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The Doñana National Park is a Biosphere Reserve located within the estuary of the Guadalquivir River (SW Spain). It is mainly composed of extensive fluvio-tidal marshes partially protected by an elongated sandy spit. Three phases have been distinguished in the late Holocene evolution of this spit based on textural, geochemical, palaeontological and, chronological data recorded in a long core (31 m). Phase 1 (890 BCE-218 BCE) is characterized by the alternation of lagoonal silty sediments and slightly polluted marsh deposits, the latter with contamination from thousand-year-old mining. Phase 2 (218 BCE-90 CE) is characterized by several historical tsunamis, which caused the erosion of previous dune systems and the deposit of these sandy sediments on the adjacent bottom of the lagoon. Phase 3 (90 CE-Present) includes a regressive sequence (lagoonal bottom-marsh-dune system), with the pollution of lagoonal sediments due to Roman mining activities.

Portuguese museums and private collectors gather a variety of Italian glazed terracotta sculptures attributed to the della Robbia workshop, particularly active between the 15th and 16th centuries. Compositional studies of the paste using INAA, PGAA and XRD and enamel using PIXE, and luminescence protocols, were used as a tool to ascertain the attribution of the sculptures to della Robbia workshop. Geochemical and mineralogical patterns were defined enabling to express the production recipe. The luminescence ages were found to be between 1380 and 1640 in some cases with high uncertainties. The compositions of the blue glazes were proved to be similar to other measured on della Robbia sculptures from French and Italian collections based on cobalt pigments. Arsenic behaviour, which is associated to cobalt in most cobalt-minerals, is rather peculiar, as it was already found in other della Robbia sculptures enabling a chronological framework, pointing to a production after 1520. Based on the results, most of the analysed sculptures implies a della Robbia production, and only a few point to a composition and chronology not related with that workshop. Fundação para a Ciência e a Tecnologia support through the UID/Multi/04349/2013 and PTDC/HIS/HEC/116742/2010 projects; H2020 CHARISMA funded (Grant Agreement no. 228330) project at Budapest Neutron Center; FB, MNAA, MNAz, FCG, MJ for sampling and field measurements. info:eu-repo/semantics/publishedVersion

A multidisciplinar analysis of sediments collected in diferent environments of the Doñana National Park (Guadalquivir estuary, SW Spain) provides an overview of the textural, mineralogical and physico-chemical parameters that control the distribution of benthic foraminiferal tests in this Biosphere Reserve. These microorganisms are absent in the fne quartzitic sands that constitute the substrate of temporary ponds with brief hydroperiods located in the dune systems and spits, as well as in other ponds with low conductivities or hypersaline conditions located in the inner marshlands or near the Guadalquivir river banks. Dead benthic foraminifera are mainly found on phyllosilicate-rich, silty-clayey substrates. The taphonomic analysis of the main species (Ammonia tepida, Haynesina germanica, Trochammina infata, Entzia macrescens) points to its deposit in situ. Cluster analysis permits to delimitate six foraminiferal assemblages. Cluster II (A. tepida+H. germanica) is the dominant assemblage in the central ponds and the margins of the main channels, while cluster IV (T. infata+E. macrescens) is restricted to some ponds located on the high marsh and cluster VI (Ammonia beccarii+Quinqueloculina spp.) is abundant on external beaches. Tidal fuxes cause the transport of these last marine benthic species and some plaktonic forms both to the inner areas of the estuary and to these beaches. info:eu-repo/semantics/publishedVersion

The genesis and development of calcretes are discussed by using nuclear and related methods of analyses. In the studied calcrete, smectite is the main clay mineral associated with palygorskite. Chemical elements proportions, particularly V, U, Mn, Cu, Ba and REE, indicate a change to more oxidizing conditions and the contribution of bio-mediated processes in the oxalate-carbonate pathway, also confirmed by the presence of needle-fibre calcite. The proposed pathways leading to the studied calcrete development comprise both abiotic and biogenic genesis, emphasizing the polygenetic character due to different agents and processes and the paleoenvironmental trend towards aridification, with a transition between lacustrine and palustrine environments.

