71 research outputs found
Anexo: análisis de un vástago metálico del yacimiento prehistórico de Peña Parda (Laguardia - Álava)
Se presenta el estudio metalográfico de un vastago metálico recuperado en el abrigo de
Peña Parda (Laguardia, Álava), para determinar su composición química, que resulta mayoritariamente cobre
Lithic raw material in the Cantabrian region: Dialectical relationship between flint and quartzite in the Palaeolithic record
The increase, in quantitative and qualitative terms, of research attending to the geological nature of rocks found in archaeological contexts is changing our perspectives about social and economic territories articulated by Palaeolithic societies in the Cantabrian Region. Practically the only raw material researched in a solid geoarchaeological approach in this area is flint. This paper addresses how the near absence of in-depth geoarchaeological research into raw materials other than flint is modifying our perception of the procurement and management mechanism of raw material in the Cantabrian Region during the Palaeolithic.
To consider this matter in depth, we present the bibliographic and quantitative analysis of 30 representative archaeological sites from the Cantabrian Region whose assemblages were described lithologically using basic and primary categories. The state of play depicts a geographic distribution of raw material in the Cantabrian Region where quartzite is associated with the western sector and flint with the east. Interconnected with this axis, there is a chronological tendency that promotes standardisation in the use of flint by Palaeolithic societies following a chronological order, from the older to the more recent periods. This information, and its contextualisation with the new perspectives resulting from the application of the geoarchaeological proposal used to understand flint procurement, allows us to understand the general tendencies of raw material distribution of the region. Especially, we can detect how the absence of geoarchaeological methodologies of other raw materials than flint has modified the perception of the economic and social dynamics articulated around raw material by Palaeolithic people. This bias does not only affect the geographical and chronological axes, emphasising information from the regions and periods where flint is represented, but also promotes the over-interpretation of long-distance procurement, therefore, building up narratives exclusively based on human mobility.
This situation has generated an incomplete and unbalanced picture of the procurement and management strategies followed by Palaeolithic societies because quartzite, the second most-often used lithic raw material, and other raw materials have only been studied using geoarchaeological methods within the last few years. This research finally points to the continuation of in-depth research of quartzite and other raw materials as the next steps to re-interpret the current paradigms about procurement and management of raw material by Palaeolithic societies, and, therefore, modify our perspectives of social and economic territories
Metallic Copper (Cu[0]) Obtained from Cu2+-Rich Acidic Mine Waters by Two Different Reduction Methods: Crystallographic and Geochemical Aspects
The recovery of valuable metals from different types of wastes has become of prime strategic interest given the scarcity of primary critical raw materials at international scale. Implementation of new methods or refinement of classical techniques with modern technological advances is, therefore, an active research field. Mine wastes are of special interest because their high metal concentrations make them environmentally harmful and economically profitable at the same time. In this study, we evaluated two different methods of Cu recovery from extremely acidic mine waters seeping from wastes and abandoned mines in SW Spain. Through a series of different batch experiments, we compared the method efficiency and crystallographic properties of elemental copper (Cu[0]) obtained by reduction of Cu2+ ions by (1) chemical reduction using ascorbic acid at different environmental conditions of pH (1.50–3.95), temperature (25–80 °C) and ascorbic acid concentration (10 mM to 0.1 M), and (2) classical cementation method with scrap iron at pH 1.50 and 25 °C. Our study demonstrates that the precipitation of Cu[0] can take place at pH 3.95 and low AA concentrations (0.1 M), resulting in large (µm-scale), perfectly developed crystals of copper with pseudoprismatic to acicular habit after 24 h of aging, likely through formation of a transient compound consisting in Cu2+-ascorbate and/or cuprite (Cu2O) nanocolloids. Reduction experiments at higher AA concentrations (0.1 M) showed faster precipitation kinetics and resulted in high-purity (>98%) copper suspensions formed by subrounded nanoparticles. The AA method, however, yielded very low recovery rates (15–25%) because of the low pH values considered. The cementation method, which produced tree-like aggregates formed by sub-micron crystals arranged in different directions, proved to be much more efficient (>98% recovery) and cost-effective.This research was funded by the Spanish Ministry of Science and Innovation through grant number CGL2016-74984-R
Geochemistry of the Zn-Pb-Cu-(Ag)-(Au) epithermal deposits from San José (SE Spain)
Versión preprintAbstracts of the 19th Annual V.M. Goldschmidt Conference (2009): "Challenges to our volatile planet". June 21-26 in Davos (Switzerland).The San José Zn-Pb-Cu-(Ag-Au) vein systems, previously described as low-sulfidation [1], are located in the Cabo de Gata Volcanic Field (SE Spain). These deposits comprise mainly base metal bearing sulfide/sulfosalts quartz veins, while disseminated pyrite with small quantities of gold appear in areas of vuggy silica alteration.
