Sedimentary changes on the Southeastern Brazilian upper slope during the last 35,000 years

Anais da Academia Brasileira de Ciências

Michel M. Mahiques²  Marina M. Fukumoto¹  Ilson C.a. Silveira²  Rubens C.l. Figueira¹  Marcia C. Bícego²  Rafael A. Lourenço¹  Silvia H. Mello-e-sousa² 

[1] ,Universidade de São Paulo Instituto Oceanográfico Departamento de Oceanografia Física, Química e GeológicaSão Paulo SP ,Brasil

关键词: sedimentation;    accumulation rate;    upper slope;    Southeastern Brazil;    sedimentação;    taxa de acumulação;    talude superior;    Sudeste do Brasil;   

DOI  :  10.1590/S0001-37652007000100018

来源: SciELO

【 摘 要 】

A first evaluation of the sedimentary changes, including accumulation of inorganic and organic carbon on the upper slope off Southeastern Brazil under different climatic conditions, based on the analysis of a sedimentary core, is here presented. Results indicate that sedimentation rate as well sedimentary characteristics, including the nature of the organic carbon deposited during the LGM (Last Glacial Maximum), were different from the present deposition, indicating higher primary productivity during the LGM, to be accounted for by the higher values of marine organic carbon. Nevertheless, the higher values of Accumulation Rate of calcium carbonate and organic carbon can be credited to the higher values of the sedimentation rates. Conditions prevailing during Isotope Stage 3 may be considered intermediate as between the LGM and the present day. The conditions for a higher primary productivity associated with the deposition of finer terrigenous sediments may be explained as a response to the off shoreward displacement of the main flow of the Brazil Current.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License