Old mine tailings from Northern and Central Portugal were studied in order to perform a radiological and chemical characterization. The evaluation of massic activity of natural radionuclides and concentrations in tailings of polymetallic and Ra/U mines was performed by gamma spectrometry and neutron activation analysis. Iron speciation was carried out by Mossbauer spectroscopy. In polymetallic tailings with physical ore processing (Cumieira and Verdes - exploited for Sn, Nb-Ta) higher contents of Th, 228Ra and 226Ra in the coarser materials occur, probably due to their presence in host rock and ore fragments. In finer tailings, washing may explain the lower 226Ra and 210Pb massic activity. In tailings with physical/chemical ore processing (Covas - exploited for W and Sn) high U contents and a tendency for higher 226Ra and 210Pb massic activity in the fine materials is observed, probably due to their incorporation in nano-sized particles of iron oxides. A high variation of the 210Pb/226Ra ratio occurs in polymetallic tailings; a deficit of 210Pb can be observed particularly in deposits of settling tanks drained from dumps of chemically treated ore. In Ervideira-Mestras tailings (Ra/U exploitation) where no ore process in situ was performed, a near equilibrium between 210Pb and 226Ra occurs. Dose risk assessment was carried out by calculating external outdoor Annual Effective Dose Rate; the dose rates in air due to terrestrial gamma radiation are low for the polymetallic tailings (

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Geochemistry of mudrock units deposited in the sedimentary basin of Algarve (South Portugal) during Mesozoic and Cenozoic depositional cycles were studied, aiming a better knowledge of the evolution of the Basin. Two types of mudrock units were found: (i) silicic and Ca-poor (Cretaceous and Cenozoic), and (ii) calcareous (Middle–Upper Jurassic Ca-rich mudrock units and Upper Triassic to Lower Jurassic Mg-rich redbeds). LILE appear to be controlled by a K-bearing phyllosilicate, which is consistent with the abundant illite in the redbeds. Positive trends of: (i) Sc, Cr, Th, LREE with Al2O3 suggests their incorporation in clay minerals, and (ii) HREE with TiO2, Zr and Hf point to their presence in heavy minerals. The source area of the Algarve mudrock units was dominated by felsic rocks; features typical of a mafic source occur in some Upper Triassic to Lower Jurassic samples. Carboniferous metasediments of the basement were probably the first order source for the Algarve sedimentary basin. A more severe weathering in the Cenozoic and Cretaceous mudrock units occurred, whereas diagenetic enrichment in potassium is observed in the Upper Triassic to Lower Jurassic continental redbeds.

Extrusive carbonatite ash tuff (Tantum) and spatter (Monte Miranda) deposits, and topsoils (incipient and shallow) from both sites of Brava Island (Cape Verde archipelago) were studied by neutron activation analysis, X-ray diffraction and Mossbauer spectroscopy. The ash tuff deposit near Tantum, here reported for the first time, corresponds to an extrusive calciocarbonatite with high W, Th, U and REE contents and a positive Eu anomaly. Similar REE patterns and W concentrations were also found in the spatter deposit of Monte Miranda. Magnetite is the major iron containing phase in both extrusive carbonatite deposits. High W and REE concentrations associated with the presence of calcite prevail in topsoils with extrusive carbonatite influence. In the topsoil developed on extrusive carbonatite ashes, magnetite is well preserved particularly in the coarser fractions probably due to the recent age of the parent material associated with the semi-arid climate of the island; a significant chemical heterogeneity of the whole samples as well as of the different size fractions of these topsoils was found, with an enrichment of Co, Zn, Ga, As, Br, Rb, Ce, and particularly Sb and W in the clay-size fraction, which may be relevant for the study of environmental health issues in Brava Island.

