Perfiles paleokársticos en el techo de la unidad intermedia del mioceno de la cuenca de Madrid

An intra-Vallesian (Upper Miocene) paleokarst developed at the top of the Intermediate Miocene Unit in the continental Madrid basin is recognized. This paleo karst is an early shallow, tabular-shaped karst that shows a marked control by the depositional facies pattern and lithologies. By integrating...

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Detalles Bibliográficos
Autores: Cañaveras, Juan Carlos, Sánchez-Moral, Sergio, Ordóñez, Salvador, Calvo Sorando, J. P.
Tipo de recurso: artículo
Fecha de publicación:2003
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/2336
Acceso en línea:http://hdl.handle.net/10261/2336
Access Level:acceso abierto
Palabra clave:Paleokarst
Meteoric diagenesis
Miocene
Madrid Basin
Descripción
Sumario:An intra-Vallesian (Upper Miocene) paleokarst developed at the top of the Intermediate Miocene Unit in the continental Madrid basin is recognized. This paleo karst is an early shallow, tabular-shaped karst that shows a marked control by the depositional facies pattern and lithologies. By integrating morphological, petrologic and geochemical data, three hydrogeological or environmental zones have been established throughout the paleokarstic profiles: (i) a vadose zone, characterized by vertically elongated caves and discontinuous speleothems and vadose cements (ii) a 3-7 thick water table fringe, characterized by the wide development of stratiform breccia bodies, the superimposition of both vadose and phreatic features, and the lowest Fe and Mn contents in host-rock carbonates; and (iii) a phreatic zone characterized by an increase of δC-13 values and the predominance of phreatic cementation. The paleographic reconstruction for the intra-Vallesian paleokarst using paleokarstic profiles reveals relative topographic highs to the north and topographic lows to the south drawing the paleokarst landscape.