Invited research articleSedimentary evolution of the Le Danois contourite drift systems (southern Bay of Biscay, NE Atlantic): A reconstruction of the Atlantic Mediterranean Water circulation since the Pliocene
Introduction
Contourite drifts are extensive sediment bodies built up through the action of alongslope bottom currents (Rebesco et al., 2008). When contour-following alongslope processes dominate over gravitational downslope processes along continental margins, Contourite Depositional Systems (CDS) may develop as various depositional (drifts) and erosive features (Hernández-Molina et al., 2008). In the NE Atlantic, circulation of the Mediterranean Outflow Water (MOW) leads to the generation of persistent bottom currents along the southwest European continental margin (van Aken, 2000b; Rogerson et al., 2012). In order to be able to distinguish pure thermohaline outflow (MOW) in the most proximal site to the source (the Strait of Gibraltar at the Gulf of Cádiz), the modified waters in the NE Atlantic are referred to as the Atlantic Mediterranean Water (AMW) (Rogerson et al., 2012; Flecker et al., 2015; Liu et al., 2019). Domination of Mediterranean water along the North Atlantic margins has resulted in the development of various contourite drifts and CDS (Collart et al., 2018; Hernández-Molina et al., 2011; Llave et al., 2006; Mena et al., 2018; Van Rooij et al., 2007, Van Rooij et al., 2010; Liu et al., 2019). These contourites display large variations in size, shape and vertical position along MOW/AMW pathways, thus provide valuable sedimentary records of the margin evolution and paleoceanography (Van Rooij et al., 2007; Ercilla et al., 2011; García et al., 2016; Hernández-Molina et al., 2016).
In the Gulf of Cádiz, the generation of the Cádiz CDS coincided with the first MOW enhanced stage during the early Pliocene (Llave et al., 2011; Roque et al., 2012; van der Schee et al., 2016). From the early Quaternary (~2 Ma) onwards, the Cádiz CDS experienced a major growth stage (Hernández-Molina et al., 2016). At the distal AMW site, sediment records from Goban Spur and Porcupine Seabight document extreme erosive events resulted from the AMW since the late Pliocene (Van Rooij et al., 2007; Huvenne et al., 2009; Thierens et al., 2013; Delivet et al., 2016). The ages of erosional events are difficult to reconstruct from sediment thicknesses and stacking pattern data due to erosional activities (Raddatz et al., 2011). Fast accumulation rates of the Porcupine CDS have only been recorded after the middle Pleistocene (0.725–0.65 Ma), which is more than ~1 My late compared to the Cádiz CDS (Huvenne et al., 2009; Hebbeln et al., 2016). There are still temporal gaps of MOW/AMW variability from proximal to distal sites. As such, a linkage between the Gulf of Cádiz and Porcupine Seabight is needed to document regional paleocirculation and associated sedimentary influences along the continental margins.
The Cantabrian continental margin (Fig. 1), positioned between the Gulf of Cádiz and Porcupine Seabight, lies in an understudied region with regard to AMW paleoceanography. Extensive submarine canyon systems interrupted alongslope transport of sediments, suggesting that downslope processes dominated (Weaver et al., 2000; Toucanne et al., 2008; Mulder et al., 2012). However, contourite depositional systems are identifiable among these canyon systems (Ercilla et al., 2008; Iglesias, 2009; Van Rooij et al., 2010; Liu et al., 2019), providing a unique opportunity to exam the AMW paleoceanography at an intermediate site. In the Le Danois Bank region, there are three water masses; 1) Eastern North Atlantic Central Water (ENACW), 2) AMW and 3) Labrador Sea Water (LSW) (Liu et al., 2019). Topographically constrained morphologies strongly intensify bottom currents, resulting in more frequent spatial variations of the related contourite features (González-Pola et al., 2012; Liu et al., 2019). A regional seismic stratigraphy of the Le Danois CDS has been addressed by Van Rooij et al. (2010), albeit on a relatively small set of seismic profiles. The CDS initiated during the early Pliocene and underwent a major growth stage from the late Pliocene onwards (Van Rooij et al., 2010). However, detailed insight of Pliocene-Quaternary sedimentary processes and evolution of the Le Danois CDS, as well as past circulation patterns of the AMW, are not well understood.
This work describes the seismic stratigraphy and sedimentary stacking patterns of the Le Danois CDS. The main objectives of this study are: (1) to document the temporal variability of contourite features; (2) to discuss sedimentary processes and evolution of drift systems; (3) to improve the understanding of past dynamics of intermediate water masses through the late Pliocene to the present day along the Cantabrian continental slope. The location of the Le Danois CDS is key for understanding past AMW variability between its proximal and distal sites. Newly acquired seismic data allows the identification of Le Danois contourite features in a higher lateral and temporal resolution.