The elemental content&mdash, mainly trace elements&mdash, of samples from two boreholes (PLN, CM) with evidence of tsunamiites, located in the Do&ntilde, ana National Park (SW Spain), were studied. The geochemical variations of the REE, LILE, HFSE, and other elements (Al, Ti, S, Na, Br, Sc, Co, Cr) were interpreted according to the mineralogy present in the samples. The results obtained show the geochemical complexity of the estuarine paleoenvironments, in this case with the existence of three Holocene-age tsunamigenic deposits (around 4.25, 3.56 and 2.2&ndash, 2 kyr BP). The statistical analysis of the samples&rsquo, geochemistry, by means of linear correlation and factor analysis, made it possible to differentiate two associations. The first is representative of an inherited mineralogy (REE-Y-Rb-Sr-Cs-Th-U-Hf-Al-Ti-Co-Cr-Sc), the second includes elements (Br-Na) linked to mineral formation under evaporite conditions (halite). The trace element geochemistry of sediments thus becomes an excellent tool to identify tsunamiites in the studied zone, especially those elements that are clear proxies for marine incursions (Na, Br, Sr) and high energy events (Hf, Ti). The parent area of the provenance of the materials is mainly of felsic composition.

An interdisciplinary approach comprising archaeological, chemical, mineralogical, and luminescence data was applied to a better understanding of the fill dynamic and chronologies of a calcite-rich negative archaeological feature from Southern Portugal. This work aims to contribute to the assessment of the human involvement in the backfilling actions of a negative archaeological feature from a Chalcolithic site, thus better defining the moments of its destruction and/or abandonment. There are well-known limitations of luminescence dating of calcite-rich materials, particularly in the dose rate determination. In this work, a proposal of two innovative protocols to determine the dose rate of calcite-rich contexts is discussed. A clear improvement of the dose rate estimation was obtained by using the "radionuclide weighed" protocol. The comprehensive used methodologies enabled to define the infill phases and the sources of the infill materials. The luminescence profiling studies were also useful to describe the infill processes, highlighting their discontinuity and pointing to different deposition rates. The luminescence ages obtained, when using the "radionuclide weighed" protocol proposed in this work, are closer to the archaeological evidence of a Chalcolithic occupation. FCT (Portuguese Science and Technology Foundation)Portuguese Foundation for Science and Technology [UID/Multi/04349/2013, BL 36/2016_IST-ID, UID/GEO/04035/2013, PTDC-CS/ANT/104333/2008] FCTPortuguese Foundation for Science and Technology [SFRH/BD/62396/2009, SFRH/BPD/114986/2016] info:eu-repo/semantics/publishedVersion

Topsoils of pyroclastic materials collected on two volcanic conduits of the Cha das Caldeiras caldera of the oceanic Fogo Island (Cape Verde) were studied. Significant positive Eu anomalies were found in both pre-historic and historic cones, which together with the presence of jarosite, may be considered hydrothermal signatures that survived in this surficial semi-arid environment.

Topsoils developed on different lithologies of all the geological units of the volcanic Brava Island (Cape Verde archipelago) were studied by neutron activation analysis and Mossbauer spectroscopy. Sampling was performed according to the recommendations of the IGCP 259 (“International Geochemical Mapping”). Significant chemical contents variations were found even within the same volcano-stratigraphic unit, inherited from the parent rock composition under the semi-arid climate of the island. The chemical heterogeneity of topsoils within the same geological unit, particularly in the Upper Unit, was evidenced by a multivariate statistical analysis. Some differences found can be related with the geographical location/underlying basement. High contents of Mn, Co, Ga, Ba, La, Ce, Nd, Sm, Eu, Tb, Ta, W, Th and U were observed in soils related to carbonatites and phonolites. REE and W can be used to trace outcrops of extrusive carbonatites. In general iron is strongly oxidized occurring in the silicates structure as well as in hematite, oxidized magnetite and maghemite. The global iron oxidation degree, the fraction of Fe 3+ in silicates and the fraction of nanosized oxides, which are higher in topsoils of the older units, may be an indicator of weathering degree. As, Br and Sb contents were also found to increase with weathering. Topsoils developed on extrusive carbonatites are clearly distinguished due to the absence of Fe 2+ in the silicate phases and the remarkable predominance of low oxidized magnetite.

