Home Itens selecionados Provedores de dados OAI Créditos Sobre Ajuda

			Busca avançada
	Provedor de dados ArchiMer (3) Autor Algeo, T. J. (1) Bassinot, Fc (1) Gehlen, M (1) Jia, Q. (1) Labeyrie, L (1) Levi, C (1) Li, T. (1) Melieres, F (1) Qin, B. (1) Sturm, Arne (1) Xiong, Z. (1) Mais... Palavra-chave Carbonate dissolution (3) Bottom water CO(3) (1) Calcite crystallinity (1) Carbon cycles (1) Carbonate chemistry (1) Coral reef hypothesis (1) Deep-water circulation (1) Electron spectroscopy and diffraction (1) Epibenthic delta13C (1) Foraminifers (1) Late Pleistocene (1) Mineral physics : X ray (1) Neutron (1) Ocean stratification (1) Paleoceanography (1) Planktonic foraminifer (1) Shell weight (1) Southern Ocean (1) Surface-water circulation (1) Mais... Tipo do documento Text (3) Ano 2018 (1) 2004 (2) País France (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Changes in ocean circulation and carbonate chemistry in the Australian sector of the Southern Ocean during the last 500,000 years ArchiMer Sturm, Arne. Stable oxygen and carbon isotope records and carbonate dissolution proxy records were used to reconstruct glacial/interglacial changes in ocean circulation, deep-water ventilation and carbonate chemistry in the Australian sector of the Southern Ocean for the last 500 kyr. Carbonate preservation records indicated a longitudinal gradient in Southern Ocean deep-water alkalinity at 110°E that persisted through glacial/interglacial stages. In contrast to previous studies suggesting the “Atlantic-type” carbonate preservation pattern in the entire Southern Ocean with enhanced carbonate preservation during interglacials and increased carbonate dissolution during glacials, this study, however, revealed that the reversed “Pacific-type” pattern of... Tipo: Text Palavras-chave: Late Pleistocene; Southern Ocean; Deep-water circulation; Carbonate chemistry; Epibenthic delta13C; Carbonate dissolution; Surface-water circulation. Ano: 2004 URL: https://archimer.ifremer.fr/doc/00499/61034/64441.pdf Crystallinity of foraminifera shells: A proxy to reconstruct past bottom water CO(3)(=) changes? ArchiMer Bassinot, Fc; Melieres, F; Gehlen, M; Levi, C; Labeyrie, L. The reconstruction of past changes in bottom water CO(3)(=) is central to evaluating competing oceanic scenarios that deal with long-term variations in atmospheric pCO(2). In search of a quantitative bottom water CO(3)(=) proxy, we analyzed the variations of calcite crystallinity of planktonic foraminifera Globigerinoides ruber shells picked from core top samples along three depth transects: Ontong Java Plateau and the northeast margin of Irian Jaya, in the western equatorial Pacific, and the Sierra Leone Rise, in the eastern tropical Atlantic. The strong empirical relationship between calcite crystallinity ( inferred from the full width at half maximum (FWHM) of calcite (104) X-ray diffraction peak) and bottom water saturation relative to calcite... Tipo: Text Palavras-chave: Bottom water CO(3); Calcite crystallinity; Carbonate dissolution; Foraminifers; Paleoceanography; Mineral physics : X ray; Neutron; Electron spectroscopy and diffraction. Ano: 2004 URL: https://archimer.ifremer.fr/doc/00226/33716/32138.pdf Deep-water Carbonate Ion Concentrations in the Western Tropical Pacific Since the Mid-Pleistocene: A Major Perturbation during the Mid-Brunhes ArchiMer Qin, B.; Li, T.; Xiong, Z.; Algeo, T. J.; Jia, Q.. We present a new deep‐water carbonate ion concentration ([CO32–]) record, reconstructed from the “size‐normalized weight” (SNW) of the planktonic foraminifer Neogloboquadrina dutertrei in core MD06‐3047B, representing a mid‐depth site (2.5 km) in the western tropical Pacific since 700 ka. On glacial‐interglacial timescales, deep‐water [CO32–] exhibits an inverse relationship with global sea‐level elevations, consistent with the “coral reef hypothesis” that the deep Pacific carbonate system responded to variations in shelf‐carbonate production through the past 700 kyr. On longer timescales, a decoupling between deep‐water [CO32–] and δ13C around the globe can be explained by a combination of continental weathering and nutrient inputs. During the mid‐Brunhes... Tipo: Text Palavras-chave: Planktonic foraminifer; Shell weight; Carbonate dissolution; Coral reef hypothesis; Carbon cycles; Ocean stratification. Ano: 2018 URL: https://archimer.ifremer.fr/doc/00455/56619/58322.pdf Registros recuperados: 3 Primeira ... 1 ... Última

Empresa Brasileira de Pesquisa Agropecuária - Embrapa Todos os direitos reservados, conforme Lei n° 9.610 Política de Privacidade Área restrita		Embrapa Parque Estação Biológica - PqEB s/n° Brasília, DF - Brasil - CEP 70770-901 Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco