Publication: Evolución sedimentaria de las cuencas lacustres neógenas de la
zona pre bética ( Albacete, España). Relación, posición y
efectos del vulcanismo durante la evolución. Interés minero.
Loading...
Official URL
Full text at PDC
Publication Date
1988
Authors
Elizaga, E.
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Instituto Geológico y Minero de España (Madrid)
Citations
Exportar
Abstract
Las cuencas neógenas continentales del Prebético presentan un relleno sedimentario potente que aparece estructurado en dos unidades tectosedimentarias superpuestas, las cuales abarcan una gran parte del Mioceno Superior (Vallesiense Medio-Turoliense). Dichas unidades están compuestas esencialmente por sedimentos lacustres, diferenciándose en ellas cinco tramos caracterizados por facies diferentes. En la unidad tectosedimentaria inferior se distinguen: Facies A, constituidas por cuerpos conglomeráticos tabulares que intercalan niveles de lutitas laminadas; Facies B, formadas fundamentalmente por areniscas canalizadas, lutitas y margas; Facies C, caracterizadas por niveles evaporíticos (yesos con nódulos de azufre) que evolucionan en la vertical a margas y carbonatos con presencia creciente de niveles diatomíticos. Por su parte, la unidad tectosedimentaria superior está formada por: Facies D, constituidas por depósitos slumpizados y turbiditas; y Facies E, consistentes en una sucesión monótona de diatomitas y carbonatos con intercalaciones de porcelanitas. Las dos unidades distinguidas están separadas por una discontinuidad de carácter regional que está en relación con un evento sísmico importante, con manifestaciones volcánicas asociadas de carácter lamproítico. Como resultado del análisis del relleno de las cuencas, se distinguen dos etapas distensivas dentro del contexto extensional general del área bética durante el Mioceno Superior: una primera etapa distensiva que condiciona la formación de estas cuencas durante el Tortoniense, y una segunda etapa, intra-Messiniense, que supone una reactivación importante en su relleno, con incidencia de eventos sísmicos y vulcanismo. Dichas etapas, marcadas por discontinuidades mayores, tienen su equivalente correlativo en otras cuencas neógenas de la Península.
Continental Neogene basines of the Prebetic zone contain a thick sedimentary fill consisting of two superimposed tectono-sedimentary units, roughly upper Miocene in age. These units are esentially composed of lacustrine sediments, where five different facies levels have been distinguished. In the lower tectono-sedimentary unit the following facies may be discerned: Facies A, formed by tabular conglomeratic bodies in which horizons of laminated lutites are inserted; Facies B, basically constituted by channeled sandstones, lutites and marls: Facies C, characterized by evaporite horizons and sulphur nodules whitin gypsum, in which marls and carbonates become more abundant to the top of the sequence together with increasing presence of diatomite levels. The upper tectono-sedimentary unit is formed by: Facies D, with turbidites and slump deposits, and Facies E, consisting of a monotonous alternation of diatomites and carbonates. These two main units are separated by a discontinuity which has been also recognized in other regions. The discontinuity is marked by an important seismic event with associated volcanism of lamproitic character. As a result of the undertaken analysis two distensive stages are distinguished within the general extensive context. The first one took place during the Tortonian and it corresponds to the initial configuration of the basins. During the second stage (intra-Messinian) the filling of this basin was significantly stimulated by seismic activity with associated volcanism. These two stages can be correlated with similar events in other Neogene basins of Iberia.
Continental Neogene basines of the Prebetic zone contain a thick sedimentary fill consisting of two superimposed tectono-sedimentary units, roughly upper Miocene in age. These units are esentially composed of lacustrine sediments, where five different facies levels have been distinguished. In the lower tectono-sedimentary unit the following facies may be discerned: Facies A, formed by tabular conglomeratic bodies in which horizons of laminated lutites are inserted; Facies B, basically constituted by channeled sandstones, lutites and marls: Facies C, characterized by evaporite horizons and sulphur nodules whitin gypsum, in which marls and carbonates become more abundant to the top of the sequence together with increasing presence of diatomite levels. The upper tectono-sedimentary unit is formed by: Facies D, with turbidites and slump deposits, and Facies E, consisting of a monotonous alternation of diatomites and carbonates. These two main units are separated by a discontinuity which has been also recognized in other regions. The discontinuity is marked by an important seismic event with associated volcanism of lamproitic character. As a result of the undertaken analysis two distensive stages are distinguished within the general extensive context. The first one took place during the Tortonian and it corresponds to the initial configuration of the basins. During the second stage (intra-Messinian) the filling of this basin was significantly stimulated by seismic activity with associated volcanism. These two stages can be correlated with similar events in other Neogene basins of Iberia.