In 2015 an extraordinary hydrometeorological event occurred in the southern Atacama Desert (northern Chile) that resulted in a catastrophic flood in the city of Copiapo. A large volume of detrital sediments was transported downstream, provoking an economic and environmental disaster in the Copiapo Valley, a region dominated by mining activity. Loads of sediment and residues were moved by the flow and deposited throughout the urban area of Copiapo. The current study explores the geochemical features and associated pollution risks of metal(loid)s in sediments collected in different points of the city after the flood event. Results revealed that, despite the high natural concentration of elements due to geogenic chemical composition of the area, geoaccumulation of Al, As, Cd, Co, Cu, Hg, Fe, Mn, Ni and Pb showed moderate contamination when compared to the background concentrations of the area. Furthermore, Hg, originating from legacy mining practices, constituted the main environmental risk associated with the flood sediments. Finally, data from this study were compared to other flood events and mining spills; some contaminants in the 2015 flood sediments in Copiapo were higher than some historical mining disasters. This work highlights the potential intersection between anthropogenic activities (mining) and extreme hydrometeorological events (floods) in arid environmental degraded areas.

Intrusive carbonatites from a fluvial valley near Monte Almada (Fogo Island, Cape Verde), corresponding to the oldest unit of the island (≈4.5 Ma) occur under alkaline lavas and tuffs of more recent age in two slopes, with a very steep inclination. Its exposure with the water line fitting led to the weathering of the outcrops, and the materials are currently retained in small terraces with shrubs and trees. The motivation that drives this work was the absence of paleoweathering materials studies of these carbonatites in Fogo Island. Mineralogical and chemical analyses of paleoweathered carbonatites samples with different weathering degrees were performed by means of X-ray diffraction (XRD) and instrumental neutron activation analysis (INAA). The results obtained from fresh rock to near paleosurface samples showed that chemical contents could vary significantly in the fresh rock, particularly the trace elements, including the rare earth elements (REE), as well as in the size fractions. Besides calcite, pyroxenes and phyllosilicates, traces of anatase and K-feldspars also occur in the

El análisis multidisciplinar de un perfil descubierto por las tormentas invernales en el litoral del Parque Nacional de Doñana ha permitido reconstruir la evolución de su sector occidental durante el Holoceno superior. Se han definido 3 fases que reflejan el paso desde una marisma de aguas salobres (FA-1) a una laguna de aguas dulces transformada en turbera (FA-2), para finalizar con el depósito de cordones dunares (FA-3)., The multidisciplinary analysis of a profile discovered by the winter storms on the coast of the Doñana National Park has allowed us to reconstruct the evolution of its western sector during the Late Holocene. Three phases have been defined, which reflect the transition from a brackish water marsh (FA-1) to a freshwater lagoon transformed into peat bog (FA-2), to end with the deposit of dune systems (FA-3).

A first detailed study of phosphogypsum (PG) from a stockpile in Barreiro (Portugal) was performed aiming for a better characterization of this industrial waste deposit, considering its enhanced content in natural radionuclides and toxic metals, making it a potential contamination source to the Tejo estuary. Whole samples and aggregates of these wastes resulting from phosphate industries were analysed by neutron activation, gamma-spectrometry, X-ray diffraction and scanning electron microscopy. This work clearly shows that a significant chemical heterogeneity in the PG occurs due to the existence of aggregates with different compositions randomly distributed. Among these aggregates, the dark grey ones have high concentrations of Sc, Cr, Zn, Ga, Ba, REE, Ta, W, Th and U and the highest concentrations of 226Ra and 210Pb. The separation of these dark aggregates prior to any application of the PG would lead to a safer reuse of these wastes. The chemical patterns, including the REE distribution with a significant negative Ce anomaly, found in PG, are certainly related with the geochemical signatures of the phosphate rocks used as raw material. This PG stockpile may play a significant role as a radioactive source in the Tejo estuarine environment.

