Foraminíferos planctónicos y bentónicos del límite Cretácico/Terciario de Aín Settara, Tunicia: dos patrones de extincióndiferentes y una misma causa

• Autores: Ignacio Arenillas Sierra, Laia Alegret Badiola, José Antonio Arz Sola, Eustoquio Molina Martínez
• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 1, 2, 2000 (Ejemplar dedicado a: V Congreso Geológico de España (Alicante, 10-14 julio 2000)), págs. 331-334
• Idioma: español
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• Resumen

  • A detailed biostratigraphic and quantitative study based on foraminifera from the Ain Settarasection (Tunisia) allows us to infer two different extinction patterns in planktic and benthicforaminifera across the Cretaceous/Tertiary (K/T) boundary. More than 68% (and probably 97%)of the Maastrichtian planktic foraminifera! species, whereas only 21% of Maastricht!an benthicforaminiferaI species, became extinct in coincidence with the K/T boundary and the impact evidence. However, more than 51% of the benthic foraminifera! species suffer a Lazaro effect inthe lower most Danian, and infaunal benthic morphogroups drastically dropped just at the K/Tboundary, indicating a sudden breakdown of the food supply. Planktic foraminifera! catastrophic mass extinction and P/B ratio drop indicate a sudden decrease of the superficial-marine productivity. All these data suggest that the K/T foraminiferaI turn overs were linked with anasteroid impact.