Ichnological evidence of Megalosaurid Dinosaurs crossing Middle Jurassic tidal flats

A new dinosaur tracksite in the Vale de Meios quarry (Serra de Aire Formation, Bathonian, Portugal) preserves more than 700 theropod tracks. They are organized in at least 80 unidirectional trackways arranged in a bimodal orientation pattern (W/NW and E/SE). Quantitative and qualitative comparisons reveal that the large tridactyl, elongated and asymmetric tracks resemble the typical Late JurassicEarly Cretaceous Megalosauripus ichnogenus in all morphometric parameters. Few of the numerous tracks are preserved as elite tracks while the rest are preserved as different gradients of modified true tracks according to water content, erosive factors, radial fractures and internal overtrack formations. Taphonomical determinations are consistent with paleoenvironmental observations that indicate an inter-tidal flat located at the margin of a coastal barrier. The Megalosauripus tracks represent the oldest occurrence of this ichnotaxon and are attributed to large megalosaurid dinosaurs. Their occurrence in Vale de Meios tidal flat represents the unique paleoethological evidence of megalosaurids moving towards the lagoon, most likley during the low tide periods with feeding purposes

Opaline chert nodules in maar lake sediments from Camp dels Ninots (La Selva Basin, NE Spain)

Chert nodule samples from three different well cores (CC, CP1 & CA) from the lacustrine infill of the Camp dels Ninot maar-diatreme (La Selva Basin) have been studied by means of X-ray diffraction, and optical and electron microscope technique. The chert nodules replace diatomites and carbonates layers, and varies in mineralogy between opal-A to opal-A/CT. The microtexture of the opal-A rich nodules is characterized by smooth microspheres of ~2μm in diameter that forms aggregates of amalgamated microspheres. Commonly, the nodules contain diatoms and their moulds when replacing diatomites, and dolomite or ankerite crystals and their moulds when replacing carbonates. The opal-A/CT rich nodules exhibit a microtexture consisting of microspheres of ~8μm in diameter that form aggregates with botryoidal and finger-like morphologies. Results indicate that the early diagenetic transformation of opal-A to opal-CT is not complete in the studied sediments.Peer Reviewe

A calibrated mammal scale for the Neogene of Western Europe. State of the art

A magnetobiostratigraphically calibrated mammal scale for the Neogene of Western Europe is presented in this paper. The Mammal Neogene MN units originally proposed by Mein [Report on activity RCMNS-Working groups] 1975 have been re-defined here on the basis of first appearances of selected small and large mammal taxa. The chronology of the lower boundaries of each unit had been established mostly after the significant magnetobiostratigraphic framework developed in the last decade in a number of Spanish basins: Ebro, Calatayud-Daroca, Vallès-Penedès, Teruel, Fortuna, Cabriel and Guadix-Baza. In the case of the early and middle Miocene particularly, MN 1, MN 2 and MN 3 , the authors have also taken into account the magnetobiostratigraphic framework developed in the North Alpine Foreland Basin. Some alternative correlations of the magnetostratigraphic data from this last basin are proposed in order to achieve a higher degree of consistence with the data from the Iberian basins. A quite well established magnetostratigraphic calibration of the MN boundaries can be proposed for most of the Neogene, from Middle Miocene to Late Pliocene. On the other hand, the chronological boundaries of the Early Miocene MN units are still poorly constrained due to: (1) scarcity of well-studied, continuous, thick magnetostratigraphic sections; (2) the difficulty in defining the boundaries of the MN zones for this time-span due to the relative homogeneity and persistence of the fossil rodent faunas and the absence of significant large mammal dispersal events. Some of the troubles which arise with the application of the MN units strengthen the need to take into account the palaeobiogeographical meaning of these units and their real suitability to date and correlate through extensive geographic areas

Maar-diatreme infill features recorded in borehole imaging

Oriented borehole images recorded with an ultrasonic acoustic televiewer and continuous coring recovery has allowed the characterization of different facies and volcanic processes involved in the infill of a maar-diatreme volcano type. Maar-diatremes are associated with strong explosions throughout most of their development, focused along feeder dikes and generally attributed to magma-water interaction. In the case study of Camp dels Ninots maar-diatreme (Girona, Spain) we have recognized four facies types located in the center of the maar-diatreme: volcanic ash, phreatomagmatic breccia with lithics and juveniles, vesicular pyroclasts (scoria), massive basalt or welded pyroclastic fragments. Ultrasonic televiewer images allow to characterize the different volcanic facies, since they display a different degree of reflectivity and textures. Other features such as fracturing and grain size can be directly measured on the images.Projects 2014-100575 from Departament de Cultura de and SGR2014-901 from AGAUR (both from Generalitat de Catalunya) financed the drilling campaigns.Peer Reviewe