AMS radiocarbon and OSL dating, and profiling were used to directly delimit periods of variscite production at Pico Centeno Mine 2. These results were integrated with analysis of other well-dated periods of variscite production to establish an Iberian-wide chronological framework. Variscite production at Pico Centeno Mine 2 began at ~ 5200 BC, coincident with alpine jade production or Casa Montero Iberian flint production. Variscite was only used occasionally, together with other greenstones, during the 5th and 6th millennia BC. During the 4th millennium BC, variscite use began to increase to its apogee in the first half of 3rd millennium BC when it appeared in nearly every Iberian burial site. This increase in variscite production and use coincided with decline in the popularity of alpine jade. By the end of the 3rd millennium BC, new resources began to be valued such as Asian and African Ivory, Baltic and Sicilian amber, and copper-based metal products. The variscite cycle thus started with the decline of jade in the 5th–4th millennium BC, and ended with the appearance of copper, ivory and extra-peninsular amber by the end of the 3rd millennium BC.

Portuguese occidental and southern coasts comprise the most important ceramic productions centres in the Lusitania province of Roman epoch. The main purpose of this work is to present an appraisal on the compositional patterns of 14 Lusitanian ceramic workshops, by reconstructing their life cycle from the procurement and processing of the raw materials, to trace provenance, trades and their impact in the Roman world. The chemical composition of ceramics and clays was obtained by instrumental neutron activation analysis and mineralogy by X-ray diffraction. The definition of reference groups relied on the use of chemometric techniques for data structure analysis, coupled with geochemical considerations. Results allowed differentiating between and within workshops by establishing geochemical fingerprints.

Barks from Prosopis juliflora (acacia) were collected in 12 sites of different geological contexts over the volcanic Fogo Island (Cape Verde). Elemental contents of Ba, Br, Co, Cr, Fe, K, Na, Zn and some rare earth elements (REE)-La, Ce, Sm, Eu, Tb, Yb, and Lu, were obtained for biological samples and topsoils by using k 0-standardized and comparative method of instrumental neutron activation analysis (INAA), aiming the evaluation of chemical elements uptake by acacia bark. This first biomonitoring study of Fogo Island showed that, in general, significant accumulations of trace elements present in high amounts in these soils occur. This can be partially explained by the semi-arid climate with a consequent bioavailability of chemical elements when rain drops fall in this non-polluted environment. REE enrichment factors (EFs) increase with the decrease of ionic radius. Heavy REE (HREE) are significantly enriched in bark, which agrees with their release after the primary minerals breakdown and the formation of more soluble compounds than the other REE, and uptake by plants. Among the potential harmful chemical elements, Cr appears to be partially retained in nanoparticles of iron oxides. The high EFs found in tree barks of Fogo Island are certainly of geogenic origin rather than anthropogenic input since industry and the use of fertilizers is scarce.

Instrumental neutron activation analysis of small flakes from the same flint fragment of archeological artefacts from Palaeolithic sites (''Abrigo de la Quebrada'', ''Cova de les Cendres'' and ''Cova Negra''), and geological sources (Chelva, Valencia, and Alcoi, Alicante) from the eastern Spain, was performed. The chemical contents of 27 elements were obtained. Ga, Ce, Nd, Yb, Zr and Hf were discarded due to high variations within the same fragment. The identification of chemical fingerprints within hetero- geneous flint fragments was able to differentiate flint types and variants (''Domeno'' and ''Serreta''), contributing to provenance and human mobility in ancient times.

