GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Document type
Keywords
Publisher
Language
Years
  • 1
    In: Quaternary research, Cambridge : Cambridge University Press, 1970, 73(2010), 2, Seite 385-392, 1096-0287
    In: volume:73
    In: year:2010
    In: number:2
    In: pages:385-392
    Description / Table of Contents: The relationship of sea-level changes and short-term climatic changes with turbidite deposition is poorly documented, although the mechanisms of gravity-driven sediment transport in submarine canyons during sea-level changes have been reported from many regions. This study focuses on the activity of the Dakar Canyon off southern Senegal in response to major glacial/interglacial sea-level shifts and variability in the NW-African continental climate. The sedimentary record from the canyon allows us to determine the timing of turbidite events and, on the basis of XRF-scanning element data, we have identified the climate signal at a sub-millennial time scale from the surrounding hemipelagic sediments. Over the late Quaternary the highest frequency in turbidite activity in the Dakar Canyon is confined to major climatic terminations when remobilisation of sediments from the shelf was triggered by the eustatic sea-level rise. However, episodic turbidite events coincide with the timing of Heinrich events in the North Atlantic. During these times continental climate has changed rapidly, with evidence for higher dust supply over NW Africa which has fed turbidity currents. Increased aridity and enhanced wind strength in the southern SaharanSahelian zone may have provided a source for this dust.
    Type of Medium: Online Resource
    Pages: graph. Darst
    ISSN: 1096-0287
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2019-09-23
    Description: The submarine Dakar Canyon incises the continental margin at the transition of the hyperarid Sahara to the semiarid Sahel Zone, and acts as an effective pathway for gravity-driven sediment transport. Four gravity cores recovered directly from the canyon axis were investigated in order to reconstruct the sedimentation processes in the Dakar Canyon during the Late Quaternary. In addition, a hemipelagic record from the northern levee of the canyon was analysed for monitoring background sediment supply, which is dominated by dust input in the area. Coarse terrigenous silt size data and high Ti/Ca ratios reflect overall increased higher dust supply during the last two peak glacials. During these times wide-extensive sand sea covered the exposed shelf almost completely. However, in interglacial periods wind stress diminished considerably and only minor amounts of dust were supplied to the outer shelf and continental slope. Two major periods of turbidite depositions are recorded in intervals from final glacial sea level lowstands to early deglacial sea level rise of the last two glacial/interglacial cycles (i.e. between 141 and 131 kyr BP and from 23.2 to 14.2 kyr BP). These turbidite deposits consist of sandy to silty sediments. Detailed grain size analyses were used to reconstruct the sedimentary characteristics and flow processes of these turbidity currents. A much higher frequency in turbidite activity occur around 135 kyr BP in contrast to the second interval around 18 kyr BP, suggesting a higher sediment budget in the source area. Based on the sedimentological investigation of the turbidites we provide a schematic model for the sedimentation processes in the Dakar Canyon.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2016-09-19
    Description: The relationship of sea-level changes and short-term climatic changes with turbidite deposition is poorly documented, although the mechanisms of gravity-driven sediment transport in submarine canyons during sea-level changes have been reported from many regions. This study focuses on the activity of the Dakar Canyon off southern Senegal in response to major glacial/interglacial sea-level shifts and variability in the NW-African continental climate. The sedimentary record from the canyon allows us to determine the timing of turbidite events and, on the basis of XRF-scanning element data, we have identified the climate signal at a sub-millennial time scale from the surrounding hemipelagic sediments. Over the late Quaternary the highest frequency in turbidite activity in the Dakar Canyon is confined to major climatic terminations when remobilisation of sediments from the shelf was triggered by the eustatic sea-level rise. However, episodic turbidite events coincide with the timing of Heinrich events in the North Atlantic. During these times continental climate has changed rapidly, with evidence for higher dust supply over NW Africa which has fed turbidity currents. Increased aridity and enhanced wind strength in the southern Saharan–Sahelian zone may have provided a source for this dust.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-09-23
    Type: Conference or Workshop Item , NonPeerReviewed
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    facet.materialart.
    Unknown
    PANGAEA
    In:  Supplement to: Pierau, Roberto; Hanebuth, Till J J; Krastel, Sebastian; Henrich, Rüdiger (2010): Late Quaternary climatic events and sea-level changes recorded by turbidite activity, Dakar Canyon, NW Africa. Quaternary Research, 73(2), 385-392, https://doi.org/10.1016/j.yqres.2009.07.010
    Publication Date: 2023-05-12
    Description: The relationship of sea-level changes and short-term climatic changes with turbidite deposition is poorly documented, although the mechanisms of gravity-driven sediment transport in submarine canyons during sea-level changes have been reported from many regions. This study focuses on the activity of the Dakar Canyon off southern Senegal in response to major glacial/interglacial sea-level shifts and variability in the NW-African continental climate. The sedimentary record from the canyon allows us to determine the timing of turbidite events and, on the basis of XRF-scanning element data, we have identified the climate signal at a sub-millennial time scale from the surrounding hemipelagic sediments. Over the late Quaternary the highest frequency in turbidite activity in the Dakar Canyon is confined to major climatic terminations when remobilisation of sediments from the shelf was triggered by the eustatic sea-level rise. However, episodic turbidite events coincide with the timing of Heinrich events in the North Atlantic. During these times continental climate has changed rapidly, with evidence for higher dust supply over NW Africa which has fed turbidity currents. Increased aridity and enhanced wind strength in the southern Saharan-Sahelian zone may have provided a source for this dust.
