Xabier Murelaga

... X. Murelaga (1), H. Astibia (1), JI Baceta (1), Y. Almar (2), B. Beamud (2,3) y JC Larrasoaña (4) ... Las huellas fósiles descritas en esta nota fueron descubiertas por tres de los fir-mantes (JCL; YA y BB), mientras rea-lizaban una campaña de recogida de mues-tras para estudios ...

Three very different records are combined here to reconstruct the evolution of environments in the Cantabrian Region during the Upper Pleistocene, covering ~35.000 years. Two of these records come from Antoliñako Koba (Bizkaia, Spain), an exceptional prehistoric deposit comprising 9 chrono-cultural units (Aurignacian to Epipaleolithic). The palaeoecological signal of small-vertebrate communities and red deer stable-isotope data (δ(13)C and δ(15)N) from this mainland site are contrasted to marine microfaunal evidence (planktonic and benthic foraminifers, ostracods and δ(18)O data) gathered at the southern Bay of Biscay. Many radiocarbon dates for the Antoliña's sequence, made it possible to compare the different proxies among them and with other well-known North-Atlantic records. Cooling and warming events regionally recorded, mostly coincide with the climatic evolution of the Upper Pleistocene in the north hemisphere.

Las Bardenas Reales de Navarra se encuentran en el borde NW de la cuenca terciaria del Ebro. Los sedimentos que podemos encontrar en la mayor parte del área de estudio pertenecen a facies fluvio-palustres de la Formación Tudela. Las localidades fosilíferas estarían incluidas dentro de la Biozona MN2b-MN3 (Biozonas Z-A del Rambliense o Aquitaniense superior-Burdigaliense inferior). En esta área se han encontrado restos fósiles de peces, anfibios, lagartos, anfisbénidos, serpientes, tortugas, cocodrilos, flamencos y los mamíferos que se describen en este trabajo como insectívoros, quirópteros, castores, eomíidos, glíridos, esciúridos, cricétidos, lagomorfos, perisodáctilos y artiodáctilos. The Bardenas Reales of Navarre are located on the NW border of the tertiary Ebro basin. Most of the deposits in the area correspond to fluvio-palustrine facies of the Tudela Formation. The fossiliferous localities probably belong to the Biozones MN2b-MN3 (Biozones Z-A of the lower Ramblian or upper ...

The Pico del Fraile section has more than 200 metre thick and it is located in the youngest rocks of the Tudela Formation (north-western part of the Ebro Basin). Two localities with micromammalian fossil remains are known in this section, PF1 and PF2. In the site of PF1 the micromammal assemblage is composed by Simplomys simplicidens, Peridyromys murinus, Vasseuromys sp., Ligeremys sp. and Lagomorpha indet and in the locality of PF2 by Eumyarion cf. weinfurteri, Megacricetodon cf. primitivus, Democricetodon aff. hispanicus, Spermophilinus cf. besana, Microdyromys cf. legidensis, Galerix sp. and Lagomorpha indet. The more abundant taxa represented in both two localities is the glirid Vasseuromys. According to the micrommal taxa the locality located at the Ramblian (Biozone A) whereas PF2 is lower-midle Aragonian (Biozone C or D). The forms of Vasseuromys sp. present in PF1 and PF2 are clearly distinguishable among themselves and with the rest of the genus species.

Numerous macro- and microvertebrate remains were retrieved from the site of Peña Larga, during the field campaign of 2008. The macromammal assemblage includes 3 bovids, 2 suids, 2 cervids, 2 canids, 2 felids, an equid, and a mustelid. The micromammal one includes 9 rodents, 3 insectivores, a bat, and a lagomorph. The reptiles are represented by 2 lizards and a snake, the amphibians by a frog, and the Aves by 2 paseriforms. During deposition of Level III, the rock shelter was used as a burial site. No human occupation during this period promoted a remarkable accumulation of microvertebrates by birds of prey and other predators. The microvertebrate association suggests a wooded environment and a mostly humid-temperate climate. Peña Larga also has the oldest evidence of animal domestication from the Iberian Peninsula.

ABSTRACT Beachrocks are sedimentary structures derived from the precipitation of carbonates in the intertidal zone. Because of this cementation process, they can involve a significant variety of grain types within their structures. This is the case for beachrock outcrops located in the vicinity of the Nerbioi-Ibaizabal estuary (Getxo, Basque Country), an area highly influenced by industrialization. Concretely, a vertical beachrock outcrop located in Arrigunaga Beach, in the inner part of the mouth of the estuary, was studied using a novel analytical methodology to simplify and understand the heterogeneity of the deposits. First, a granulometric separation was carried out followed by the optical microscopic inspection of the fractions and their Raman spectroscopic analysis, revealing the probable heterogeneity of the main beachrock constituents (carbonates and metallic compounds) in each fraction. The total carbonates (acid–base back titration) and the acid-extractable elements (ICP-MS) were quantified, followed by chemometric analyses (correlation analysis and principal component analysis). The combined use of these conventional techniques was particularly relevant for concluding that although the main elements were Fe, Ca, Mg, Mn, Al, Na and K, the key point lies in their distribution in different particle sizes. Indeed, heavy metals, particularly Fe, were accumulated in the 75–250 μm fraction, in contrast to a higher content of carbonates and Ca in the <75 μm fraction. The fact that heavy metals were more concentrated in the coarser fraction led us to believe that an external income of these elements existed, which is likely to come from industrial wastes. Furthermore, the complementarity of the techniques used corroborated the isolation of cements in the finest fraction. Thus, the analytical methodology proposed here helped in distinguishing anthropogenic elements from those comprising the cements, suggesting that both the trapped materials and the components responsible for the cementation occurred in this temperate latitude.