Fiche participant :
Nom : Cotillon
Prénom : Pierre
Liste des participations aux campagnes accessibles [+] [-]
- BIOCAL
- Leg 1 (Fri Aug 09 00:00:00 CEST 1985 - Sun Aug 18 00:00:00 CEST 1985)
- Carottage (Géologue - Structures sédimentaires, Université Claude Bernard Lyon 1)
- Leg 2 (Wed Aug 28 00:00:00 CEST 1985 - Mon Sep 09 00:00:00 CEST 1985)
- Carottage (Géologue - Structures sédimentaires, Université Claude Bernard Lyon 1)
- BIOGEOCAL
- Leg 1 (Tue Apr 07 00:00:00 CEST 1987 - Tue Apr 21 00:00:00 CEST 1987)
- Chef de mission (Géologue - Structures sédimentaires, Université Claude Bernard Lyon 1)
- Leg 2 (Sat Apr 25 00:00:00 CEST 1987 - Wed May 06 00:00:00 CEST 1987)
- Chef de mission (Géologue - Structures sédimentaires, Université Claude Bernard Lyon 1)
Bibliographie (9) [+] [-]
Exporter les bibliographies
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Cotillon P., Gaillard C., Evin J. & Liu J.D. 1989. Evolution du taux de sédimentation au cours des derniers 30 000 ans aux abords de la Nouvelle-Calédonie (SW Pacifique) : résultats de datations au radiocarbone et par la courbe de l'oxygène 18. Bulletin de la société géologique de France V(4): 881-884
Résumé [+] [-]The following results are deduced from radiocarbon and oxygen 18 curve datings obtained in Quaternary hemipelagic deposits cored off SW and SE slopes surrounding New-Caledonia: _ the radiometric age of total sediment (periplatform ooze + calcareous planctonic remains) exceeds that derived from the 8(18)0 curve yielded by Orbulina universa; _the rate of sedimentation strongly decreases, principally off southwestern coasts, during the last 16,000 years. This is a probable consequence of the screen-effect of the reefal Quaternary belt, enhanced by the Flandrian transgression.
Campagnes accessibles citées (2) [+] [-] -
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
Résumé [+] [-]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.
Campagnes accessibles citées (1) [+] [-] -
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
Résumé [+] [-]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.
Campagnes accessibles citées (1) [+] [-] -
Cotillon P., Pannetier W. & Ferry S. 1991. Originalité des pentes néo-calédoniennes. Comparaison avec d'autres marges actuelles et fossiles. Documents et Travaux de l'IGAL 15: 93-105
Campagnes accessibles citées (3) [+] [-] -
Cotillon P., Liu J.D. & Pannetier W. 1992. Dynamique de la sédimentation quaternaire sur les pentes et dans les bassins au large de la Nouvelle-Calédonie (SW Pacifique). Comparaison avec d'autres systèmes de dépôts carbonatés actuels et anciens. Bulletin de la société géologique de France 163(3): 241-254
Résumé [+] [-]Basins and their edges were surveyed during crui ses of ENVIMARGES program in the vicinity of New Caledonia. Quaternary deposits include a major carbonate fraction mainly issued from plankton and reef systems surrounding the lands (New Caledonia and Loyalty islands) and a rather argillaceous terrigenous fraction derived from New-Caledonia. SW of New-Caledonia and on both sides of Lifou islands, the submarine slopes are concave and intensely eroded. At the foot of them and beyond, the sedimentation is weak and carbonate-rich. NE of New-Caledonia, the slope is straight and also actively eroded; carbonate and terrigenous material by-pass along it ; slumps and debris-flows accumulate down the slope and turbidites spread over the Loyalty basin. The major features of sedimentation are then splitted between two poles defined by platform and hinterland characteristics: a carbonate pole, comparable with that of the Bahamas, and a mixed carbonate and siliciclastic pole from what the originality of this depositional area is derived and which is determining the fastest sedimentation. The whole system is also dependent on climatic and eustatic Quaternary fluctuations. Interglacial periods are marked by reef growth and carbonate enriched deposits, particularly with aragonite. Reversely, carbonate impoverishments and biological silica enrichments are observed in sediments during glacial periods. The system is also controlled by tectonics but through still undetermined degree and process . The most recent described "Carbonate platform-slope-basin" systems depend on an exclusive carbonate pole. However slope erosions so clear and important as off New-Caledonia are not quoted.To some extent, the behaviour of Loyalty basin during the Quaternary can help in the comprehension of ancient basins. However, a comparison with the Loyalty basin shows the difficulty for restituting palaeomorphologies. In addition , it may be hazardous to use directly observations on a present basin for a better knowledge of ancient sedimentary systems because of scale changes concerning time and the network of observations.
