scholarly journals Hyporheic Passive Flux Meters Reveal Inverse Vertical Zonation and High Seasonality of Nitrogen Processing in an Anthropogenically Modified Stream (Holtemme, Germany)

2017 ◽  
Vol 53 (12) ◽  
pp. 10155-10172 ◽  
Author(s):  
Julia Vanessa Kunz ◽  
Michael D. Annable ◽  
Suresh Rao ◽  
Michael Rode ◽  
Dietrich Borchardt

Ecology ◽  
1950 ◽  
Vol 31 (4) ◽  
pp. 647-649 ◽  
Author(s):  
J. Arnold Shotwell
Keyword(s):  


The early stages of burial diagenesis involve the reactions of various oxidizing agents with organic matter, which is the only reducing agent buried with the sediment. In a system in which a local equilibrium is established, thermodynamic principles indicate that, inter alia , manganese, iron and sulphate should each be consumed successively to give rise to a clearly characterized vertical zonation. However, ferric iron may not react fast enough and the relative rates of reduction of Fe III and sulphate not only control the formation of iron sulphide and associated carbonate but also may lead to extreme chemical and isotopic dis-equilibrium. This produces kinetically controlled ‘micro -environments’. On a larger scale, sulphide will diffuse upward to a zone in which its oxidation leads to a reduction of pH. The various dramatic changes in chemical environment across such an interface cause both dissolution and precipitation reactions. These explain common geological observations: the occurrence of flint nodules (and their restriction to chalk hosts) and the association of phosphate with glauconite.



2006 ◽  
Vol 53 (1) ◽  
pp. 48-61 ◽  
Author(s):  
Lesley E. Blankenship ◽  
A. Aristides Yayanos ◽  
Donald B. Cadien ◽  
Lisa A. Levin




2020 ◽  
Vol 245 ◽  
pp. 106791 ◽  
Author(s):  
Tania Montes ◽  
Elisa Guerrero-Feijóo ◽  
Víctor Moreira-Coello ◽  
Antonio Bode ◽  
Manuel Ruiz-Villarreal ◽  
...  


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