When crystals become dust: Speleothem degradation processes in Praileaitz I Cave (Northern Spain)

Within the Praileaitz cave there are evident signs of deterioration of different types and generations, affecting both the host rock and the speleothems. The supports of many of the paintings, specifically the drapes, are in a clear state of deterioration due to disintegration of the texture of the speleothem, resulting from selective dissolution of the crystals and the creation of intercrystalline porosity. To analyse and study the different types of degradation and their causes, we gathered a total of 14 samples of speleothems and rock throughout the cave. The speleothems sampled are of different types and come from different growth phases. In order to monitor the parameters that may be causing the pathologies of degradation, a protocol was drawn up for measuring the environmental parameters and the condensation water and drip water in the cave. To analyse the water from the cave, samples were taken at four representative drip points in the cave and from condensation water.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Redefining shared symbolic networks during the Gravettian in Western Europe: New data from the rock art findings in Aitzbitarte caves (Northern Spain)

Abstract: The renewal of the archaeological record, mainly through the discovery of unpublished sites, provides information that sometimes qualifies or even reformulates previous approaches. One of the latter cases is represented by the three new decorated caves found in 2015 in Aitzbitarte Hill. Their exhaustive study shows the presence of engraved animals, mainly bison, with formal characteristics unknown so far in the Palaeolithic art of the northern Iberian Peninsula. However, parallels are located in caves in southern France such as Gargas, Cussac, Roucadour or Cosquer. All of them share very specific graphic conventions that correspond to human occupations assigned basically to the Gravettian cultural complex. The new discovery implies the need to reformulate the iconographic Exchange networks currently accepted, as well as their correspondence with other elements of the material culture at the same sites. Thus, we have carried out a multiproxy approach based in statistical analysis. The updated data reveals a greater complexity in artistic expression during the Gravettian that had not been considered so far, and also challenges the traditional isolation that had been granted to Cantabrian symbolic expressions during pre-Magdalenian times.The project "Before art: social investment in symbolic expressions during the Upper Palaeolithic in the Iberian Peninsula” (PID2019-107262GB-I00) was funded by the Ministerio de Ciencia, Innovación y Universidades (Spain), PI: Diego Garate. I. Intxaurbe’s PhD research is funded by a grant for the training of research personnel PIF 2019) at the University of the Basque Country (UPV/EHU). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Tracer test in the vadose zone of Praileaitz Cave (Deba, Guipúzcoa). Application for protection of karstic cavities

Se ha realizado un ensayo de trazador en la zona no saturada de la Cueva de Praileaitz (Bajo Deba, Guipúzcoa) para ayudar a la delimitación del área de protección de la cavidad. Dicho ensayo se ha efectuado con 14.000 L de agua desionizada y una masa de 500 gr de LiCl. El trazador analizado (Li+) ha permitido deducir un tránsito de entre 18 y 19 horas desde el momento de la inyección. Esta primera detección corresponde a una ve locidad de flujo no saturado de entre 4-5 m/h. La concentración máxima al canzada de litio fue de 11’28 µg/L.A tracer test has been performed in the vadose zone of the Cave of Praileaitz (Bajo Deba, Guipúzcoa) for helping in the delimitation of its protection area.The test was done with 14.000 L of deionized water and a mass of 500 gr of LiCl. The detection of the tracer substance (Li+) has allowed deducing a transit time between 18 and 19 hours since the injection. This first detection corresponds to a non-saturated flow between 4-5 m/h. The maximum lithium concentration was 11’28 µg/L

Reconstructing the sedimentary history of Lezetxiki II cave (Basque Country, northern Iberian Peninsula) using micromorphological analysis

Micromorphological analysis is an invaluable research tool for reconstructing detailed depositional and post-depositional processes of cave infill sequences and for providing paleoenvironmental insight. In this work, we present the results of a micromorphological and mineralogical study of the sedimentary sequence at the Lezetxiki II cave (northern Iberian Peninsula). The cave forms part of the Lezetxiki archaeological complex which has yielded early Middle Palaeolithic tools and archaic human remains. We have identified three main clastic sedimentary processes as being significant at Lezetxiki II: 1) fluviokarst or runoff processes, which are characterised by yellow sandy illite-rich microfacies; 2) infiltration processes, which produce a massive red silty-clay vermiculite-rich microfacies; and 3) inwash processes, which generate a reworked illite and vermiculite rich silty sand microfacies. The most common post-depositional processes observed are calcite precipitation infilling pore spaces, and compression structures derived from specific vertical loading events. In order to improve the chronological framework of the sedimentary sequence at Lezetxiki II, we have revised previous radiometric and relative dating results from faunal and archaeological remains and have dated the lowermost stratigraphic level using single-grain thermally-transferred optically-stimulated luminescence dating. Sedimentation at the Lezetxiki II cave started during Marine Isotope Stage (MIS) 7 through fluviokarst processes. We interpreted that runoff prevailed during MIS 6, while soil infiltration processes became more significant towards the MIS 5 optimum. Gradually, inwash processes prevailed over infiltration until the end of the interglacial phase. During the following glacial phases, runoff and erosion dominated but were subsequently replaced by inwash processes during MIS 1.PALEOGATE project, funded by the Spanish Ministry of Economy and Competitiveness (HAR2014-53536-P) as well as the US14/16 project funded by the University of the Basque Country and Basque Coast Geopark, and Basque Government (IT1029-16-GBV6). We would also like to thank Tim Nicholson for his work in translating and editing different versions of the English text. Additional financial support for this research was provided by Australian Research Council (ARC) Future Fellowship project FT130100195, ARC Discovery Early Career Researcher Award DE16010074