    Keywords: Center for Marine Environmental Sciences; MARUM
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2023-06-27
    Keywords: 349; 352; 353; AGE; Center for Marine Environmental Sciences; Event label; GeoB9612-3; GeoB9614-1; GeoB9615-1; Gravity corer (Kiel type); Lithologic unit/sequence; M65/2; MARUM; Meteor (1986); off NW Africa; SL; Thickness
    Type: Dataset
    Format: text/tab-separated-values, 100 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2023-06-27
    Keywords: 349; Age, 14C AMS; Age, 14C milieu/reservoir corrected (-400 yr); Age, dated; Age, dated, range, minimum; Age, dated standard deviation; Age, maximum/old; Age, minimum/young; Calendar age; Center for Marine Environmental Sciences; DEPTH, sediment/rock; GeoB9612-3; Gravity corer (Kiel type); M65/2; MARUM; Meteor (1986); off NW Africa; Sample ID; SL
    Type: Dataset
    Format: text/tab-separated-values, 23 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2023-06-27
    Keywords: Age, 14C AMS; Age, dated; Age, dated material; Age, dated standard deviation; Calendar age; Calendar age, standard deviation; Carbon mass; Corrected; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Event label; GC; Gravity corer; Lake Fryxell, East Antarctica; Lz1021-1; Lz1021-2; Lz1021-3; Lz1021-4; Lz1021-5; Lz1021-6; Lz1021-7; PC; Piston corer; Sample code/label; Sample mass; Sampling/drilling in lake; TaylorValley2002; δ13C
    Type: Dataset
    Format: text/tab-separated-values, 321 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2023-06-27
    Keywords: AGE; Amphibole/standard ratio; Carbon, inorganic, total; Carbon, organic, total; Carbon, organic total/Sulfur, total, ratio; Density; DEPTH, sediment/rock; Feldspar/standard ratio; Lake Fryxell, East Antarctica; Lz1021; Magnetic susceptibility, volume; Nitrogen, total; PC; Piston corer; Pyroxene/standard ratio; Quartz/standard ratio; Sampling/drilling in lake; Sand; Silt; Size fraction 〈 0.002 mm, clay; Size fraction 〉 2 mm, gravel; Sulfur, total; TaylorValley2002; Volcanic glass; Water content, wet mass
    Type: Dataset
    Format: text/tab-separated-values, 3255 data points
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    PANGAEA
    In:  Supplement to: Wagner, Bernd; Melles, Martin; Doran, Peter T; Kenig, Fabien; Forman, Steven L; Pierau, Roberto; Allen, Phillip (2006): Glacial and postglacial sedimentation in the Fryxell basin, Taylor Valley, southern Victoria Land, Antarctica. Palaeogeography, Palaeoclimatology, Palaeoecology, 241, 320-337, https://doi.org/10.1016/j.palaeo.2006.04.003
    Publication Date: 2023-10-28
    Description: A 9.14 m long sediment sequence was recovered from Lake Fryxell, Taylor Valley, southern Victoria Land, Antarctica, and investigated for its chronology and sedimentological, mineralogical, and biogeochemical changes. The basal part of the sequence is dominated by coarse clastic matter, i.e., mainly sand. The sediment composition suggests that a lake existed in Fryxell basin during the Middle Weichselian by ca. 48,000 cal. year BP. After a short period of lake-level lowstand ca. 43,000 cal. year BP, lower Taylor Valley became occupied by the proglacial Lake Washburn, which was at least partly supplied by meltwater and sediments from the Ross Ice Sheet that was advanced to the mouth of Taylor Valley. Evaporation of Lake Washburn to lower levels started during the Last Glacial Maximum at ca. 22,000 cal. year BP, long before the Ross Ice Sheet retreated significantly. Lake-level lowering was discontinuous with a series of high and low stands. From ca. 4000 cal. year BP environmental conditions were similar to those of today and lower Fryxell basin was occupied by a small lake. This lake evaporated to a saline or hypersaline pond between ca. 2500 and 1000 cal. year BP and refilled subsequently.
    Keywords: GC; Gravity corer; Lake Fryxell, East Antarctica; Lz1021; Lz1021-1; Lz1021-2; Lz1021-3; Lz1021-4; Lz1021-5; Lz1021-6; Lz1021-7; PC; Piston corer; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Sampling/drilling in lake; SPP1158; TaylorValley2002
    Type: Dataset
    Format: application/zip, 2 datasets
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...