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| Seo, Inah; Lee, Yuri; Lee, Yong Il; Yoo, Chan Min; Hyeong, Kiseong. |
| This paper investigates paleoceanographic changes at a central equatorial Pacific site (6 degrees 40N, 177 degrees 28W) since the last glacial maximum using planktic foraminifera assemblages, together with the oxygen isotope (O-18) and Mg/Ca compositions of three species (Globigerinoides sacculifer, Pulleniatina obliquiloculata, and Globorotalia tumida) that dwell in the mixed layer, upper thermocline, and lower thermocline, respectively. While the Mg/Ca-derived temperatures of the mixed layer and lower thermocline varied within a narrow range from 18 ka onward, the upper thermocline temperature increased by as much as 3 degrees C during the last deglaciation (18-12 ka) with a simultaneous decrease of O-18. These changes are best explained by an enhanced... |
| Tipo: Text |
Palavras-chave: Planktic foraminifera; Geochemistry; Micropaleontology; Paleoceanography; Intertropical Convergence Zone; Last deglaciation. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00496/60721/65271.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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| De Garidel-thoron, T; Beaufort, L; Linsley, Bk; Dannenmann, S. |
| The primary productivity dynamics of the last 200,000 years in the Sulu Sea was reconstructed using the abundance of the coccolithophore Florisphaera profunda in the IMAGES MD97-2141 core. We find that primary productivity was enhanced during glacial periods, which we suggest is due to a stronger East Asian winter monsoon. During the last 80 kyr, eight significant increases in primary productivity (PP) in the Sulu Sea are similar to East Asian winter monsoon changes recorded in Chinese loess. The PP maxima are not linked with Heinrich events (HE) in the North Atlantic, although four PP peaks are synchronous with HE. The PP oscillations have frequencies near those of the Dansgaard-Oeschger cycles in Northern Hemisphere ice records and indicate a... |
| Tipo: Text |
Palavras-chave: Micropaleontology; Pacific Ocean. |
| Ano: 2001 |
URL: https://archimer.ifremer.fr/doc/00221/33187/31809.pdf |
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| Andersson, C; Risebrobakken, B; Jansen, E; Dahl, So. |
| Late Holocene sea surface ocean conditions of the eastern Norwegian Sea (Voring Plateau) are inferred from planktic stable isotopes and planktic foraminiferal assemblage changes in cores JM97-948/2A and MD95-2011 (66.97degreesN, 7.64degreesE). Strong covariance between the planktic stable oxygen isotopic record and abundance changes of N. pachyderma (sin) show that major changes in surface ocean conditions are reflected both in the geochemical composition of the foraminiferal tests as well as in the composition of the foraminiferal fauna. Surface ocean conditions warmer than present were common during the past 3000 years. During the so-called Medieval Warm Period, surface conditions were highly variable with marked changes in sea surface temperature. The... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Stable isotope; Holocene; Micropaleontology. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33495/31954.pdf |
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| Chang, Yp; Chang, Cc; Wang, Lw; Chen, Mt; Wang, Ch; Yu, Ef. |
| A high-resolution (similar to 4 - 5cm/kyr) giant piston core record (MD962085) retrieved during an IMAGES II - NAUSICAA cruise from the continental slope of the southeast Atlantic Ocean reveal striking variations in planktonic foraminifer faunal abundances and sea-surface temperatures (SST) during the past 400,000 years. The location and high-quality sedimentary record of the core provide a good opportunity to assess changes in the intensity and position of the Benguela Current System and the Subtropical Convergence, two key features of the ocean-climate system in the south Atlantic. This record can be also used to evaluate the possible influence of Agulhas Current from the throughflow of the Indian Ocean into the South Atlantic. The planktonic foraminifer... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Late Quaternary; Micropaleontology; South Atlantic. |
| Ano: 1999 |
URL: https://archimer.ifremer.fr/doc/00239/35070/34563.pdf |
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| SILVA,WAGNER G.; ZERFASS,GEISE S.A.; SOUZA,PAULO A.; HELENES,JAVIER. |
| This paper presents the integration of micropaleontological (palynology and foraminifera) and isotopic (87Sr/86Sr) analysis of a selected interval from the well 2-TG-96-RS, drilled on the onshore portion of the Pelotas Basin, Rio Grande do Sul, Brazil. A total of eight samples of the section between 140.20 and 73.50 m in depth was selected for palynological analysis, revealing diversified and abundant palynomorph associations. Species of spores, pollen grains and dinoflagellate cysts are the most common palynomorphs found. Planktic and benthic calcareous foraminifera were recovered from the lowest two levels of the section (140.20 and 134.30 m). Based on the stratigraphic range of the species of dinoflagellate cysts and sporomorphs, a span age from Late... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Micropaleontology; Biostratigraphy; Neogene; Pelotas Basin. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000401565 |
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