Section snippets
Geological setting
The Le Danois Bank region, located at the Cantabrian continental margin, consists of an intraslope basin, the Le Danois Bank, the Lastres Canyon and the Asturias continental shelf (Figs. 1a and 2c). Contourite drifts and associated moats are present in the intraslope basin (Van Rooij et al., 2010; Liu et al., 2019). Among them, the Le Danois Drift is located between 790 and 1080 m water depth, while the Gijón Drift is located between 320 m and 1060 m water depth (Fig. 2c). The small Asturias
Methodology
This study is based on single channel sparker and multi-channel airgun reflection seismic data (Fig. 2a). High-resolution single channel seismic data were acquired using a 500 J energy SIG sparker (120 electrodes) during the R/V Belgica cruise ST1118a in 2011. Penetration of the acoustic signal is around 500 ms TWT. The dominant frequency is around 800 Hz and vertical resolution is about 1.5 m. A total of 27 sparker seismic lines, with a NNE-SSW (12 lines) and W-E to WNW-ESE (15 lines)
Seismic stratigraphic framework
Based on seismic interpretation of the sparker and airgun seismic profiles, six seismic units (U1–U6) bounded by major discontinuities (H1–H6) have been identified from old to young, respectively (Fig. 3, Table 1). The penetration of the sparker source (~500 ms TWT, while ~1500 ms TWT for airgun source) inhibits observation of the lowermost unit 1 (Fig. 4, Fig. 5). Unit 2 can only be recognized within the northern part of the intraslope basin (Fig. 3, Fig. 4), whereas both units could be
Chronostratigraphic framework
The chronostratigraphic framework in this study is established through the correlation of the seismic stratigraphy with limited regional borehole information (Cadenas and Fernández-Viejo, 2017). The tectonic and sedimentary evolution of the Cantabrian continental margin was described from seismic reflection data and borehole logs, which allowed the construction of a tentative chronostratigraphic framework (Ercilla et al., 2008; Iglesias, 2009; Van Rooij et al., 2010; Cadenas and
Conclusion
The Pliocene-Quaternary variability of contourite features and depositional processes of the Le Danois CDS illustrate past bottom-current circulation patterns along the Cantabrian continental margin. During the early Pliocene the AMW was very weak and the effective interaction of it along the Cantabrian continental margin initiated during the late Pliocene (3.5–3.0 Ma). During the early Quaternary (2.5–0.9 Ma), internal waves resulted from turbulent mixing of water masses and induced
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This study was carried out within the framework of a Chinese Scholarship Council “CSC Grant” (201506410062). This study built on achievements of project ESF Euromargins MOUNDFORCE, EC FP5 RTN EURODOM and EC FP6 HERMES 626 (GOCE-CT-2005-511234-1). The research cruises namely framed within the ECOMARG (REN2002-624 00916/MAR) and MARCONI (REN2001-1734 C03-01/M) projects. Shiptime RV Belgica was provided by BELSPO and RBINS–OD Nature. This study was conducted in collaboration with “The Drifters”
References (117)
- et al.
Seismic structure of the northern continental margin of Spain from ESCIN deep seismic profiles
Tectonophysics
(1996) - et al.
Oceanic heat pulses fueling moisture transport towards continental Europe across the mid-Pleistocene transition
Quat. Sci. Rev.
(2018) - et al.
Subduction and tectonics on the continental margin off northern Spain
Mar. Geol.
(1979) - et al.
A Pliocene mixed contourite–turbidite system offshore the Algarve Margin, Gulf of Cadiz: Seismic response, margin evolution and reservoir implications (Cadiz)
Marine and Petroleum Geology
(2013) - et al.
Sedimentary processes and cold-water coral mini-mounds at the Ferrol canyon head, NW Iberian margin
Prog. Oceanogr.
(2018) - et al.
Seismic geomorphological reconstructions of Plio-Pleistocene bottom current variability at Goban Spur
Mar. Geol.
(2016) - et al.
Mid- to late Cenozoic canyon development on the eastern margin of the Rockall Trough, offshore Ireland
Mar. Geol.
(2006) - et al.
Morphosedimentary features and recent depositional architectural model of the Cantabrian continental margin
Mar. Geol.
(2008) - et al.
Multi-process generated sediment waves on the Landes Plateau (Bay of Biscay, North Atlantic)
Mar. Geol.
(2002) - et al.
Chapter 14 Contourite Drifts: Nature, Evolution and Controls
Evolution of the Late Miocene Mediterranean–Atlantic gateways and their impact on regional and global environmental change
Earth-Sci. Rev.
Intensification of Northern Hemisphere glaciations in the circum Atlantic region (3.5–2.4 Ma) – ice-rafted detritus evidence
Palaeogeogr. Palaeoclimatol. Palaeoecol.
Erosive sub-circular depressions on the Guadalquivir Bank (Gulf of Cadiz): interaction between bottom current, mass-wasting and tectonic processes
Mar. Geol.
Circulation patterns at Le Danois Bank, an elongated shelf-adjacent seamount in the Bay of Biscay
Deep Sea Res. I Oceanogr. Res. Pap.
