Is the «Ventian» a Real Stratigraphic Stage?
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MUESTRA SUMARIO Código ___ .:;¿_J.o .. ~. .D .o.o6. ..... Año ...... ..... .. .A. j~8. ....... ... ·· ········· A. GUERRA MERCHÁN, J.A. MARTÍN RRANO. El Mioceno superior de la Depresiór en el sector de Caniles. Implicaciones paleogeográ- ficas ........................................ ;................................... 5 F. SERRANO. Sobre la edad del comienzo de la actividad magmáti- ca en Sierra de Gata (Aimería, España) ... ... .............. 17 S. CALZADA. Una nueva especie de Monticlarella (Brachiopoda) del Cretácico alicantino .................................................... 25 C. SANZ DE GALDEANO. The evolution, importance and significance of the Neogene fault system within the Betic-Rifean Domain . 33 M. IÑESTA. Braquiópodos liásicos del Cerro de la Cruz (La Roma- na, Prov. Alicante, España) .. .. .. .. .. .... .. .. .. .. 45 MARÍA TERESA ALBERDI Y FRANCESCO PAOLO BONA DONNA. ls the «Ventian» a :eal stratigraphic stage? ....... ..... :. 65 MANUEL POZO RODRIGUEZ Y ANGEL MORENO GUTIE RREZ. Estudio mineralógico de materiales detríticos del ter- ciario de La Unión (Murcia) ....................................... 79 M. GUTIÉRREZ ELORZA Y A. ESTÉVEZ. Depósitos periglaciales en la vertiente septentrional de la Sierra de Lújar. Implicaciones Neotectónicas . 95 MARÍA TERESA ALBERDI Y PLINIO MONTOYA. Hípparíon medíterraneum Roth & Wagner, 1855. (Pe rissodactyla, Mammalia7 del yacimiento de Turoliense inferior de Crevillente (Alicante, España) .. .. .. 107 MED/TERRANEA SERIE DE ESTUDIOS GEOLÓGICOS Número 7 1988 SUMARIO Página A. GUERRA MERCHÁN, J.A. MARTÍN PÉREZ Y F. SE RRANO. El Mioceno superior de la Depresión de Guadix-Baza en el sector de Caniles. Implicaciones paleogeográ- ficas ............................................................................ 5 F. SERRANO. Sobre la edad del comienzo de la actividad magmáti- ca en Sierra de Gata (Aimería, España) . .. .. .. 17 S. CALZADA. Una nueva especie de Monticlarella (Brachiopoda) del Cretácico alicantino .................................................... 25 C. SANZ DE GALDEANO. The evolution, importance and significance of the Neogene fault system within the Betic-Rifean Domain . 33 M. IÑESTA. Braquiópodos liásicos del Cerro de la Cruz (La Roma- na, Prov. Alicante, España) ........................................ 45 MARÍA TERESA ALBERDI Y FRANCESCO PAOLO BONA DONNA. ls the «Ventian» a :eal stratigraphic stage? ············:· 65 MANUEL POZO RODRIGUEZ Y ANGEL MORENO GUTIE RREZ. Estudio mineralógico de materiales detríticos del ter- ciario de La Unión (Murcia) ..... -.................................. 79 M. GUTIÉRREZ ELORZA Y A. ESTÉVEZ. Depósitos periglaciales en la vertiente septentrional de la Sierra de Lújar. Implicaciones Neotectónicas . 95 MARÍA TERESA ALBERDI Y PLINIO MONTOYA. Hipparion mediterraneum Roth & Wagner, 1855. (Pe rissodactyla, Mammalia7 del yacimiento de Turoliense inferior de Crevillente (Alicante, España) ................... 107 DEPARTAMENTO DE GEOLOGÍA- FACULTAO DE CIENCIAS UNIVERSIDAD DE ALICANTE SERIE DE ESTUDIOS GEOLÓGICOS Mediterránea Ser. Geol. 1988 ANEJO DE LOS ANALES DE LA UNIVERSIDAD DE ALICANTE Redacción: A. ESTÉVEZ, C. AURNHEIMER y J.A. PINA Secretario: J.M. SORIA EDITA: Servicio de Publicaciones de la Universidad de Alicante I.S.S.N.: n. 0 0210-5004 Depósito Legal: A-927-1983 Composición e Impresión: Gráficas ESTILO, S. C. General Elizaicin, 11 - Tel. 520 69 79 ALICANTE Correspondencia: Departamento de Ciencias Ambientales y Recursos Naturales. (División de Geología) Facultad de Ciencias de la Universidad de Alicante Teléfono 566 11 50. Extensión 1.190 Apartado 99 ALICANTE PUBLICACIÓN PATROCINADA POR: ~ GENERALITAT VALENCIANA ~ CONSELLERIA D'OBRES PUBLIQUES, URBANISME 1TRANSPORTS Y CAJA DE AHORROS PROVINCIAL DE ALICANTE Mediterranea Ser. Geol. (1988}, n. a 7. Pag. 65-77 IS THE «VENTIAN» A REAL STRATIGRAPHIC STAGE? por MARfA TERESA ALBERDI (1) FRANCESCO PAOLO BONADONNA (2) ABSTRACT The «Ventian», term described by Aguirre et al. (1976), needs a better definition of its upper and lower boundaries. A detailed geological, stratigraphical and paleontological analysis of the localities of Venta del Moro, Sahabi, Casino and Baccinello V3, comparing them with other for mer and latter ones in time, indicate that the « Ventian» could very well represent fauna no longer Turolian and not yet Ruscinian and therefore should be limited in time regarding the described by its authors. Its base should be directly overlying the last evaporitic episodes of the Upper Mes sinian (sensu Ruggieri et a/, 1969) and therefore younger than 6.5 MA (datum given by the aut hors of the «Ventian») while its upper limit should coincide with the beginning of the Ruscinian fauna. Two possibilities