|
|
|
| Registros recuperados: 11 | |
|
| |
|
|
| Kallel, N; Paterne, M; Duplessy, Jc; Vergnaudgrazzini, C; Pujol, C; Labeyrie, L; Arnold, M; Fontugne, M; Pierre, C. |
| Sea-surface temperature (SST) estimates for the last 10,000 years have been derived from foraminiferal fauna variations in ten cores from the Mediterranean Sea. For the eastern cores, modern analogs of fossil assemblages are found in the eastern Mediterranean Sea. In the Alboran and Tyrrhenian Seas, the bet analogs originate from modern fauna located either in the western Mediterranean Sea or in the North Atlantic Ocean. During the last sapropel event, centred at about 8,000 years B.P., SSTs were similar to present in the eastern basin, whereas they were colder than today by about 1.5 degrees C in the Alboran Sea and 2.5 degrees C in the Tyrrhenian Sea. Oxygen isotope measurements agree with ecological studies to show that Globigerina bulloides and... |
| Tipo: Text |
|
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20427/18094.pdf |
| |
|
| |
|
|
| Koc, N; Labeyrie, L; Manthe, S; Flower, Bp; Hodell, Da; Aksu, A. |
| Well-preserved diatoms are present in high sedimentation rate Pleistocene cores retrieved on ocean Drilling Program (ODP) Legs 151, 152, 162 and IMAGES cruises of RN Marion Dufresne from the North Atlantic. Investigation of the stratigraphic occurrence of diatom species shows that the youngest diatom event observed in the area is the last occurrence (LO) of Proboscia curvirostris (Jouse) Jordan and Priddle. P. curvirostris is a robust species that can easily be identified in the sediments, and therefore can be a practical biostratigraphic tool. We have mapped its: areal distribution, and found that it stretches from 40 degreesN to 80 degreesN in the North Atlantic. Further, we have correlated the LO P. curvirostris to the oxygen isotope records of six... |
| Tipo: Text |
Palavras-chave: Biostratigraphy; North Atlantic; Diatoms; Pleistocene; Paleoceanography; Isotope stratigraphy; Oxygen. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33210/31708.pdf |
| |
|
|
| Duplessy, Jc; Labeyrie, L; Juilletleclerc, A; Maitre, F; Duprat, J; Sarnthein, M. |
| We have developed a new method to reconstruct surface water salinity of the North Atlantic Ocean, based on a comparison between transfer function estimates of sea surface temperature and the oxygen isotope ratio of two common planktonic foraminiferal species, N. pachyderma (left coiling) and G. bulloides. We first used core-top analyses to demonstrate that, under modern conditions, the paleotemperatures determined from the isotopic composition of foraminiferal shells are linearly linked to the summer sea surface temperature only within a certain temperature range, characteristic of each species, which is termed the "optimum temperature range". We then used this information to derive an estimate of the isotopic composition and salinity of the North Atlantic... |
| Tipo: Text |
Palavras-chave: PALEO-OCEANOGRAPHY; PALEOCLIMATOLOGY; ISOTOPES; SALINITY; ATLANTIC OCEAN. |
| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00101/21261/18872.pdf |
| |
|
|
| Cortijo, E; Lehman, S; Keigwin, L; Chapman, M; Paillard, D; Labeyrie, L. |
| Eight deep-sea sediment cores from the North Atlantic Ocean ranging from 31 degrees to 72 degrees N are studied to reconstruct the meridional gradients in surface hydrographic conditions during the interval of minimum ice volume within the last interglacial period. Using benthic foraminiferal delta(18)O measurements and estimates of Sea Surface Temperature (SST) and Sea Surface Salinity (SSS), we show that summer SSTs and SSSs decreased gradually during the interval of minimum ice volume at high-latitude sites (52 degrees-72 degrees N) whereas they were stable or increased during the same time period at low-latitude sites (31 degrees-41 degrees N). This increase in meridional gradients of SSTs and SSSs may have been due to changes in the latitudinal... |
| Tipo: Text |
|
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00240/35076/34550.pdf |
| |
|
| |
|
| |
|
|
| Labeyrie, L. |
| The major purpose of the Estase cruise has been the coring of the high sedimentation rate sediment, along the continental slope of Japan (Estase I 03 09 84 to 17 09 84) and Philippine islands (Estase II 14 11 84 to 08 12 84), in the north-west Pacific Ocean. Two main scientific objectives were involved in this operation: High resolution paleoclimatology and paleoceanography of the eastern side of the Asian continent, by micropaleontological and isotopic studies of fossil foraminifera, and palynology of the wind and river transported pollens from the continent, and a detailed study of the paleovolcanism, by tephrochronology. |
| Tipo: Text |
|
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37915/35996.pdf |
| |
|
|
| Szeremeta, N; Bassinot, F; Balut, Y; Labeyrie, L; Pagel, M. |
| The depth-scale accuracy of marine sedimentary series collected by coring is of key importance for the precise calculation of sedimentation rates and fluxes. For three giant piston cores collected during the InterPole MD99-114/International Marine Past Global Changes Study (IMAGES) V cruise (MD99-2227, MD99-2246, and MD99-2251), the 3.5-kHz chirp profiles recorded on board are compared to synthetic seismograms computed from physical property logs measured on cores. In each case, the perfect match of main deep reflectors requires a significant upward shift of the water-sediment (W/S) interface in the synthetic seismograms with respect to the 3.5-kHz profiles. Since no drastic perturbation of the physical property logs is observed, this upward shift is... |
| Tipo: Text |
Palavras-chave: Correction of coring-induced sediment oversampling; Giant piston coring; IMAGES cores; North Atlantic. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00229/33978/32344.pdf |
| |
|
|
| Gayet, J; Carbonel, P; Duprat, J; Labeyrie, L; Faugeres, J-c; Gonthier, E; Moyes, J. |
| Biomarker data associated with isotopic curve partial differential super(18)O served to establish a stratigraphic scale and thereby a chronology of fluctuations in the circulation and sedimentation of the Kalimantan continental rise throughout the last climatic cycle. During the glacial maximum, period of low sea-level sediments were deposited by turbidity currents originating from Kalimantan. During deglaciation, during rise of the sea-level and more particularly in the Holocene, material issued from Kalimantan either contributed to the building of the Mahakam delta or was dispersed over the shelf. Sulawesi inputs, less abundant and mineralogically different from Kalimantan material, were observed onto the Kalimantan rise. During this same period,... |
| Tipo: Text |
|
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37898/35979.pdf |
| |
| Registros recuperados: 11 | |
|
|
|