Campagnes accessibles citées (2) [+] [-] -
Gaillard C., Cotillon P. & Evin J. 1989. Un cas de mise en place de turbidites récentes dans des boues hémipeIagiques. Résultats obtenus par datation au radiocarbone de sédiments superficiels dans Ie bassin des Loyauté (Nile Calédonie). Bulletin de la société géologique de France V(4): 875-879
Campagnes accessibles citées (2) [+] [-] -
Liu J.D. & Cotillon P. 1989. Present and recent sedimentation in the Loyalty basin along the Thio-Lifou profile (New Caledonia, Southwest Pacific). Marine Geology 87: 207-226
Résumé [+] [-]The Loyalty Basin, northeast of New Caledonia, is about 100 km wide and 2350 m deep in the transect between Thio (New Caledonia) and the island of Lifou. It is bounded to the southwest by New Caledonia and its surrounding barrier reef and to the northeast by the barrier reef of the Loyalty Ridge. Lifou Island, a raised atoll, is an emerged part of the Loyalty Ridge. The sediments cored in the Loyalty Basin during the BIOCAL mission in 1985 are bioturbated and composed of an alternation of turbidites and hemipelagites. The hemipelagites are brown -yellowish muddy oozes to calcareous muds; the turbidites are composed of sandy and silty oozes capped transitionally with muddy oozes. The hemipelagite and the T, division of the Bouma sequence have different characteristics but are not located in the core. However, they can be distinguished by carbonate composition and grain size. All the sediments originate from five sources: (1) New Caledonia (quartz, mud and heavy minerals), (2) the barrier reef (fragments of algae, madreporarian corals, foraminifera and mud of the periplatform, (3) plankton (foraminifera, coccoliths and pteropoda), (4) the bathyal community and (5) pyroclastic fragments. Turbidites, distributed in cores between Thio and Lifou, constitute a low-profile submarine fan fed by the main canyons of the slope opposite the Thio Pass. The fan developed from a rim of slumps and mud flows located near the base of the slope. The fan extends 50 km toward the northeast as far as the tectonic Levi Ridge. The hemipelagites are predominant beyond this ridge. The modern sedimentation rate is 60 m/Ma on the proximal fan. It is 4- 6 times less than the average sedimentation rate calculated for the period since the origin of the basin in the late Eocene.
Campagnes accessibles citées (1) [+] [-] -
Lévi C. & Cotillon P. 1989. CAMPAGNE BIOCAL : ENVIRONNEMENT BATHYAL ACTUEL ET RECENT AUX ABORDS DE LA NOUVELLE CALEDONIE,, in Colloque Tour du Monde du Jean Charcot, Paris, IFREMER - INSU - ORSTOM: 9 pp.
Campagnes accessibles citées (1) [+] [-] -
Pannetier W., Cotillon P. & Lambert B. 1991. Contrôle climato-eustatique de la sedimentation quaternaire dans les bassins, L'environnement carbonaté bathyal en Nouvelle-Calédonie (Programme Envimarges). 15. L'environnement carbonaté bathyal en Nouvelle-Calédonie (Programme Envimarges).:87-92
Résumé [+] [-]Les fluctuations conjointes du niveau marin de la mer et du développement récifal sont enregistrées par la sédimentation quaternàire dans les domaines de périplate-forme et de bassin. Telle est la conclusion d'études menées surtout aux Bahamas et dans leurs environs immédiats (Boardman et al., 1986 ; Kier et Pilkey, 1971 ; Droxler et al., 1988). Dans cette région les sédiments profonds contiennent 70 à 90% de carbonates provenant des plates-formes carbonatées et de leurs récifs (Boardman et Neumann, 1984), les pourcentages dépendant du développement des bioconstructions soumises aux oscillations marines des périodes glaciaires et interglaciaires. En période froide et de bas niveau marin, le récif émerge et subit une altération météoritique, ce qui se traduit par une -réduction du flux détritique carbonaté dans les bassins, et, par conséquent, par de faibles teneurs relatives en carbonates totaux et en aragonite. En période chaude, la remontée du niveau de la mer favorise la croissance du récif qui devient alors une source importante pour le détritisme carbonaté. On observe donc un relèvement des pourcentages en carbonates totaux et en aragonite dans les sédiments. Ce mécanisme a été retrouvé dans les bassins des Loyauté et de Nouvelle-Calédonie, mais quelque peu modulé par le contexte mixte, carbonaté et silicoclastique, de la sédimentation, différant sensiblement de celui, purement carbonaté, des Bahamas. La carotte 21, prélevée au pied de la pente SW de la Nouvelle-Calédonie (Fig. 1), a permis d'établir des corrélations entre la succession récifale quaternaire traversée par forage au Sud-Ouest de la Nouvelle-Calédonie (Coudray, 1976) et l'évolution verticale de divers composants sédimentaires. Ce principe de corrélation a été ensuite étendu aux forages du bassin des Loyauté.
Campagnes accessibles citées (1) [+] [-]