A set of beads was studied to investigate their nature. They come from a funerary feature used for the secondary deposition of cremated remains of more than a hundred individuals. The pit is located in the centre of Perdigoes (Evora, Portugal) ditched enclosures (Valera et al., 2014a) and is dated from the third quarter of the 3rd millennium BC. The beads were also burned and were part of the funerary votive assemblages, also composed by arrowheads ivory figurines, marble idols and pots, phalanx idols, copper awls, Pecten shells and pottery sherds. These beads have a diameter between 5 and 10.5 mm, with a central perforation up to 5 mm and maximum thickness of 3 mm, they are dark grey or black and were of unknown nature. This study shows that these beads were made from shells and submitted to heating processes. The study demonstrates the ability of neutron and X-ray methods to determine the nature of the material even being very calcium rich. Chemical results show that they have high contents of calcium, and that the surface is more contaminated with soil particles due to high Si, Fe and K contents, and phosphorous was found in higher proportion, certainly originated from the bones. FTIR patterns show that the major part of the beads is calcium carbonate crystallized in calcite form, contaminated with silicates and calcium phosphate, pointing to shells as raw materials. The ToF-ND results also indicate the crystal lattice structure of calcite, and aragonite, a polymorph formed in the biomineralisation process of shells, was not detected, indicating a total phase transformation to calcite probably due to heating processes during funerary practices. The SEM-EDS results confirm the shell nature of beads. The results were of wider significance for the archaeological discussion, especially deciphering the nature of the beads, contributing to the debate of interaction in the Chalcolithic of Southern Iberia.

Estuaries are very sensitive ecosystems to human activities and the natural evolution of their drainage basins located upstream. Pollution derived from human activities, such as historical mining or recent industrial wastes, can significantly affect their environmental quality. This paper analyzes the silver and copper contents of four cores extracted in two estuaries of SW Spain. Its chronology and vertical evolution allow to differentiate the effects of several pollution episodes (natural, Roman, 19th-20th centuries) on its different sedimentary environments in the last 6 million years. Possible future applications are included in the fields of environmental management or even education.

During the late Neogene, the Mediterranean Sea was connected with the Atlantic Ocean by two straits: the northern Betic Strait and the southern Rifian Strait. In this paper, we analyze the main palaeoenviromental changes produced in the western sector of the Betic Strait during the late Tortonian–middle Messinian (7.4–6 Ma). The temporal evolution and statistical analysis of benthic foraminiferal assemblages both in cores and surface sections of the western Guadalquivir Basin (SW Spain) allow drawing an initial important deepening from the late Tortonian calcarenite coastal areas to the well oxygenated, upper slope palaeoenvironments of the latest Tortonian to early Messinian, with a latest Tortonian condensed horizon composed by glauconitic silts deposited in the middle-outer shelf. The lower Messinian silts and clays (7.2–6.3 Ma) were deposited in a upper slope scenario, with a small oxygen depletion at 6.48 Ma. The 6.3–6.2 Ma interval was characterized by an important sea level drop and the presence of low oxygenated, outer shelf palaeoenvironments in this area, coinciding with a global glaciation. Prior to the Messinian Salinity Crisis (5.97–5.33 Ma), the upper slope palaeoenvironments were initially re-established (∼6.2–6.1 Ma) and finally a new regressive period (∼6 Ma) preceded Messinian Salinity Crisis.

In the last few decades, the rapid technological evolution has led to a growing generation of waste electrical and electronic equipment (WEEE). Not rarely, it has been exported from industrialized to developing countries, where it represents a secondary source of valuable materials such as gold, copper, and silver. The recycling of WEEE is often carried out without any environmental and health protection. This paper reviews recent literature dealing with the informal treatment of WEEE in developing regions, gathering and analyzing data on concentration of both inorganic and organic pollutants in the environment. Open burning practices are revealed as most polluting ‘technology’, followed by mechanical treatment and leaching. Significant levels of pollutants have been detected in human bodies, both children and adults, working in or living in areas with informal WEEE treatment.

