IMIS | Vlaams Instituut voor de Zee
 

Vlaams Instituut voor de Zee

Platform voor marien onderzoek

IMIS

Publicaties | Instituten | Personen | Datasets | Projecten | Kaarten
[ meld een fout in dit record ]mandje (0): toevoegen | toon Print deze pagina

Diagenetic formation of gypsum and dolomite in a cold-water coral mound in the Porcupine Seabight, off Ireland
Pirlet, H.; Wehrmann, L.M.; Brunner, B.; Frank, N.; Dewanckele, J.; Van Rooij, D.; Foubert, A.; Swennen, R.; Naudts, L.; Boone, M.; Cnudde, V.; Henriet, J.-P. (2010). Diagenetic formation of gypsum and dolomite in a cold-water coral mound in the Porcupine Seabight, off Ireland. Sedimentology 57(3): 786-805. https://dx.doi.org/10.1111/j.1365-3091.2009.01119.x
In: Sedimentology. Wiley-Blackwell: Amsterdam. ISSN 0037-0746; e-ISSN 1365-3091, meer
Peer reviewed article  

Beschikbaar in  Auteurs 
    VLIZ: Open Repository 214842 [ OMA ]

Trefwoorden
    Lophelia Milne Edwards & Haime, 1849 [WoRMS]
    Marien
Author keywords
    Cold-water coral; dolomite; early diagenesis; gypsum; Lophelia; Porcupine Seabight; sulphur isotopes

Auteurs  Top 
  • Pirlet, H., meer
  • Wehrmann, L.M.
  • Brunner, B.
  • Frank, N.

Abstract
    Authigenic gypsum was found in a gravity core, retrieved from the top of Mound Perseverance, a giant cold-water coral mound in the Porcupine Basin, off Ireland. The occurrence of gypsum in such an environment is intriguing, because gypsum, a classic evaporitic mineral, is undersaturated with respect to sea water. Sedimentological, petrographic and isotopic evidence point to diagenetic formation of the gypsum, tied to oxidation of sedimentary sulphide minerals (i.e. pyrite). This oxidation is attributed to a phase of increased bottom currents which caused erosion and enhanced inflow of oxidizing fluids into the mound sediments. The oxidation of pyrite produced acidity, causing carbonate dissolution and subsequently leading to pore-water oversaturation with respect to gypsum and dolomite. Calculations based on the isotopic compositions of gypsum and pyrite reveal that between 21·6% and 28·6% of the sulphate incorporated into the gypsum derived from pyrite oxidation. The dissolution of carbonate increased the porosity in the affected sediment layer but promoted lithification of the sediments at the sediment-water interface. Thus, authigenic gypsum can serve as a signature for diagenetic oxidation events in carbonate-rich sediments. These observations demonstrate that fluid flow, steered by environmental factors, has an important effect on the diagenesis of coral mounds.

Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid Top | Auteurs