El GEOCAMP : un sitio web y una herramienta de edición para las actividades de campo en Geología

El GEOCAMP es un portal informático de apoyo a las actividades de campo en Geología. Es un sitio web de libre acceso a disposición de docentes y estudiantes que realizan prácticas de campo como parte de sus enseñanzas o aprendizajes. Es un espacio hipermedia que contiene materiales didácticos de producción propia y numerosos enlaces a todo tipo de informaciones relacionadas con las prácticas de campo en asignaturas de Ciencias de la Tierra. El portal incorpora una herramienta de autoedición - el GEOCAMP-EDITOR -, una aplicación informática que permite introducir desde cualquier lugar del mundo los textos y figuras que conforman la descripción de un punto o itinerario de interés geológico. A partir de la información proporcionada, se genera un documento con una maquetación propia que puede ser consultado en formato HTML o descargado como PDF y utilizado como guía de campo.GEOCAMP is a website devoted to field activities in Geology. It is a free access web site available for both teachers and students who carry out field exercises as part of their teaching or learning. It is a hypermedia resource containing original teaching materials and several links with all kind of topics related to field exercises in subjects of Earth Sciences. The website includes a desktop publishing tool - the GEOCAMP-EDITOR -, a software application that allows to download from anywhere in the world the text and images that describe a point or route of geological interest. Once the information has been downloaded, a document is automatically generated. This document can be accessed in HTML format or downloaded as a PDF document to be used as a field guide

Borehole image techniques applied to identification of chert and dolomite layers in lacustrine sediments

Geophysical logging tools, particularly ultrasonic acoustic borehole image techniques, are applied on two different wells (CP1 and CP2) to identify and characterize the lacustrine interval (40m) of the Camp dels Ninots maardiatreme infill (Pliocene, Catalan Coastal Ranges). The CP1 well was cored and also geophysical logs and oriented borehole images were acquired. CP2 hole was partially cored but logging (geophysics and borehole images) was fully undertaken. Continuous core recovery in CP1 is compared with oriented images and is further used to identify and characterize highly reflective signals in a section of CP2 borehole that was not cored. These signals are related to silicified zones and belong to discontinuous centimetric chert nodules, while indurated massive carbonates are characterized as intervals of continuous reflectance. Despite opal nodules (chert) can be relatively small, they have a distinctive response in the ultrasonic borehole images.Peer Reviewe

Difusió virtual d'itineraris de camp en ciències de la terra

El portal d'internet GEOCAMP (http://einstein.uab.es/_c_gr_geocamp/geocamp/), d'activitats de camp en Ciències de la Terra permet optimitzar el treball abans, després i durant una excursió. Fins ara aquest ha estat el contingut del recurs virtual. La gran acceptació que ha anat tenint entre els alumnes de la universitat (sobretot dels primers cursos) com en altres entorns (professorat de secundària etc.) ens ha portat a ampliar-ne el seu abast. Així doncs, ens hem plantejat dos objectius. Un primer objectiu ha estat la traducció de la web al castellà i l'anglès. Un segon objectiu ha estat desenvolupar un apartat de propostes d'itineraris de camp concrets. Aquest segon objectiu ha de contribuir a omplir de contingut el recurs web a partir de l'aportació d'itineraris que estem desenvolupant des de dins el projecte però també a partir d'aportacions externes