A detailed survey of the most clay-rich rock units of the Meso-Cenozoic geological section exposed in the Algarve Basin (South Portugal) was performed and data were analysed for the grain-size distribution and mineralogy (whole rock and clay fraction), aimed at a compositional study of the clay-rich sediments and their depositional environment. Granulometry was obtained using wet sieving and laser diffraction by attenuation of X-rays, and the mineralogical study was carried out by X-ray diffraction.Most clay-rich rock units of the Algarve are classified as silty clays and clayey silts, and only a minority is coarser. The mineralogical study enabled us to define two main types of clays: (1) noncalcareous clays, consisting largely of quartz and clay minerals, with goethite as the typical Fe-rich phase (sediments of Carboniferous, Neogene and Quaternary age and Cretaceous siliciclastic clays); and (2) calcareous clays, which can be calcite-rich clays (Middle and Upper Jurassic) or dolomiterich clays (Triassic and Lower Jurassic), the latter typically containing hematite as an accessory phase. Plagioclase, K-feldspar, and Ti-oxides are often accessory phases, whereas ankerite, anhydrite, gypsum and opal are rare.In the clay fraction illite generally predominates, resulting probably from weathering of preexisting rocks, as well as the less frequent Fe-chlorite, pointing to incipient chemical alteration under semi-arid climatic conditions. Kaolinite occurs in diverse proportions, being especially abundant in Cretaceous and Cenozoic units; it is mainly related to chemical weathering in continental environments under humid conditions. As the Atlantic Ocean opened during Triassic and the continental environment evolved to a shallow-marine environment with evaporitic conditions, smectite became more expressive, being sometimes accompanied by other Mg-rich phases (chlorite, sepiolite, corrensite and palygorskite). Especially during the Cenozoic the proportion of different phases in the clay mineral association of the sediments reflects the control of tectonic movements and fluctuations in sea level during their deposition.

Artistic and historical examination of high-quality glazed terracotta sculptures displayed in various Portuguese museums point to their production in della Robbia workshop of Florence (Italy). A multitechnique analytical approach is applied for the first time to these sculptures, aiming to confirm their origin. Materials were analyzed using Instrumental Neutron Activation Analysis, Prompt Gamma Activation Analysis and X-ray Diffraction. The compositional results are similar to other della Robbia sculptures, suggesting a common origin for the raw material that was identified as carbonate rich marine origin marly clay. The applied firing temperatures was proved to be around 900 °C. The differences found within each sculpture are explained by the production technique of assembling separate parts to produce these huge sculptures, and the clay pit heterogeneity.

Topsoils developed in different geological formations/ages, and the top layer of the lava flow from the most recent eruption (2014/2015) of Fogo Island (Cape Verde archipelago), were studied. The specific objectives of this work are: i) to estimate the REE contents and patterns in the whole sample of topsoils developed on different geological formations/ages and their correlation with the iron speciation; and ii) to study the top layer of a lava flow from the most recent eruption after two years of exposure. REE contents are in general higher in the topsoils of the pre-caldera than in those developed on the post-caldera formation, particularly the light REE probably due to their incorporation into hematite. Positive Eu anomalies found in recent topsoils suggest the existence of hydrothermal processes with intrusion of hot fluids with higher concentration of Eu2+. In the top layer of the lava flow of the most recent eruption, Fe is incorporated in pyroxenes and iron oxides (magnetite and/or maghemite). This study can be a benchmark for further knowledge of the chemical evolution and weathering rate in semi-arid climate of Fogo Island., The authors would like to thank the financial support by Fundação para a Ciência e a Tecnologia (FCT, Portugal) through the projects UID/GEO/04035/2013 and UID/Multi/04349/2013.

Mineralogical and chemical compositions of residual and sedimentary clays (bulk and A more successful result was the geochemical differentiation of clay types. The weathered schist presents greater enrichment in Cr, whereas the clay fraction of aplite-pegmatites shows enrichment in all the chemical elements studied. The sediments and weathered granites are not easy to differentiate; the best geochemical indicators are U (lower contents in clay-size fraction of sediments) and REE patterns in both bulk and clay-size fraction.

