve outstanding issues related to depositional processes, drift budgets, and recognition of fossil contourites in the ancient record on shore. The expedition also verified an enormous quantity and extensive distribution of contourite sands that are clean and well sorted. These represent a relatively untapped and important exploration target for potential oil and gas reservoirs.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Copernicus GmbH
Date: 24-10-2023
Abstract: Abstract. Nick Shackleton's research on piston cores from the Iberian margin highlighted the importance of this region for providing high-fidelity records of millennial-scale climate variability, and for correlating climate events from the marine environment to polar ice cores and European terrestrial sequences. During the Integrated Ocean Drilling Program (IODP) Expedition 339, we sought to extend the Iberian margin sediment record by drilling with the D/V JOIDES Resolution. Five holes were cored at Site U1385 using the advanced piston corer (APC) system to a maximum depth of ~155.9 m below sea floor (m b.s.f.). Immediately after the expedition, cores from all holes were analyzed by core scanning X-ray fluorescence (XRF) at 1 cm spatial resolution. Ca/Ti data were used to accurately correlate from hole-to-hole and construct a composite spliced section, containing no gaps or disturbed intervals to 166.5 m composite depth (mcd). A low-resolution (20 cm s le spacing) oxygen isotope record confirms that Site U1385 contains a continuous record of hemipelagic sedimentation from the Holocene to 1.43 Ma (Marine Isotope Stage 46). The sediment profile at Site U1385 extends across the middle Pleistocene transition (MPT) with sedimentation rates averaging ~10 cm kyr−1. Strong precession cycles in colour and elemental XRF signals provide a powerful tool for developing an orbitally tuned reference timescale. Site U1385 is likely to become an important type section for marine–ice–terrestrial core correlations and the study of orbital- and millennial-scale climate variability.
Publisher: American Geophysical Union (AGU)
Date: 09-2020
DOI: 10.1029/2020GC009248
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: Springer Science and Business Media LLC
Date: 12-2018
Publisher: Elsevier BV
Date: 05-2011
Publisher: International Ocean Discovery Program
Date: 23-04-2020
Publisher: American Geophysical Union (AGU)
Date: 07-2018
DOI: 10.1029/2018PA003331
Publisher: American Association for the Advancement of Science (AAAS)
Date: 13-06-2014
Abstract: The trickle of water that began to flow from the Mediterranean Sea into the Atlantic Ocean after the opening of the Strait of Gibraltar turned into a veritable flood by the end of the Pliocene 2 to 3 million years ago. It then began to influence large-scale ocean circulation in earnest. Hernández-Molina et al. describe marine sediment cores collected by an ocean drilling expedition (see the Perspective by Filippelli). The results reveal a detailed history of the timing of Mediterranean outflow water activity and show how the addition of that warm saline water to the cooler less-salty waters of the Atlantic was related to climate changes, deep ocean circulation, and plate tectonics. Science , this issue p. 1244 see also p. 1228
Publisher: Elsevier BV
Date: 10-2015
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: Springer Science and Business Media LLC
Date: 22-01-2018
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: Elsevier BV
Date: 11-2019
Publisher: Springer Science and Business Media LLC
Date: 20-08-2018
Publisher: Elsevier BV
Date: 07-2018
Publisher: Springer Science and Business Media LLC
Date: 20-07-2016
DOI: 10.1038/SREP29838
Abstract: The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Mal es yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment’s content of particulate organic matter. A weaker ‘proto-monsoon’ existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 23-04-2020
Publisher: Elsevier BV
Date: 03-2014
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 28-09-2018
Publisher: International Ocean Discovery Program
Date: 23-04-2020
Publisher: International Ocean Discovery Program
Date: 07-03-2016
Publisher: Springer Science and Business Media LLC
Date: 26-03-2018
Publisher: Elsevier BV
Date: 09-2019
Location: United States of America
No related grants have been discovered for Carlos Alvarez Zarikian.