Artigo

Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil

This research aimed to correlate the sedimentary transport with the diagenetic processes in the coastal zone and Amazon Continental Shelf (ACS). Physical and physical-chemical parameters, trace element contents (Cr, Pb, Ni, Zn and Hg), and O2, CO2 and iron flux were determined in sediment and por...

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Autor principal: APRILE, Fábio Marques
Outros Autores: SIQUEIRA, Gilmar Wanzeller, DARWICH, Assad José, IRION, Georg Friedrich
Grau: Artigo
Idioma: eng
Publicado em: SCIENCEDOMAIN International 2019
Assuntos:
Pore water
Mineralization
Net productivity
Sedimentary characterization
Diagenetic processes
Amazon continental shelf
Acesso em linha: http://repositorio.ufpa.br/jspui/handle/2011/11049
https://doi.org/10.9734/jgeesi/2019/v20i430113
id ir-2011-11049
recordtype dspace
spelling ir-2011-110492023-11-22T12:48:13Z Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil APRILE, Fábio Marques SIQUEIRA, Gilmar Wanzeller DARWICH, Assad José IRION, Georg Friedrich Pore water Mineralization Net productivity Sedimentary characterization Diagenetic processes Amazon continental shelf This research aimed to correlate the sedimentary transport with the diagenetic processes in the coastal zone and Amazon Continental Shelf (ACS). Physical and physical-chemical parameters, trace element contents (Cr, Pb, Ni, Zn and Hg), and O2, CO2 and iron flux were determined in sediment and pore water. Sedimentary incubation (96 hours) and algorithms were applied to determine the variation of the activity coefficient (ΔI) and ionic strength (Fi) of the predominant chemical species, and to estimate the net production and mineralization of the organic matter (ΔCO2T) in the system. There are not many studies applying incubation tests to identify the diagenetic processes, especially in fluvial-marines sediments. The results showed a strong zonation associated to the transport and deposition processes, influenced mainly by the grain-size and texture of sediment and fluvial streams. The distribution of trace elements followed the trend of the sedimentary pattern, with higher levels of metals in the deposits of clay minerals and organic matter. A factor of weight (Fw), calculated to establish the degree of importance of each parameter under the distribution and mobility of trace elements, suggests that the mobility of Cr, Ni and Zn is controlled by depth, clay and organic compounds contents, and concentration of dissolved oxygen.The vertical flow of O2 and CO2 and the Fe2+/Fe3+ ratio in the pore water suggest a predominance of organic matter oxidation in the sedimentary layer between 0.0 and 0.2 m, with partially anaerobic mineralization of the sediments below 0.4 m. Increases in trace element concentrations were observed in iron reduction zones, indicating processes of desorption of oxides and hydroxides of Fe and mineralization of organic matter. The extrapolation of the results of the incubation test to the studied system allowed to establish three hypotheses related to the diagenetic processes: 1) the flow of marine currents may be allowing the aerobic oxidation in the sandy sediments, with the nitrification route more accentuated than the ammonification route; 2) in the region of the coastal zone and inner continental shelf the routes of oxidation and reduction may be alternating according to the physical-chemical factors and seasonality; 3) in the coastal zone and inner shelf the net mineralization rate exceeded the net production rate of the organic matter (ΔCO2T >0). CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior SIQUEIRA, G. W. Universidade Federal do Pará 2019-04-23T22:27:10Z 2019-04-23T22:27:10Z 2019 Artigo de Periódico APRILE, Fabio Marques et al. Sedimentary transport influences on diagenetic processes at the Amazon Continental shelf, Brazil. Journal of Geography, Environment and Earth Science International, v. 20, n. 4, p. 1-16, 2019. DOI: http//:10.9734/JGEESI/2019/v20i430113. Disponível em: http://repositorio.ufpa.br/jspui/handle/2011/11049. Acesso em:. 2454-7352 http://repositorio.ufpa.br/jspui/handle/2011/11049 https://doi.org/10.9734/jgeesi/2019/v20i430113 eng Journal of Geography, Environment and Earth Science International Acesso Aberto application/pdf SCIENCEDOMAIN International Inglaterra Disponível na internet via correio eletrônico: riufpabc@ufpa.br
institution Repositório Institucional - Universidade Federal do Pará
collection RI-UFPA
language eng
topic Pore water
Mineralization
Net productivity
Sedimentary characterization
Diagenetic processes
Amazon continental shelf
spellingShingle Pore water
Mineralization
Net productivity
Sedimentary characterization
Diagenetic processes
Amazon continental shelf
APRILE, Fábio Marques
Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
topic_facet Pore water
Mineralization
Net productivity
Sedimentary characterization
Diagenetic processes
Amazon continental shelf
description This research aimed to correlate the sedimentary transport with the diagenetic processes in the coastal zone and Amazon Continental Shelf (ACS). Physical and physical-chemical parameters, trace element contents (Cr, Pb, Ni, Zn and Hg), and O2, CO2 and iron flux were determined in sediment and pore water. Sedimentary incubation (96 hours) and algorithms were applied to determine the variation of the activity coefficient (ΔI) and ionic strength (Fi) of the predominant chemical species, and to estimate the net production and mineralization of the organic matter (ΔCO2T) in the system. There are not many studies applying incubation tests to identify the diagenetic processes, especially in fluvial-marines sediments. The results showed a strong zonation associated to the transport and deposition processes, influenced mainly by the grain-size and texture of sediment and fluvial streams. The distribution of trace elements followed the trend of the sedimentary pattern, with higher levels of metals in the deposits of clay minerals and organic matter. A factor of weight (Fw), calculated to establish the degree of importance of each parameter under the distribution and mobility of trace elements, suggests that the mobility of Cr, Ni and Zn is controlled by depth, clay and organic compounds contents, and concentration of dissolved oxygen.The vertical flow of O2 and CO2 and the Fe2+/Fe3+ ratio in the pore water suggest a predominance of organic matter oxidation in the sedimentary layer between 0.0 and 0.2 m, with partially anaerobic mineralization of the sediments below 0.4 m. Increases in trace element concentrations were observed in iron reduction zones, indicating processes of desorption of oxides and hydroxides of Fe and mineralization of organic matter. The extrapolation of the results of the incubation test to the studied system allowed to establish three hypotheses related to the diagenetic processes: 1) the flow of marine currents may be allowing the aerobic oxidation in the sandy sediments, with the nitrification route more accentuated than the ammonification route; 2) in the region of the coastal zone and inner continental shelf the routes of oxidation and reduction may be alternating according to the physical-chemical factors and seasonality; 3) in the coastal zone and inner shelf the net mineralization rate exceeded the net production rate of the organic matter (ΔCO2T >0).
format Artigo
author APRILE, Fábio Marques
author2 SIQUEIRA, Gilmar Wanzeller
DARWICH, Assad José
IRION, Georg Friedrich
author2Str SIQUEIRA, Gilmar Wanzeller
DARWICH, Assad José
IRION, Georg Friedrich
title Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
title_short Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
title_full Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
title_fullStr Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
title_full_unstemmed Sedimentary transport influences on diagenetic processes at the Amazon continental shelf, Brazil
title_sort sedimentary transport influences on diagenetic processes at the amazon continental shelf, brazil
publisher SCIENCEDOMAIN International
publishDate 2019
url http://repositorio.ufpa.br/jspui/handle/2011/11049
https://doi.org/10.9734/jgeesi/2019/v20i430113
_version_ 1832602351925460992
score 11.755432

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