Počet záznamů: 1  

Cementation and blackening of Holocene sands by peat-derived humates: A case study from the Great Dune of Pilat, Landes des Gascogne, Southwestern France

  1. 1.
    0425586 - USMH-B 2014 RIV NL eng J - Článek v odborném periodiku
    Suchý, V. - Sýkorová, Ivana - Havelcová, Martina - Machovič, Vladimír - Zeman, Antonín - Trejtnarová, Hana
    Cementation and blackening of Holocene sands by peat-derived humates: A case study from the Great Dune of Pilat, Landes des Gascogne, Southwestern France.
    International Journal of Coal Geology. Roč. 114, JUL (2013), s. 19-32. ISSN 0166-5162
    Grant CEP: GA ČR GA205/09/1162; GA ČR(CZ) GA13-18482S
    Institucionální podpora: RVO:67985891 ; RVO:68378297
    Klíčová slova: humate * peat * cementation * aeolian sand
    Kód oboru RIV: DB - Geologie a mineralogie
    Impakt faktor: 3.313, rok: 2013

    The base sand layers of the aeolian Great Dune of Pilat, which stretches along the coast of Arcachon Bay, have been locally impregnated with a dark brown to black amorphous organic substance of humate composition. The humate-cemented sand forms a well-indurated horizon 40-50 cm in thickness that developed immediately beneath the Holocene peaty layer (P1 "paleosoil"). The humate, identified by means of FT-IR and Raman micro-spectroscopy, acted both as a cementing agent and as a coloring agent; it formed thin coats and meniscus cements between individual sandstone grains which, in turn, caused the dark, asphaltic-like appearance of the sandstone. Field observations, combined with geochemical analyses, and the presence of identical geochemical compounds recognized in the peat and sandstone humate cement, suggest that the peat-containing low-coalified (R-r = 0.2%) fragments of higher, submerged and floating plants and marine algae deposited in a saline and reducing environment served as an obvious source rock for the humate. The humate derived from decaying organic remains that descended from the peat into the permeable sand, where it indurated irreversibly over a period shorter than 3500 years.
    Trvalý link: http://hdl.handle.net/11104/0231416