This is the first extensive study of REE in sediments from 12 estuaries along the Eastern Atlantic Coast in Brazil (i.e., Bahia: Jaguaripe, Paraguaçu, São Paulo, Mataripe, Subaé, Serinhaem, and Maraú; Pernambuco: Capibaribe and Santa Cruz Channel; and Espírito Santo: Doce, Piraquê Açú, and Vitória Bay). Here we quantified the abundances and determined the sources and fractionation of REE and Y. Concentrations of Al, Fe, and Mn were also evaluated to comprehend the influence of diagenetic remobilization. The ƩREEY varied from 6 mg kg^-1 (Santa Cruz Channel; >90% sand) to 336 mg kg^-1 (Piraquê-Açú; 50% silte+clay). Abundances of REE normalized by post-Archean Australian shale (PAAS) tended to be enriched in light REE (LREE; La to Nd) over heavy REE (HREE; Er to Lu). The estuaries Capibaribe, Jaguaripe, Paraguaçu, São Paulo, Mataripe, Subaé, and Doce River showed MREE enrichment. Five estuaries showed a significant positive correlation between ƩREEY and Al, Fe, and Mn. LREE showed a significant correlation with Al (r²>0.7) and Fe (r²>0.8) for most studied areas. REE were significantly correlated to Mn (r²>0.8) only for 5 estuaries. The bottom types and positions along the estuarine zones influence REEY, Al, Mn, and Fe concentrations. Anthropogenic activities are not impacting REE distribution and fractionation. The REE abundances observed here corroborate the characterization of the estuaries of Brazil’s east coast and can be used as a background for the region.

Primary Presenter: Franciele Novais, Universidade Federal da Bahia (novais1992@hotmail.com)

Authors:

Vanessa Hatje, Universidade Federal da Bahia  (vhatje@ufba.com)