Competències i habilitats transversals entre geologia i arqueologia prehistòrica

En aquest treball es desenvolupa una proposta concreta per abordar alguns dels objectius pedagògics, com ara la transversalitat, el treball en equip o la necessitat d'incrementar els coneixements pràctics. La perspectiva des de la que s'ha realitzat ha estat la de la col·laboració interdisciplinària entre docents universitaris que treballen en dos àmbits científics ben diferents: geologia i arqueologia prehistòrica.S'ha desenvolupat una eina pedagògica on els estudiants poden desenvolupar habilitats i capacitats com les esmentades a partir del seguiment d'un cas d'estudi concret: la determinació i procedència dels elements petris utilitzats en la construcció del sepulcre megalític de Puigseslloses (Osona). La proposta es basa en el seguiment i la participació dels estudiants en tot el procés de la recerca: el plantejament del problema historicoarqueològic, la definició de les vies d'estudi concretes, el seu desenvolupament, l'obtenció de resultats i la seva discussió interdisciplinària.En este trabajo se desarrolla una propuesta concreta para abordar algunos de los objetivos pedagógicos, como la transversalidad, el trabajo en equipo o la necesidad de incrementar los conocimientos prácticos. La perspectiva desde la que se ha realizado ha sido la de la colaboración interdisciplinaria entre docentes universitarios que trabajan en dos ámbitos científicos bien distintos: Geología y Arqueología Prehistórica. Se ha desarrollado una herramienta pedagógica a través de la cual los estudiantes pueden desarrollar habilidades y capacidades como las mencionadas a partir del seguimiento de un caso de estudio concreto: la determinación y procedencia de los elementos pétreos utilizados en la construcción del sepulcro megalítico de Puigseslloses (Osona). La propuesta se basa en que los estudiantes sigan y participen en todo el proceso de la investigación, desde el planteamiento del problema histórico-arqueológico, la definición de las vías de estudio concretas, su desarrollo y la obtención de resultados, hasta su discusión interdisciplinaria.This study develops a specific proposal for addressing some of the educational goals of the EHEA such as transversality, teamwork and the need to increase practical knowledge. The perspective from which the study was conducted was interdisciplinary cooperation among university professors who work in two quite different fields of science: geology and prehistoric archaeology. A pedagogical tool was developed in which students can develop skills and abilities such as the ones mentioned above by pursuing a specific case study: the description and provenance of stone elements used to build the megalithic sepulchre in Puigseslloses (Osona). The proposal is based on students' following and participating in the entire research process: posing the historical-archaeological problem, defining the specific avenues of study, conducting the study, getting the results and holding an interdisciplinary discussion of these results

Los fósiles : qué son y para qué sirven

Bajo el término fósil, se agrupan gran cantidad de evidencias materiales de la vida en el pasado. Generalmente, de los organismos fosilizados únicamente se conservan las partes duras, esqueléticas, por ser más resistentes a la destrucción. Pero además de los restos de organismos, también son fósiles las evidencias de la actividad orgánica, ya sean cuerpos materiales (huevos, polen, semillas, excrementos, .) o marcas como pisadas, pistas, madrigueras, etc,. Los fósiles nos permiten comprender la vida en el pasado (evolución de las especies, datación de los sedimentos que los contienen, estudios paleoclimáticos, etc.). Son varios los mecanismos que permiten que un organismo (o una de sus partes) fosilice.Under the term fossil we gather a large amount of material evidences of life in the past. Generally only the tough (skeletal) parts of the fossilized organisms are preserved because they are more resistant to destruction. Apart from organisms remains, the evidences of organic activity are also fossils, being material bodies (eggs, pollen, seeds, defecations) or marks such as footprints, tracks, nests etc,. Fossils allow us to understand life in the past (species evolution, datation of the sediments where are found, paleoclimatic studies .). Several mechanisms permit an organism (or its parts) to be fossilized

A new key locality for the Pliocene vertebrate record of Europe : the Camp dels Ninots maar (NE Spain)

A new Pliocene Konservat-Lagerstätte in north-eastern Spain is described here for the first time. It is referred to as Camp dels Ninots. The particular geological conditions of the site, which correspond to lacustrine sedimentation in a maar, made it ideal for the preservation of fossils. At present, five large mammal skeletons in anatomical connection have been recovered: three individuals of Alephis tigneresi, one of Stephanorhinus jeanvireti and one of Tapirus arvernenis, as well as isolated remains. A minimum of five individuals of the chelonian Mauremys leprosa have been recovered, some of them in anatomical connection. The rodent Apodemus atavus, the amphibians cf. Pleurodeles sp., Lissotriton aff. helveticus and Pelophylax cf. perezi and freshwater fishes (Leuciscus ?) complete the vertebrate assemblage uncovered up to the present time. The coexistence of Stephanorhinus jeanvireti and Alephis tigneresi suggests an age of about 3.2Ma for the Camp dels Ninots, near the MN15-MN16 transition. The Camp del Ninots fossil record enables one to extend the biogeographic range of some vertebrate taxa, such as Stephanorhinus jeanvireti, Tapirus arvernensis or Mauremys leprosa to the Iberian Peninsula. Taphonomic evidences of the skeletal remains indicates minimal (if any) weathering. Deposition at the lake bottom seems to have taken place in oxygen depleted layers. In this way, Camp dels Ninots is comparable to other remarkable maar sites such as Messel, the Eocene site situated in Germany