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Cotillon P., Rigolot P., Coustillas F., Gaillard C., Laurin B., Liu J.D., Pannetier W., Pascal A. & Rio M. 1989. Pentes et bassins au large de la Nouvelle Calédonie (Sud-Ouest Pacifique). morphologie, environnements biosédimentaires, sédimentation. Oceanologica Acta 12(2): 131-140
Abstract [+]
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Submarine slopes and basins off New-Caledonia (South-Western Pacifie); morphology, biosedimentary environments, sedimentation During the Biocal deep-sea cruise off New-Caledonia, fauna and sediments were sampled and Seabeam maps were drawn. The first geological results are as follows: - block-faulting determines the morphology of the slopes, their erosion and the transport of sediments along them towards the Loyalty basin plain; - erosion is predominant in the studied areas of the western Caledonian slopes and along the slopes off Lifou island where the canyons are broad and scattered, whereas in front of the "passe de Thio", through the reefal barrier, a relatively high detritic influx transits through several narrow canyons; - the Loyalty basin has been explored along the Thio-Lifou transect; it exhibits a flat bottom and is fed mainly from the eastern Caledonian slopes by calcareous and argilaceous turbidites, which spread eastward over nearly 50 km and interfinger with hemipelagites; - the sediments are constituted by 5 distinct components: 15 to 50% of detritics from New-Caledonia (mainly clay minerais, iron oxydes and silicate minerais); 15 to 25% bioclastic silts and sands derived from the reefal ring and from the lagoon; mixed bioclasts ( 1 to 20%) furnished by benthonic communities living on the slopes and in the basin; planktonic debris (30 to 75%) with a dominant fraction composed of foraminifers and pteropods; and volcanic debris (0,5 to 10%). A sedimentation rate of about 6cm/1000 years (between 16000 and 5000 years B.P.)has been estimated from the explored sector of the Loyalty basin.
Accessible surveys cited (1) [+]
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Cotillon P., Rigolot P., Coustillas F., Gaillard C., Laurin B., Liu J.D., Pannetier W., Pascal A. & Rio M. 1990. Pentes et bassins au lare de la Nouvelle-Calédonie (Sud-Ouest Pacific) morphologie, environnements biosédimentaires, sédimentation. Oceanologica Acta 12(2): 131-140
Abstract [+]
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Submarine slopes and basins off New-Caledonia (South-Western Pacifie); morphology, biosedimentary environments, sedimentation During the Biocal deep-sea cruise off New-Caledonia, fauna and sediments were sampled and Seabeam maps were drawn. The first geological results are as follows: - block-faulting determines the morphology of the slopes, their erosion and the transport of sediments along them towards the Loyalty basin plain; - erosion is predominant in the studied areas of the western Caledonian slopes and along the slopes off Lifou island where the canyons are broad and scattered, whereas in front of the "passe de Thio", through the reefal barrier, a relatively high detritic influx transits through several narrow canyons; - the Loyalty basin has been explored along the Thio-Lifou transect; it exhibits a flat bottom and is fed mainly from the eastern Caledonian slopes by calcareous and argilaceous turbidites, which spread eastward over nearly 50 km and interfinger with hemipelagites; - the sediments are constituted by 5 distinct components: 15 to 50% of detritics from New-Caledonia (mainly clay minerais, iron oxydes and silicate minerais); 15 to 25% bioclastic silts and sands derived from the reefal ring and from the lagoon; mixed bioclasts ( 1 to 20%) furnished by benthonic communities living on the slopes and in the basin; planktonic debris (30 to 75%) with a dominant fraction composed of foraminifers and pteropods; and volcanic debris (0,5 to 10%). A sedimentation rate of about 6cm/1000 years (between 16000 and 5000 years B.P.) has been estimated from the explored sector of the Loyalty basin. Oceanologica Acta, 1989, 11, 2, 131-140.
Accessible surveys cited (1) [+]
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Pascal A., Rio M. & Vanney J.R. 1992. Les surfaces durcies des pentes bathyales de Nouvelle-Calédonie (Pacifique du SW). Morphologies et diagenèse. Bulletin de la société géologique de France 163(3): 271-280
Accessible surveys cited (3) [+]
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Pascal F., Rio M. & Pascal A. 1991. LES SEDIMENTS ACTUELS ET RECENTS DANS LE BASSIN DES LOYAUTE, L'environnement carbonaté bathyal en Nouvelle-Calédonie (Programme Envimarges). 15. Lambert B. & Roux M. (eds):75-85
Abstract [+]
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Les campagnes BIOCAL et BIOGEOCAL ont permis d'effectuer de nombreux prélèvements de sédiments récents dans le bassin des Loyauté à l'aide d'un carottier Usnel (KG) et d'un carottier Kullenberg (KK) (Fig. 1). La plupart d'entre eux se situe en bas des pentes et au centre du bassin. La partie haute des pentes a été rarement échantillonnée, mais en revanche, a fait l’objet d'observations directes lors de la campagne CALSUB (cf. Rio et al., ce volume). Au SW, le bassin est bordé par un récif barrière discontinu isolant un lagon relativement profond, tandis qu'au NE, l'atoll soulevé de Lifou ne possède que des récifs frangeants et un étroit palier littoral avant l'amorce du talus très pentu (cf. Roux, ce volume). Les résultats de la campagne BIOCAL (Cotillon et al., 1989b) ont indiqué que la sédimentation récente depuis 30.000 ans est constituée de boues hémipélagiques fines interrompues par des niveaux bioclastiques resédimentés. Nous présentons ici une analyse plus complète de la distribution des composants carbonatés dans les sédiments profonds, afin d'en cerner les différentes origines et d'apporter des informations supplémentaires sur la dynamique sédimentaire.
Accessible surveys cited (3) [+]
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