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Registros recuperados: 51 | |
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Regoli, Fabienne; De Garidel-thoron, Thibault; Tachikawa, Kazuyo; Jian, Zhiming; Ye, Liming; Droxler, Andre W.; Lenoir, Guillaume; Crucifix, Michel; Barbarin, Nicolas; Beaufort, Luc. |
The depth of equatorial Pacific thermocline is diagnostic of the main modes of tropical climates. Past estimates of Pacific thermocline dynamics have been reconstructed either for the Last Glacial Maximum or on longer timescales at low resolution. Here we document a new high-resolution set of reconstructed past sea surface and subsurface waters temperatures from the southwestern subequatorial Pacific, core MD05-2930, in the Gulf of Papua, over the last 800 ka. We used two morphotypes of Globigerinoides ruber known to live at different water depths to reconstruct past stratification. We estimated calcification temperature of each morphotypes by Mg/Ca paleothermometry. Our subequatorial Pacific thermocline paleotemperature record indicates a response of the... |
Tipo: Text |
Palavras-chave: Equatorial Pacific; Thermocline; Pleistocene. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00295/40572/39477.pdf |
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Benabdellouahed, Massinissa; Dugue, Olivier; Tessier, Bernadette; Thinon, Isabelle; Guennoc, Pol. |
New high-resolution seismic data complemented with bedrock samples allowed us to propose a revised geological map of the Bay of Seine and to better define the control by the geological substrate on the morphogenesis and evolution of the Seine River during Pleistocene times. The new data confirm previous works. The Bay of Seine can be divided into two geological parts: a Mesozoic monocline domain occupying most of the bay and a syncline domain, mostly Tertiary, in the north, at the transition with the Central English Channel area. The highlighting of Eocene synsedimentary deformations, marked by sliding blocks in the syncline domain, is one of the most original inputs of this new study in the Bay of Seine that underlines the significant role of the... |
Tipo: Text |
Palavras-chave: Pléistocène; Normandie; Baie de Seine; Paléo-Seine; Sismique haute résolution; Incision; Nappes étagées; Nappes emboîtées; Contrôle tectonique; Normandy; Bay of Seine; Pleistocene; Paleo-Seine river; High-resolution seismic; Incision; Strath terraces; Fill terraces; Tectonic control. |
Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00167/27800/26000.pdf |
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Windler, Grace; Tierney, Jessica E.; Zhu, Jiang; Poulsen, Christopher J.. |
The Indo‐Pacific Warm Pool (IPWP) is home to the warmest sea surface temperatures in the world oceans, favoring strong tropospheric convection and heavy rainfall. The mechanisms controlling long‐term change in the region’s hydroclimate are still uncertain. Here, we present a 450,000‐year record of precipitation δD from southern Sumatra that records a consistent pattern of glacial isotopic enrichment and interglacial depletion. We synthesize existing paleo‐indicators of precipitation δD and δ18O in the IPWP and compare results with water isotope‐enabled climate simulations of the Last Glacial Maximum (LGM). The simulations show glacial isotopic enrichment over the eastern Indian Ocean extending into the southern IPWP and isotopic depletion over southeast... |
Tipo: Text |
Palavras-chave: Leaf wax; Water isotopes; Indo‐Pacific Warm Pool; Pleistocene; Proxy‐model comparison. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77060/78359.pdf |
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Railsback, L. Bruce; Brook, George A.; Liang, Fuyuan; Marais, Eugene; Cheng, Hai; Edwards, R. Lawrence. |
Stalagmite Orum-1 from a cave near Orumana in northwestern Namibia provides a multi-proxy record of regional drying with increasing global-scale warmth over the last 47 kyr, in a region with few long well-dated location specific paleoclimate records. Data from Stalagmite Orum-1 include carbon and oxygen stable isotope ratios, proportions of aragonite and calcite, pronouncedly differing petrographic fabrics, positions of layer-bounding surfaces, variation in layer-specific width, and changes in layer thickness, all of which combine to support change from wetter to drier conditions. Combined with fourteen U-Th ages, they suggest that climate was wetter in northwestern Namibia during globally cold MIS 3 than it is today, and with more grass than is present... |
Tipo: Text |
Palavras-chave: Namibia; Paleoclimate; Pleistocene; Holocene; Savanna; Stalagmite. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53213/54862.pdf |
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Beaudouin, Célia; Jouet, Gwenael; Suc, Jean-pierre; Berne, Serge; Escarguela, Gilles. |
The composition of the glacial vegetation of southern French plains has been a matter of debate for several decades. Vegetation is considered as steppic according to French and Spanish lacustrine pollen records whereas cave deposits suggest the presence of mesothermophilous trees through the Last Glacial Maximum. In our paper, we display new palynological records from marine sediments of the Gulf of Lions. They indicate the presence of Abies, Picea and deciduous Quercus in the Gulf of Lions, certainly located in the drainage basins of the Pyreneo-Languedocian rivers. These populations that were sensitive to short climatic events during Marine Isotopic Stage 2 could have been linked to northeastern Spanish and southeastern French relicts already evidenced... |