Mammalian turnover as an indicator of climatic and anthropogenic landscape modification: A new Meghalayan record (Late Holocene) in northern Iberia

The Punta Lucero III cave is a natural trap where abundant vertebrate remains were accumulated during the Meghalayan (Late Holocene). To better understand the paleoenvironmental conditions in which this record was accumulated, the micromammal assemblage, comprising a minimum number of 1396 individuals belonging to 19 taxa, was studied using the Mutual Ecogeographic Range and the Habitat Weighting Method. Throughout ~2600 years, the micromammal community's quick turnover reflected a shift from patchy forests and humid meadows to open, shrubbier grasslands. The Late Holocene Thermal Maximum's humid and mild climatic conditions underwent a cooling and aridification phase, coeval with the Iron Age Cold Epoch. These concluded in a slight temperature rising, coeval with the Roman Warm Period. Macromammals experienced a shift from wild populations to domestic herds. Therefore, this work discusses a broader context for this mammalian turnover from a human cultural perspective.AB.M-A. developed part of this research as part of the ERC Consolidator Grant (SUBSILIENCE ref. 818299). We thank J.A. Delgado for his technical work on studying macromammal assemblage. Financial support was provided by the Bilbao Port Authority (Autoridad Portuaria de Bilbao) within the project “Estabilizaci´on del sector occidental de la Cantera de Punta Lucero en el Puerto de Bilbao”. We are also grateful to Juan Manuel López-García and the anonymous reviewer for their suggestions and comments that strongly improved the manuscript

Unravelling the skills and motivations of Magdalenian artists in the depths of Atxurra Cave (Northern Spain)

Atxurra cave has a decorated assemblage composed of more than a hundred engraved animal depictions. All of them are located in deep parts of the cave and most of them are hidden in raised areas, away from the main path. The main sector is the “Ledge of the Horses”, located at 330 m from the entrance of the cave. It is a space of 12 m long and 1.5 m wide, elevated 4 m above the cave floor. This area includes almost fifty engraved and painted animals accompanied by a dozen flint tools, three fireplaces, and around one hundred charcoal fragments from torches. This extraordinary archaeological record allows us to value the complexity of the artistic production inside the caves during the Upper Palaeolithic. Our study has confirmed that there is planning prior to artistic production, both in terms of the iconographic aspects (themes, techniques, formats), its location (visibility, capacity), and the lighting systems. Furthermore, the data indicates the panel was decorated to be seen by third parties from different positions and was expressly illuminated for this purpose. This evidence supports the role of rock art as a visual communication system in Upper Palaeolithic societies.The authors wish to thank the Cultural Heritage Service of the Diputación Foral de Bizkaia for funding the 4-year multidisciplinary study project (2016–2020) “Study of rock art in Atxurra cave” directed by Dr Diego Garate. The present study has been carried out within the framework of the research project "Before art: social investment in symbolic expressions during the Upper Palaeolithic in the Iberian Peninsula” (PID2019-107262GB-I00), PI: Diego Garate, funded by the Ministerio de Ciencia, Innovación y Universidades (Spain), the research projet “Scientific virtual reality for the study and dissemination of the scenarios of artistic creation in Palaeolithic caves (RealCaveART)” (PDC2022-133124-I00), PI: Diego Garate, funded by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTR, and the research project “Creation and perception in Anatomically Modern Humans: analysis of the biological, cognitive and social skills linked to the production of Paleolithic art (ArtMindHuman)” (PID2021-125166OB-I00), PI: Olivia Rivero, funded by the Ministerio de Ciencia, Innovación y Universidades (Spain). I. Intxaurbe’s PhD research is funded by a grant for the training of research personnel (PIF 2019) at the University of the Basque Country (UPV/EHU). M.A. Median-Alcaide developpes lighting system analyses inside the framework of her “A-Light” project of the HORIZON-MSCA-2021-PF-01-01 (101066376)

Multi-level alkerdi-zelaieta cave system (Urdazubi/Urdax, Navarre): Base-level incision versus (re)sedimentation