International audience; Soils of the semi-arid area of the El Melah coastal lagoon (NE Tunisia), with a closing evolution dynamic, were studied aiming: (1) the chemical and mineralogical characterization of surface and subsurface layers of soil profiles from locations previously submerged and of soils developed on dunes; (2) to evaluate the dependence on the environment conditions of the geochemical patterns of the soils; and (3) to determine chemical and mineralogical variations with the emersion of the sediments resulting from the decrease in the extent of the area permanently covered by water in the lagoon. The compositional results obtained showed significant differences depending on the environment (littoral plain, old dunes and sandy spit), but soils of the different environmental zones studied do not appear to be significantly polluted as far as trace elements are concerned. Among the elements studied, high element/Sc ratios and variations were found for As, Sb and Zn. Antimony is more concentrated in coarser samples suggesting its adsorption in Fe or Mn oxides coating quartz grain surfaces. Arsenic and zinc may be incorporated into the carbonates structure, as well as adsorbed on, or coprecipitated with, iron oxides. Zinc may also be significantly incorporated in clay minerals. Iron was found to be more oxidized in the cultivated soil from the old dune strand; and more reduced in the sandy spit where ankerite occurs suggesting the reduction of Fe3+ in oxide/hydroxides by microorganisms and incorporation of Fe2+ in carbonates. REE patterns, particularly the HREE/LREE are correlated with carbonates, indicating preferential incorporation of the HREE in carbonates, and of the LREE in clay minerals/ iron oxides. High Ga contents were found in soils and sediments rich in clay minerals/Al, suggesting its incorporation in clay minerals structure. Therefore, Ga may be used as an indicator of the clay minerals proportion in sediments and soils. Carbonates, sulphates, besides Fe and/or Mn oxides and clay minerals, appear to play an important role on the trace elements distribution.

Carbonate-rich archaeological artefacts are difficult to identify and correlate between them and with raw materials of such heterogeneous geological sources, especially when only non-invasive analysis is possible. A novel combination of X-ray and neutron-based non-invasive analysis is implemented and used for the first time to study prehistoric stone idols and vessels, contributing to culture identity, mobility and interaction in the recent Prehistory of Southern Iberia. Elemental composition was obtained by prompt gamma activation analysis (PGAA) and external beam particle-induced x-ray emission (PIXE); homogeneity of the stone artefacts and the presence/absence of internal fractures were obtained by neutron radiography (NR). These atomic and nuclear techniques, simultaneously used for complementary chemical information, have been demonstrated to be of great value as they provide non-destructive compositional information avoiding sample preparation, crucial in so singular and rare objects. The obtained results, especially of PGAA, are very promising and useful in general assessments of provenance. The stone artefacts show signs of both nearby and long-distance procurement, as well as of unknown attribution.

The dune of Oitavos, the underlying paleosol, and Helix sp. gastropod shells found within the paleosol were dated using a combination of radiocarbon and blue optically stimulated luminescence (OSL). The organic component of the paleosol produced a significantly older age (∼20,000 cal BP) than the OSL age measurement (∼15,000 yr), while 14C age measurements on the inorganic component and the gastropods produced ages of ∼35,000 yr and ∼34,000 yr, respectively. Rare-earth element analyses provide evidence that the gastropods incorporate geological carbonate, making them an unreliable indicator of the age of the paleosol. We propose that the 14C age of the small organic component of the paleosol is also likely to be unreliable due to incorporation of residual material. The OSL age measurement of the upper paleosol (∼15,000 yr) is consistent with the age for the base of the dune (∼14,500 yr). The younger OSL age for the top of the dune (∼12,000 yr) suggests that it was built up by at least 2 sand pulses or that there was a remobilization of material at the top during its evolution, prior to consolidation.