Bioestratigrafía y reconstrucción paleoambiental del tránsito Cretácico-Paleógeno en El Mimbral (México)

• L. Alegret ^[1] ; I. Arenillas ^[2] ; Jose A. Arz ^[2] ; E. Molina ^[2]
  1. [1] University College London

     University College London

     Reino Unido

     
  2. [2] Universidad de Zaragoza

     Universidad de Zaragoza

     Zaragoza, España

     
• Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 6, 4, 2004 (Ejemplar dedicado a: VI CONGRESO GEOLÓGICO DE ESPAÑA (Zaragoza, 12-15 julio, 2004)), págs. 357-360
• Idioma: español
• Enlaces
  • Texto Completo Ejemplar
• Resumen

  • Upper Cretaceous and Lower Paleogene benthic and planktic foraminifera from the El Minibral section (Mexico) were analysed in order to infer the biostratigraphy and the paleoenvironmental turnover across the Cretaceous/Paleogene (K/Pg) boundary. In the El Mimbral section, the UpperCretaceous marly Méndez and the Lower Paleogene marly Velasco Formations are separated by a0.5 to ~3 m-thick-Clastic Unit. We studied the upper 2 m of the Méndez Formation and the lowermost 3 m of the Velasco Formation, comprising the upper Maastrichtian A. mayaroensis and P.hantkeninoides Biozones, and the lower Danian G. cretacea and Pv. eugubina Biozones, respectively. Planktic foraminifera were affected by a catastrophic extinction at the K/Pg boundary, whereas benthic foraminifera show reorganization of the community structure rather than significantextinction. The benthic foraminiferal turnover may have resulted from the drop in primary productivity after the asteroid impact at the K/Pg boundary.