Water mass reconstruction by Nd isotopic analysis from Mid Atlantic oceanic sediments

• Autor(a) principal: Ferreira, maria Luiza de Carvalho [UNESP]
• Data de Publicação: 2013
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/119049
• topic: Geologia estratigráfica; Espectrometria de massa; Sedimentos marinhos; Neodímio - Isótopos; Atlantico, Oceano

Nd isotopic information obtained of Fe-Mn oxyhydroxide coatings marine sediment is used to reconstruct the interplay of water masses in the Mid Atlantic Ocean during the past 22 ka. The method consist of leaching those coatings and measure in Mass Spectrometer to define the εNd values (ε notion that compare the ratio 143Nd/144Nd in terms of their deviation from the Chondritic Uniform Resevoir (CHUR) evolution line) correspondent to past bottom sea water. The radiogenic or unradiogenic parameter of waters with Southern and Northern source (SSW and NSW) was captured for the sediments coating and is used to identify their influence in the surrounded area of the studied core at 22 000 years until present. The core is localized in Mid Atlantic Ocean and was collected in the IODP program in site 306 core U1313. The results had presented convinced records, giving evidence that during Holocene deep waters did not experience distinguished changes; the influence of NSW indicating a reduce but not the shutdown of deep water formation in North Atlantic during LGM; and the record data suggest possible contributions of eastern water mass into Mid Atlantic during glacial time