Resumen: El sistema kárstico de Alkerdi-Zelaieta tiene un desarrollo de más de 5878 m. En él se engloban distintas cuevas que están genéticamente unidas, pero separadas por la colmatación de las galerías por sedimentos o colapsos. En todo caso, la organización de las galerías formadas en condiciones freáticas indica una mínima disposición de 6 niveles de cuevas, que se han formado en un contexto general de bajada del nivel freático. La formación de cada nivel de cueva está relacionada con procesos paragenéticos, que se deben a un incremento de la carga sedimentaria respecto al caudal hídrico. La variación en el aporte sedimentario se relaciona con cambios climáticos, de forma que cada vez que se repiten las condiciones climáticas propicias se produciría el aumento en la disponibilidad sedimentaria, y con ello, el desarrollo de niveles de cueva en el sistema kárstico. El área fuente de los sedimentos se localiza fundamentalmente en materiales paleozoicos y triásicos del entorno. En este sentido, una vez un nivel de cueva pasa a estar en condiciones vadosas, el sedimento depositado en ella comienza a erosionarse y redepositarse en el nivel inferior que se está formando, reciclándose una y otra vez hasta salir del sistema.Abstract: The Alkerdi-Zelaieta cave system is longer than 5878 m. It is composed by genetically connected caves, which are currently separated by sedimentary filling or collapses. Nevertheless, the disposition of the different subhorizontal passages formed under phreatic conditions shows at least 6 cave-levels, which have been developed in a widespread base-level falling context. The speleogenesis of each cave-level is due to paragenesis, given by an increment on sediment input regarding the stream flow. Changes in sediment input rates are due to climatic changes. Therefore each time that those climatic conditions were reproduced, cave-levels would have been formed. The origin of the sediments are from Paleozoic and Triassic formations of the area. As such, using the meandering conduits that connect different cave-levels, sediments that filled the abandoned galleries were removed and deposited in a lower cave-level that was forming at the moment, being recycled repetitively until they leave the cave-system

AEQUA Field-Guide Series, Vol. 5

Entre los días 1-5 de julio 2019 se celebró en Bilbao la XV Reunión Nacional de Cuaternario. Este congreso de la Asociación Española para el Estudio del Cuaternario (AEQUA) fue organizado localmente por la Unidad de Formación e Investigación en Cuaternario de la UPV/EHU y, entre sus distintas actividades,incluyó 2 salidas de campo. Una primera salida intra-reunión denominada “Historia ambiental de la Ría de Bilbao y su registro sedimentario” tuvo lugar el martes 2 de julio por la tarde, y a través de 4 paradas a lo largo del estuario analizó sus registros sedimentarios holoceno y antropoceno. Una segunda salida post-reunión titulada “El Cuaternario en el Geoparque de la Costa Vasca” se realizó durante el viernes 5 de julio, en la que siguiendo 8 paradas a lo largo del territorio del geoparque se expusieron sus registros geológico, antropológico y prehistórico más significativos.Las entidades colaboradoras de la XV Reunión Nacional de Cuaternario han sido Aranzadi Zientzia Elkartea, Arkeologi Museoa, BC3-Basque Centre for Climate Change, Beta Analytic, Eusko Jaurlaritza-Gobierno Vasco, Geogarapen-Asociación para la Gestión del Geoparque de la Costa Vasca, Sociedad Geológica de España, Sociedad Española de Geomorfología y Universidad del País Vasco/Euskal Herriko Unibertsitatea. Este trabajo ha sido apoyado por los proyectos Antropicosta-2 (RTI2018-095678-B-C21, MCIU/AEI/FEDER, UE) y Harea-Grupo de Investigación en Geología Litoral (IT976-16). Contribución nº 52 de la Unidad de Investigación Geo-Q Zentroa (Laboratorio Joaquín Gómez de Llarena)

Palaeolithic rock art in Alkerdi 2 cave (Urdazubi/Urdax, Navarra)

En el marco del proyecto de «Caracterización del macizo y sistema kárstico de Alkerdi,de la cueva de Alkerdi y de su entorno de protección», se procede a la exploración de la cavidad de Alkerdi 2. Las labores coordinadas han permitido identificar un conjunto de arte parietal asociado a evidencias arqueológicas en superficie. El estilo de las grafías animales grabadas apunta hacia una atribución Gravetiense para la presencia humana. La datación por radiocarbono de uno de los motivos parietales y de un carbón procedente del contexto arqueológico, lo corroboran. Se trata así de la segunda cavidad decorada durante el Paleolítico en Navarra y la muestra artística más antigua de la Comunidad Foral.Within the framework of the characterization project of the massif and karst system of Alkerdi, the Alkerdi cave and its protective environment, the Alkerdi 2 cavity was explored. The coordinated work has made it possible to identify a set of parietal art associated with archaeological evidence on the surface. The style of the engraved animal points towards a Gravettian attribution for human presence. Radiocarbon dating of one of the parietal motifs and a charcoal from the archaeological context corroborate this idea. This is the second cavity decorated during the Paleolithic in Navarre and the oldest artistic remain in the Autonomous Community