Tipo: Text |
Palavras-chave: Mediterranean Sea; Pleistocene; Climate; Vegetation. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2804.pdf |
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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 |
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Gallagher, Stephen J; Sagawa, Takuya; Henderson, Andrew C. G.; Saavedra-pellitero, Mariem; De Vleeschouwe, David; Black, Heather; Itaki, Takuya; Toucanne, Samuel; Bassetti, Maria-angela; Clemens, Steve; Anderson, William; Alvarez-zarikian, Carlos; Tada, Ryuji. |
The Japan Sea is directly influenced by the Asian monsoon, a system that transports moisture and heat across southeast Asia during the boreal summer, and is a major driver of the Earth's ocean‐atmospheric circulation. Foraminiferal and facies analyses of a 460 kyr record from IODP Expedition 346 Site U1427 in the Japan Sea reveal a record of nutrient flux and oxygenation that varied due to sea level and East Asian monsoon intensity. The East Asian summer monsoon (EASM) was most intense during MIS (Marine Isotope Stage) 5e, 7e, 9e and 11c when the Tsushima Warm Current flowed into an unrestricted well mixed normal salinity Japan Sea. Whereas East Asian winter monsoon (EAWM) conditions dominated MIS 2, 4, 6 and 8 when sea level minima restricted the Japan... |
Tipo: Text |
Palavras-chave: Tsushima Warm Current; Pleistocene; Holocene; Paleoceanography; East Asian summer monsoon; East Asian winter monsoon. |
Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00444/55591/57215.pdf |
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Sierro, Fj; Hodell, Da; Curtis, Jh; Flores, Ja; Reguera, I; Colmenero-hidalgo, E; Barcena, Ma; Grimalt, Jo; Cacho, I; Frigola, J; Canals, M. |
Down-core samples of planktonic and benthic foraminifera were analyzed for oxygen and carbon isotopes in International Marine Past Global Changes Study (IMAGES) core MD99-2343 in order to study the interactions between climate change in the Northern Hemisphere and the western Mediterranean thermohaline circulation at times of Heinrich events (HE). Our results confirm the antiphase correlation between enhanced North Atlantic Deep Water formation and low ventilation in the Mediterranean. However, this study reveals that this antiphase relationship in deepwater formation between the North Atlantic and Mediterranean was interrupted during times of HE when the injection of large volumes of water from melting icebergs reached the entrance to the Mediterranean.... |
Tipo: Text |
Palavras-chave: Climatic change; Heinrich events; Mediterranean Sea; Carbon and oxygen isotopes; Thermohaline circulation; Pleistocene. |
Ano: 2005 |
URL: https://archimer.ifremer.fr/doc/00232/34354/32759.pdf |
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Beu, A. G.. |
Fossil and living neustonic gastropods referred previously to Janthinidae are revised and included in Epitoniidae. Species recognized in Janthina Röding, 1798 (= Iodes, Iodina and Amethistina Mörch, 1860, Hartungia Bronn, 1861, Heligmope Tate, 1893, Violetta Iredale, 1929, Parajanthina Tomida & Itoigawa, 1982, and Kaneconcha Kaim, Tucholke & Warén, 2012) are J. typica (Bronn), Messinian–early Piacenzian (latest Miocene–early late Pliocene), c. 7–3.0 Ma (New Zealand, southern Australia, Japan, Morocco, dredged off Brazil, Madeira, Gran Canaria I., Selvagem Grande I., and Santa Maria I., Azores); J. krejcii sp. nov., Zanclean (early Pliocene), c. 4.8–4.3 Ma (Santa Maria I.); J. chavani (Ludbrook), late Piacenzian–early Calabrian (latest... |
Tipo: Text |
Palavras-chave: Biostratigraphy; Cosmopolitan; Fossil record; Neustonic gastropods; Pleistocene; Pliocene; Phylogeny. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00403/51476/52047.pdf |
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Lafosse, M.; Gorini, C.; Le Roy, P.; Alonso, B.; D'Acremont, E.; Ercilla, G.; Rabineau, Marina; Vazquez, J. T.; Rabaute, A.; Ammar, A.. |
In active basins, tectonics can segment the continental shelf and control its stratigraphic architecture and physiography. Segmentation can explain the local evolution and morphology of the continental shelf because of sea-level variations, local tectonic segmentation and hydrodynamic processes. Here we investigate the tectonically active Morocco continental margin (southern Alboran Sea) using high-resolution seismic profiles and multibeam bathymetric data. The active faults bounding the transtensive Nekor basin triggered the segmentation of the shelf into three sectors showing different subsidence rates: a western sector corresponding to an extensive fault relay, a central sector corresponding to the subsiding Al-Hoceima Bay and an eastern sector... |
Tipo: Text |
Palavras-chave: Seismic stratigraphy; Active tectonic; Pleistocene; Continental shelf; Swath bathymetry; Geomorphology; Western Mediterranean. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56232/57812.pdf |
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Schneider, A.; Panieri, G.; Lepland, A.; Consolaro, C.; Cremiere, A.; Forwick, M.; Johnson, J. E.; Plaza-faverola, A.; Sauer, S.; Knies, J.. |
