Ichnological analysis: a useful tool to approach eco-sedimentary parameters in deep-sea environments

• Francisco J. Rodríguez-Tovar ^[1] ; Alfred Uchman ^[2]
  1. [1] Universidad de Granada

     Universidad de Granada

     Granada, España

     
  2. [2] Jagiellonian University, Institute of Geological Sciences
• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 11, 2010 (Ejemplar dedicado a: Deep-Water Circulation: Processes & Products. International Congress. Baitona, Pontevedra, Spain. 16 & 17 June 2010), págs. 149-150
• Idioma: inglés
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• Resumen

  • Ichnological analysis through the Cenomanian-Turonian transition from deep-sea sediments, correspondingto the Oceanic Anoxic Event -2, reveals significant changes in abundance and diversity of trace fossils as well as inichnofabrics. Higher abundance and diversity of trace fossils in the pre- and post-OAE-2 intervals, accords with agenerally good oxygenation, but punctuated by short periods of anoxia (absence of trace fossils and bioturbationalstructures) or dysaerobic conditions (one ichnotaxon, some bioturbational structures). The analysis shows that theOAE-2 interval is not a single event, but it is composed of several short-term anoxic events interrupted by shorterdysaerobic and oxic events favouring an ephemeral colonization. Variations in ichnological features reveal as veryuseful to recognize oxygenation changes in deep-water environments as those related to deep-bottom currentcirculation.