Faugeres, Jean-Claude; Legigan, Philippe; Maillet, Noelle; Sarnthein, Michael; Stein, Ruediger (1989): Characteristics and distribution of Neogene turbidites at ODP Site 108-657 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.746616, Supplement to: Faugeres, J-C et al. (1989): Characteristics and distribution of Neogene turbidites at Site 657 (Leg 108, Cap Blanc continental rise, Northwest Africa): variations in turbidite source and continental climate. In: Ruddiman, W; Sarnthein, M; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 108, 329-348, https://doi.org/10.2973/odp.proc.sr.108.137.1989
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Published: 1989 (exact date unknown) • DOI registered: 2010-11-17
Abstract:
Numerous and variable silty-sandy siliciclastic turbidites were observed in Neogene pelagic sediments (late Miocene to Holocene) at Site 657: (1) thick-bedded, coarse-grained and thin-bedded, fine-grained turbidites; and (2) turbidites composed of eolian dune sand and shallow-water bioclasts or of fluvial-sand or mixed sandy component assemblages.
The stratigraphic distribution of these turbidites indicates five periods during which climatic conditions and material sources change. Turbidite occurrence prior to 6.2 Ma (late Miocene) is sparse; the deposits contain coarse and fine-grained turbidites with quartz grains of eolian or mixed origin suggesting the existence of arid conditions at about 8.5 and 6.5 Ma. A coarse-grained turbidite of fluvial origin, recording a humid climate, occurs at about 6.2 Ma. During the early Pliocene, turbidites are frequent (15/Ma); they contain only fine-grained sequences comprising material of mixed origin, which indicates a more humid climate perhaps. The late Pliocene starts with rare coarse-grained turbidites of wind-transported sand while the uppermost Pliocene deposits show a higher frequency of fine-grained sequences (10/0.7 Ma) composed mainly of fluvial material. During the early Pleistocene, similar high turbidite frequency was observed (20/1.3 Ma) but with a total lack of eolian supply. During the last 0.7 Ma, the frequency decreases and the sequences are characterized by highly variable sediment components that could be related to strong variations of climatic conditions.
The sedimentary characteristics of turbidites are mainly controlled by sediment source and climate. The frequency must be influenced by sea-level variations, by cyclic processes of climatic origin, and possibly by variations in the continental slope morphology. Clay mineral assemblages suggest a south Saharan source of terrigenous material during the late Miocene and the Pliocene and a northwest Saharan source during the Pleistocene.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Latitude: 21.331500 * Longitude: -20.948800
Date/Time Start: 1986-02-27T00:00:00 * Date/Time End: 1986-03-03T00:00:00
Event(s):
108-657 * Latitude: 21.331500 * Longitude: -20.948800 * Date/Time Start: 1986-02-27T00:00:00 * Date/Time End: 1986-03-03T00:00:00 * Elevation: -4232.0 m * Penetration: 344.3 m * Recovery: 261.1 m * Location: Canarias Sea * Campaign: Leg108 * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 38 cores; 344.3 m cored; 0 m drilled; 75.8% recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
3 datasets
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Datasets listed in this publication series
- Faugeres, J-C; Legigan, P; Maillet, N et al. (1989): (Table 2) Component assemblages in turbiditic sequences at ODP Site 108-657. https://doi.org/10.1594/PANGAEA.746613
- Faugeres, J-C; Legigan, P; Maillet, N et al. (1989): (Table 1) Structural and textural characteristics of the turbiditic sequence at ODP Site 108-657. https://doi.org/10.1594/PANGAEA.746610
- Faugeres, J-C; Legigan, P; Maillet, N et al. (1989): (Table 3) Clay minerals in turbidite sequences and associated pelagites at ODP Site 108-657A. https://doi.org/10.1594/PANGAEA.746614