Wallrock alteration includes silicification, advanced argillic, argillic and propylitic zones. Very abundant, penetrative, stockwork-like Fe-Al sulfate veins are found in the argillic and advanced argillic alteration, but ore veins do not show a clear relationship with the alteration zone. Mass balance using the isocone method reveals a gradual lixiviation of most of the elements (except silica) in the highly altered volcanic rocks involving a generalized loss of mass and an increase in the content of some metallic elements (Zn, Pb, Cu) in the less altered zones.
Vein sulfides show a similar or slighty heavier sulfur signature (δ34S: 6-12‰) compared to the dominant volcanic signature of the zone (δ34S: 1-7‰[1]), suggesting a magmatic source but with possible incorporation of sea water sulfate via inorganic reduction. Such magamtic input could also be related to the gold mineralization. The barite signature (δ34S: 19-21‰) also supports sea water involvement. Pyrite in silicification shows depleted sulfur (δ34S: 2-6‰) perhaps as product of the disproportionation of magmatic SO2 which produced the acid alteration. Abundant alunite-jarosite has light sulphur (δ34S: 4-10‰), but its abundance and ocurrence rule out a simple supergene origin. Meanwhile, oxygen isotopes in quartz (δ18O: 8-18‰) indicate the likely involvement of magmatic and non-magmatic fluids in ore mineralization.
The field, mineralogical and geochemical data suggest a complex mineralization history in the San José area, with evidence of both low and high sulfidation hydrothermal systems and the involvement of magmatic and seawater fluids.Departamento de Mineralogía y Petrología (Universidad de Granada).
Departamento de Didáctica de las Ciencias Experimentales (Universidad de Granada).
Instituto Andaluz de Ciencias de la Tierra (Universidad de Granada- Centro Superior de Investigaciones Científicas
Quartzite procurement, not only in fluvial deposits: raw material characterisation of the lithic assemblage from Level XXII-R at El Esquilleu, Cantabrian Region, Spain.
The consideration of quartzite as a secondary raw material has relegated in-depth research of this raw material in favour of such other rocks as flint or obsidian. The latter two are the most researched raw materials because of the information derived from their study: long-distance transport of rocks and mobility of people. In contrast, information obtained from research into quartzite generally supported near-site procurement areas mainly related to secondary river deposits. Together with the wide range of rocks called quartzite by archaeologists, this has influenced the poverty of research on the second most-often used raw material during the Palaeolithic. To overcome this narrow perspective, it is necessary to put quartzite in the centre of the debate as a raw material, using an inductive proposal based on geoarchaeological methodologies.