The early Pliocene re-colonisation of the deep Mediterranean Sea by benthic foraminifera and their pulsed late Pliocene–Middle Pleistocene decline
Mar. Micropaleontol.
Good neighbours shaped by vigorous currents: Cold-water coral mounds and contourites in the North Atlantic
Mar. Geol.
Chapter 19 Continental Slope Contourites
Evolution of the gulf of Cadiz margin and Southwest Portugal contourite depositional system: Tectonic, sedimentary and paleoceanographic implications from IODP expedition 339
Mar. Geol.
Foraminifer isotope study of the Pleistocene Labrador Sea, Northwest North Atlantic (IODP Sites 1302/03 and 1305), with emphasis on paleoceanographical differences between its “inner” and “outer” basins
Mar. Geol.
Middle Pleistocene cold stage climates in the Mediterranean: New evidence from the glacial record
Earth Planet. Sci. Lett.
Sediment dynamics and palaeo-environmental context at key stages in the Challenger cold-water coral mound formation: clues from sediment deposits at the mound base
Deep Sea Res. I Oceanogr. Res. Pap.
New insights into upper MOW variability over the last 150 kyr from IODP 339 Site U1386 in the Gulf of Cadiz
Mar. Geol.
Submarine channel levee shape and sediment waves from physical experiments
Sediment. Geol.
Late Pliocene variations of the Mediterranean outflow
Mar. Geol.
Chapter 24 palaeoceanographic significance of contourite drifts
Zooming into the Mediterranean outflow fossil moat during the 1.2–1.8millionyears period (Early-Pleistocene) - an approach by radiogenic and stable isotopes
Glob. Planet. Chang.
Distinguishing sediment waves from slope failure deposits: field examples, including the ‘Humboldt slide’, and modelling results
Mar. Geol.
High-resolution stratigraphy of the Mediterranean outflow contourite system in the Gulf of Cadiz during the late Pleistocene: the impact of Heinrich events
Mar. Geol.
Quaternary chronostratigraphic framework and sedimentary processes for the Gulf of Cadiz and Portuguese Contourite Depositional Systems derived from Natural Gamma Ray records
Mar. Geol.
Sediment drifts and erosional surfaces in the Central Mediterranean: seismic evidence of bottom-current activity
Sediment. Geol.
Review of the late Quaternary stratigraphy of the northern Gulf of Cadiz continental margin: New insights into controlling factors and global implications
Earth-Science Reviews
Present deep-submarine canyons activity in the Bay of Biscay (NE Atlantic)
Mar. Geol.
A revised Early Miocene age for the instigation of the Eirik Drift, offshore southern Greenland: evidence from high-resolution seismic reflection data
Mar. Geol.
Variability in form and growth of sediment waves on turbidite channel levees
Mar. Geol.
Internal waves, an under-explored source of turbulence events in the sedimentary record
Earth-Sci. Rev.
Paleoenvironmental reconstruction of Challenger Mound initiation in the Porcupine Seabight, NE Atlantic
Mar. Geol.
Chapter 1 contourite research: a field in full development
Morphobathymetric analysis of the large fine-grained sediment waves over the Gulf of Valencia continental slope (NW Mediterranean)
Geomorphology
Large sediment waves over the Gulf of Roses upper continental slope (NW Mediterranean)
Mar. Geol.
The opening of the Bay of Biscay – a review
Earth-Sci. Rev.
Pliocene and Quaternary depositional model of the Algarve margin contourite drifts (Gulf of Cadiz, SW Iberia): seismic architecture, tectonic control and paleoceanographic insights
Mar. Geol.
Particle fluxes and their drivers in the Avilés submarine canyon and adjacent slope, central Cantabrian margin, Bay of Biscay
Prog. Oceanogr.
Late Glacial to Holocene history of the Mediterranean Outflow. Evidence from benthic foraminiferal assemblages and stable isotopes at the Portuguese margin
Palaeogeogr. Palaeoclimatol. Palaeoecol.
Sedimentary and oceanographic responses to early Neogene compression on the NW European margin
Mar. Pet. Geol.
Interaction of alongslope and downslope processes in the Alentejo Margin (SW Iberia) – Implications on slope stability
Mar. Geol.
Cold-water coral carbonate mounds as unique palaeo-archives: the Plio-Pleistocene Challenger Mound record (NE Atlantic)
Quat. Sci. Rev.
Activity of the turbidite levees of the Celtic-Armorican margin (Bay of Biscay) during the last 30,000 years: imprints of the last European deglaciation and Heinrich events
Mar. Geol.
The hydrography of the mid-latitude Northeast Atlantic Ocean: I: the deep water masses
Deep Sea Res. I Oceanogr. Res. Pap.
The hydrography of the mid-latitude Northeast Atlantic Ocean: II: the intermediate water masses
Deep Sea Res. I Oceanogr. Res. Pap.
The celtic and Armorican margins — a new view
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