Sedimentary architecture of a low-accumulation shelf since the Late Pleistocene (NW Iberia)

Lantzsch, Hendrik; Hanebuth, Till J J; Bender, Vera Barbara; Krastel, Sebastian

doi:10.1016/j.margeo.2008.12.008

Cited by 27 publications

(31 citation statements)

References 35 publications

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“…Reflecting the end of transgressive reworking on the shelf, the top of the sandy transgressive unit (U2) on the shelf dates to ca. 10 cal ka BP (Lantzsch et al 2009b(Lantzsch et al , 2010. Besides the subsequently decreased supply, the sortable silt data indicate decelerated slope currents from the early Holocene onwards, additionally leading to the disappearance of the~30 μm silt fraction.…”

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 92%

“…The higher frequency of storm tracks over NW Iberia after 4.5 cal ka BP have been interpreted from Ría de Muros sediments by Pena et al (2010), whereas a shift to less stormy conditions at 2.8 cal ka BP has been reported for a Galician outer shelf sediment record (González-Álvarez et al 2005). However, the latter is drawn from a sandy-to-muddy lithofacies change at 2.8 cal ka BP, which could also be interpreted in terms of a timetransgressive lateral expansion of the Galician mud belt (Lantzsch et al 2009b). Holocene sample and age tie point resolution of the present study is too low to clearly differentiate whether the additional terrigenous mud on the slope after ca.…”

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 97%

“…Lantzsch et al 2009a). The inner and outer shelf as well as the shelf break are covered with sandy, partly glauconitic sediments (Dias et al 2002;Lantzsch et al 2009b). The shelf break is generally reached at 160-180 m water depth.…”

Section: Physical Settingmentioning

confidence: 99%

“…1a) has been observed under modern conditions . On the shelf, glauconite-rich fine sands in the same area have been interpreted as an outer shelf palimpsest facies (Lantzsch et al 2009b). Both findings indicate active winnowing and resuspension processes-thus, an active shelf mud export in the area around 42°30′N.…”

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 99%

“…The ongoing sea-level rise (Peltier and Fairbanks 2006) would have caused strong reworking of the outer to mid-shelf sediments. During early deglacial sea-level rise (18-15 cal ka BP), immense reworking has been documented on the mid-shelf (Lantzsch et al 2009b(Lantzsch et al , 2010. The sand fraction would have been directly redeposited on the outer shelf, whereas silt and clay would have been exported by winnowing (Lantzsch et al 2010), producing LSRs of up to 37 cm/1,000 years (GeoB13071-1) on the slope.…”

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 99%

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Control of sediment supply, palaeoceanography and morphology on late Quaternary sediment dynamics at the Galician continental slope

et al. 2012

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Controls of sediment dynamics at the Galician continental slope (NW Iberia) during the past 30 ka were reconstructed from three new gravity cores (GeoB11035-1, 130206-1, 13071-1) based on sedimentological (e.g. sortable silt, IRD), micropalaeontological (e.g. coccoliths), geochemical (AMS 14 C, XRF) and geophysical (e.g. magnetic susceptibility) diagnostics. The data are consistent with existing regional knowledge that, during marine isotope stages 3-1, variations in detrital input, marine productivity and sea level were the essential drivers of sediment availability on the slope, whereas deep-water current velocities controlled sediment deposition: (1) the period prior to 30 cal ka BP is characterized by minor but systematic variations in various proxies which can be associated with D-O cycles; (2) between 30 and 18 cal ka BP, high detrital input and steady slope-parallel currents led to constant sedimentation; (3) from the LGM until 10 cal ka BP, the shelftransgressive sea-level rise increased the detrital particle flux; sedimentation was influenced by significantly enhanced deep-water circulation during the Bølling/Allerød, and subsequent slowing during the Younger Dryas; (4) an abrupt and lasting change to hemipelagic sedimentation at ca. 10 cal ka BP was probably due to Holocene warming and decelerated transgression; (5) after 5 cal ka BP, additional input of detrital material to the slope is plausibly linked to the evolution of fine-grained depocentres on the Galician shelf, this being the first report of this close shelfslope sedimentary linkage off NW Iberia. Furthermore, there is novel evidence of the nowadays strong outer shelf Iberian Poleward Current becoming established at about 15.5 cal ka BP. The data also demonstrate that small-scale morphologic features and local pathways of sediment export from the neighbouring shelf play an important role for sediment distribution on the NW Iberian slope, including a hitherto unknown sediment conduit off the Ría de Arousa. By implication, the impact of local morphology on alongand down-slope sediment dynamics is more complex than commonly considered, and deserves future attention.

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Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 92%

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 97%

Section: Physical Settingmentioning

confidence: 99%

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 99%

Section: Influence Of Local Morphology On Sedimentation Patternsmentioning

confidence: 99%

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Control of sediment supply, palaeoceanography and morphology on late Quaternary sediment dynamics at the Galician continental slope

et al. 2012

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The Iberian Atlantic Margin

Moura

Gomes

Horta

2017

Submerged Landscapes of the European Continental Shelf

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Evolution of the Galicia Interior Basin over the last 60 ka: sedimentary processes and palaeoceanographic implications

Mena

Francés

Pérez‐Arlucea

et al. 2018

J Quaternary Science

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The Galicia Interior Basin (GIB; NW Iberian Peninsula) is located near a critical transition between the subtropical (temperate) and subpolar (cold) gyres of the North Atlantic. It therefore witnesses oceanographic changes driven by global climatic events. This study reports on the recent (latest Pleistocene) sedimentary, palaeoceanographic and palaeoclimatic history of the basin. We integrated analysis of deep-sea sediment cores retrieved from an E-W transect across the GIB. The analysis indicated three types of sedimentary processes recording glacial (Marine Isotope Stage 2-4) and deglacial events: along-slope bottom currents (forming contourite deposits), pelagic and hemipelagic sedimentation, and gravitational dislocation. Variation in depositional patterns and sedimentation rates indicate distinctive transport (along-slope and down-slope) and depositional processes. These in turn reflect climatic and oceanographic drivers. We interpret changes in sea level from core evidence showing changes in sediment supply. The cores exhibited conspicuous sedimentary evidence of Heinrich events (HEs). The stratigraphic intervals associated with HEs showed significant lateral variation. We suggest that the lateral variation may result from the development of an oceanographic boundary between surface water masses with different temperature and salinity parameters or changes in surface currents which may have introduced relatively warmer water into the GIB during the last glacial period.

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Sedimentary architecture of a low-accumulation shelf since the Late Pleistocene (NW Iberia)

Cited by 27 publications

References 35 publications

Control of sediment supply, palaeoceanography and morphology on late Quaternary sediment dynamics at the Galician continental slope

Control of sediment supply, palaeoceanography and morphology on late Quaternary sediment dynamics at the Galician continental slope

The Iberian Atlantic Margin

Evolution of the Galicia Interior Basin over the last 60 ka: sedimentary processes and palaeoceanographic implications

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