Bioeventos paleoceanográficos en el Cenomaniense de la Cuenca Vasca occidental: señales micropaleontológicas y geoquímicas

Detailed micropaleontologic and isotopic data from the Cenomanian of the Leioa section (Basque Basin, Northern Spain) show the existence of four bioevents, one located in the lower Cenomanian (R. brotzeni biozone) two in the middle Cenomanian (Rotalipora reicheli biozone; base of R. cushmani biozone...

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Detalles Bibliográficos
Autores: Rodríguez Lázaro, Julio, Elorza, Javier, García Garmilla, Francisco, Garcia Zarraga, E., Pascual, Ana
Tipo de recurso: artículo
Fecha de publicación:1995
País:España
Institución:Universidad de Huelva (UHU)
Repositorio:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Idioma:español
OAI Identifier:oai:ariasmontano.uhu.es:10272/13358
Acceso en línea:http://hdl.handle.net/10272/13358
Access Level:acceso abierto
Palabra clave:Marine bioevents
Biotic response
8,13C and 8&apos
18O isotopes
Cenomanian
Basque Basin
Descripción
Sumario:Detailed micropaleontologic and isotopic data from the Cenomanian of the Leioa section (Basque Basin, Northern Spain) show the existence of four bioevents, one located in the lower Cenomanian (R. brotzeni biozone) two in the middle Cenomanian (Rotalipora reicheli biozone; base of R. cushmani biozone) and the fourth in the middle-upper Cenomanian boundary (R. cushmani biozone). Each bioevent is defined by drastic changes in the microfaune dynamics (planktonic and benthonic foraminifers and ostracodes) as well as by the isotopic signals o f <S” C and S ,80 . Two kinds o f bioevents may be defined in this basin: 1) those with an increase of the benthic diversities, that are associated with shallowing, nutrient increase and light lithologies, and 2) those with decreasing diversities of the benthonics, that are accompanied by deepening, nutrient decrease and dark lithologies. After the analysis of the geochemical and biological proxies in these materials, several causes related to thermic and dynamic behaviour of protoatlantic water-masses can be assigned to explain the observed bioevents