can be stated for the stratigraphical succession, one in which the base of the «Ventiam> still corresponds to the Upper Messinian and another in which the «Ventiam> is considered the beginning of the Pliocene. The possible «Ventian» stratotype, in this case, that in our opinion is the most realistic, should be established on the Sahabi deposit due to its great faunistic variability and its well defined geological and stratigraphical situation. RESUMEN El Ventiense, termino acufiado por Aguirre et al. (1976) necesita una mejor definici6n de su limite inferior y superior. Un ancilisis detallado de la geologia, estratigrafia y paleontologia de las localidades de Venta del Moro, Sahabi, Casino y Baccinello V3, comparada con otras anterio res y posteriores en el tiempo indican que el Ventiense bien podria representar una fauna ya no Turoliense y todavia no Rusciniense. Por ello deberia ser limitada en el tiempo con respecto a lo dicho por sus autores. Su base deberia estar directamente apoyada sobre Ios ultimos episodios evaporiticos del Mesiniense superior (sensu Ruggieri et al., 1969) y por tanto mas joven de 6,5, MA; mientras ellirnite superior deberia coincidir con el inicio de la fauna rusciniense. La sucesi6n estratigrafica puede plantearse con dos possibilidades: una hip6tesis en la que la base del Ventien se corresponde al Mesiniense superior y su termino al Plioceno no Rusciniense. Otra hip6tesis con sidera el Ventiense como el inicio del Plioceno y no a caballo entre el Mioceno y el Plioceno. El estratotipo del Ventiense, en su caso, deberia establecerse sobre el yacimiento de Sahabi por tener este una gran variedad faunistica y una situaci6n geol6gica y estratigrafica bien definida. KEY WORDS: Ventian, Miocene/Pliocene boundary, Lowermost Pliocene, Baccinello V3, Casino, Sahabi, Venta del Moro. (1) Museo Nacional de Ciencias Naturales, CSIC-Jose Gutierrez Abascal2, 28006 Madrid (Spain). (2) Dipartimento di Scienze della Terra, Via Santa Maria 53, 56100 Pisa (Italy). 65 INTRODUCTION In 1976 Aguirre et al. proposed a new mammal zone, the «Ventian» for the transition forms between the Turolian s.s. levels and the Early Pliocene ones; in this mammal zone they included also the forms of the Lower Messi nian levels. In the stratigraphic schemes there is a gap between the Turolian faunas and the Ruscinian ones; this empty space cannot be filled by the last Turolian faunas or by the first Ruscinian ones. With regard to this assertion we can quote Hurzeler & Engesser (1976); these authors emphasize, in the lig nitiferous Baccinello series, the great difference between the V2 fauna (about 8 MA) and the V3 one with Hipparion. In the point of view of Aguirre et al. (1976) and Alberdi et al. (1977) the «Ventian» comprises the Librilla and Crevillente-6 faunal deposits that are deposits with typical Turolian fauna for the presence of more primitive forms of concudense-mediterraneum type Hypparion and Gorafe 1 level, already Ruscinian (Ruiz Bustos et al., 1984). We think that the stratigraphic value of «Ventian» has to be better defin ed; that is, it is necessary to fix a time span more restricted and with more exactly fixed temporal boundaries. DISCUSSION Between the end of Tortonian and the general Pliocene transgression in the Mediterranean basin, the geologic history is represented by a quick succes sion of events in a very short time span; that is between 7 MA (a little before the Tortonian-Messinian boundary) and 5 MA (a little after the Miocene Pliocene boundary). Ruggieri (1966, 1967) stands out a particular tectonics that begun in the Upper Tortonian and it was charactherized by two crises separa ted by a pause period: the first crisis took place at the end of the Tortonian, the second one at the end of the Lower Pliocene. In this period, between 7 and 5 MA, there were many lacustrine basins in the Mediterranean basin, in which the lignite was made up easily, basins due probably to the tectonics which cut away the connexion between the sea and some coastal basins (fig. 1) and to the strong wetness that not allowed the formation of evaporites but, on the contrary, supported the luxuriant growth of the vegetation. We think that the Gravitelli (Messina) basin, the lower lacustrine cycle of the Casino (Siena) and the V1 and V2 levels of Baccinello series (Grosseto) may be assigned to this phase. The Gravitelli deposit had a fauna that cannot be contrasted as now it is lost; its stratigraphy is very clear and it was well described (see Seguenza, 1902; Ruggieri et al., 1969). The fauna seems to have some contradictory ele ments, regarding taxonomy not as faunal association, as in the case of the mas todon and the hippopotamus. The two quoted mastodons should correspond to one only type (Kotsakis, 1987, p. 73); according to the Seguenza's plates, both may