Multiple proxies in the geological record offshore NW Svalbard track shallow subseafloor diagenesis and seafloor methane seepage during the Last Glacial Maximum (LGM) extent and the disintegration of the Svalbard Barents Sea Ice Sheet (SBIS). Vestnesa Ridge, located at 79°N and in 1200 m water depth, is one of the northernmost known active methane seep sites and is characterised by a subseafloor fluid flow system, numerous seafloor pockmarks and gas flares in the water column. In this study, we develop a Late Pleistocene and Holocene stratigraphic framework, use stable oxygen and carbon isotope signatures (δ18O, δ13C) of benthic and planktic foraminifera, the mineralogical and carbon isotope composition of methane-derived authigenic carbonate (MDAC) and... |
Tipo: Text |
Palavras-chave: Micropaleontology; Foraminifers; Stable isotopes; Methane seepage; Authigenic carbonate; Holocene; Pleistocene; Paleogeography; Deglaciation; Arctic Ocean. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00445/55652/60554.pdf |
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Boomer, Ian; Guichard, Francois; Lericolais, Gilles. |
During the last glacial phase the Black Sea basin was isolated from the world's oceans due to the lowering of global sea-levels. As sea-levels rose during the latest glacial and early Holocene period, the Black Sea was once again connected to the eastern Mediterranean via the Dardanelles-Marmara-Bosporus seaway. In recent years, trace element and stable isotope analyses of ostracod assemblages have yielded important details regarding the hydrological evolution of the Black Sea during these events. Despite this focus on the geochemical signatures of the ostracods, little if any attention has been paid to the taxonomic composition of the ostracod assemblages themselves and there are notably few publications on the sub-littoral fauna of this important water... |
Tipo: Text |
Palavras-chave: Ponto-Caspian; Black Sea; Ostracoda; Pleistocene; Holocene. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00025/13646/10887.pdf |
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Deptuck, M; Piper, D; Savoye, Bruno; Gervais, A. |
Sandy lobe deposits on submarine fans are sensitive recorders of the types of sediment gravity flows supplied to a basin and are economically important as hydrocarbon reservoirs. This study investigates the causes of variability in 20 lobes in small late Pleistocene submarine fans off East Corsica. These lobes were imaged using ultra-high resolution boomer seismic profiles (< 1 m vertical resolution) and sediment type was ground truthed using piston cores published in previous studies. Repeated crossings of the same depositional bodies were used to measure spatial changes in their dimensions and architecture. Most lobes increase abruptly down-slope to a peak thickness of 8 to 42 m, beyond which they show a progressive, typically more gradual, decrease... |
Tipo: Text |
Palavras-chave: Turbidites; Submarine lobes; Pleistocene; Dimensions; Compensation stacking; Architecture. |
Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4712.pdf |
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Hoek Ostende, L.W. van den. |
Having been described in 1904 by Dubois as a locality for fossil mammals, the Tegelen clay-pits are nowadays considered a ‘classical’ locality. It is the type locality of the Tiglian, a warm period of the Early Pleistocene or Late Pliocene. The pits are primarily known for their mammalian remains, but have also yielded seeds, pollen and freshwater snails. A century of collecting has resulted in extensive collections of large mammals in various museums, the most important of which are the Teylers Museum, Haarlem and the National Museum of Natural History Naturalis in Leiden. The latter museum also holds a large collection of microvertebrates, collected during campaigns in the 1970s. These campaigns showed that, in spite of the numerous fossils, the Tegelen... |
Tipo: Article / Letter to the editor |
Palavras-chave: Tegelen; Tiglian; Pleistocene; Fossil mammals; 38.20. |
Ano: 2004 |
URL: http://www.repository.naturalis.nl/record/215458 |
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Harper, D.A.T.; Donovan, S.K.. |
Pleistocene brachiopods are poorly known from the Antillean region, but are locally common in forereef deposits of Jamaica (lower Pleistocene Manchioneal Formation) and Barbados (Coral Rock). Of the four species known, two are new. Lacazella sp. cf. L. caribbeanensis Cooper, an encrusting thecideidean, is known from only three valves. Other species are terebratulides. Tichosina inconstanta sp. nov. is a large, ventribiconvex Tichosina species of elongate oval to tear-drop shaped outline, variably uniplicate with a pedicle foramen of moderate diameter. It differs from the similar Tichosina? bartletti (Dall) in having a larger pedicle foramen and a less-marked plication. Argyrotheca barrettiana (Davidson) is a medium to large, usually transverse Argyrotheca... |
Tipo: Article / Letter to the editor |
Palavras-chave: Brachiopoda; Pleistocene; Systematics; Jamaica; Barbados; Antilles; 42.72; 38.22. |
Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/314198 |
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Registros recuperados: 51 | |
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