This issue is approached by the application of a geoarchaeological methodology that combines thin section analysis, stereomicroscope observation, and X-ray Fluorescence compositional analysis of the quartzite from Level-XXII-R at El Esquilleu. Potential areas where quartzite could be procured, especially river beaches, are also characterised here. The results show complex mechanisms of quartzite acquisition based on intensive and selective searching, not only in proximate river deposits, but also in more distant fluvial deposits and conglomerate formations. Finally, in combination with techno-typological criteria, complex mechanisms of exploitation are proposed. These depended on each quartzite type, which promoted not only lithological but also technological variability. All these data open new perspectives for the characterisation of the second best represented raw material in Europe, as well as for understanding acquisition mechanisms in fluvial deposits and conglomerate formations
Aplicación de la espectroscopía de infrarrojo para definir zonas de alteración hidrotermal asociadas a yacimientos epitermales del SE de España
Documento original accesible en: http://www.ehu.eus/sem/macla_pdf/macla7/macla7_104.pdfSe ha realizado un estudio de las alteraciones asociadas a tres depósitos epitermales del Cinturón Volcánico del SE de España: San José, Rodalquilar y Carboneras.Universidad de Granada. Departamento de Mineralogía y Petrologí
Suelos de habitación - suelos de corrales: los casos de Atxoste y Los Husos
[ES] La secuencia estratigráfica de un yacimiento arqueológico responde a dos variables relacionables, aportaciones naturales y actividades antrópicas: la conjunción de analíticas propias de la arqueología y la geología permite descifrar los caracteres de dicha sedimentación y reconocer su origen. Se han aplicado exámenes sedimentológicos y químicos a los yacimientos de Atxoste y Los Husos: por sus tipologías son representativos de la dinámica cultural habida a lo largo del
Holoceno y sirven en la comprensión de la formación de yacimientos arqueológicos. Ligeros elementos constructivos y la distribución de los items arqueológicos han permitido, además, delomitar una cabaña adosada al abrigo en Atxoste y los cierres de un corral en el covacho de Los Husos.[EN] The stratigraphic sequence of an archaeological site responds to two related
variables, natural and anthropic contributions: archaeological and geological analyses together
allow us to decipher the features of this sedimentation and recognize its origin. Sedimentological and chemical analyses have been applied to the sites of Atxoste and Los Husos: due to their typologies they are representative of the cultural dynamics going on through the Holocene and they are useful to understand archaeological site formation. Light constructive elements along with the distribution of archaeological items has also allowed to delimit a hut attached to the rock
shelter of Atxoste and the closing of a corral at the cave of Los Husos
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
Quartzite procurement in conglomerates and deposits:Geoarchaeological characterization of potential catchmentareas in the central part of the Cantabrian Region, Spain
Raw material characterization in Paleolithic archaeology has widened our knowledge of Middle Paleolithic societies. Procurement of raw material, specifically flint, has allowed the tracing of the mobility of both stones and people, as well as selective processes to obtain specific types or even extraction activities. The analysis of quartzite has also developed in recent years, providing an opportunity to better understand prehistoric societies. This study characterizes the procurement strategies implemented by Middle Paleolithic people in the mountainous region of the Picos de Europa. To this end, we present a comprehensive characterization of potential catchment areas: massive outcrops, conglomerates, and river deposits. The exploitation of quartzite at the sites of El Habario and El Arteu allows us to understand the territorial management of this mountainous area through the combination of selective processes and mobility mechanisms in lower and middle altitudes. These perspectives enable us to view the mountainous region not as a barrier but as an environmental mosaic managed by Middle Paleolithic groups. This study shows strategies that bring together direct and embedded procurement based on both intensive and extensive searches. These discourses are more closely related to the daily life of people than those only considering the mobility of people and objects.Education Department of the Government of the Basque Country, Grant/Award Number: POS_2018_1_002; The Spanish Ministry of Science Project, Grant/Award Number: HAR2017-82493-C3-1-P; The Consolidated Research Group in Prehistory of the Basque Country University, Grant/Award Number: IT-1223-1
Alteración hidrotermal en el depósito epitermal de San José (Almería): quimismo y mineralogía
Artículo original publicado en: http://www.ehu.eus/sem/macla_pdf/macla9/macla9_89.pdfLas mineralizaciones de San José se
encuentran localizadas en la provincia
volcánica del SE de España, dentro del
cinturón volcánico de edad Neógena que
se extiende desde Cabo de Gata hasta
Cartagena. En el siguiente trabajo se hace una caracterización mineralógica de la alteración hidrotermal.Departamento de Mineralogía y Petrología (Universidad de Granada)Departamento de Didáctica de las Ciencias Experimentales (Universidad de Granada)Este trabajo se ha desarrollado en el marco del Proyecto de Excelencia RNM736 “Recursos Minerales y Medio Ambiente: Aplicaciones de los Analizadores Espectroscópicos Portátiles de Infrarrojos y Fluorescencia (PIMA y PXRFA)”, de la Junta de Andalucía
- …