Geochemical fingerprinting of Roman pottery production from Manta Rota kilns (Southern Portugal)

The Roman site of Manta Rota, located in Algarve region, Portugal, is known from the XIXth century when Estacio da Veiga recovered a few pottery fragments and identified the foundations of Roman structures. References in early XXth century refer to a pottery kiln and to the remains of both amphorae and lamps. In 1992, emergency excavations directed by Cristina Garcia excavated a structure identified as a kiln and recovered abundant amphorae fragments of a locally produced Dressel 14 type. There is evidence of production of tiles, common ware and amphora. The study of the remains collected (terra sigillata and amphorae) in the excavations shows that Roman occupation of the site covers a period from the middle of the 1st century until the 5th century AD. The major production of the kiln area was the Dressel 14 fish sauce amphora centered in the middle/second half of the 1st century but the production of Almagro 51c is also attested. A preliminary macroscopic analysis of both the amphorae and the common ware show identical features. The aim of this paper is to present chemical characterization of the production of Manta Rota and to compare the results with different workshops in the Algarve region as Quinta do Lago, near Faro or S. Bartolomeu de Castro Marim, in the proximity of the studied area, in order to establish geochemical fingerprints of Manta Rota ceramic production center. Preliminary results point to a fine geochemical differentiation of the Manta Rota ceramics in comparison with the other two roman production centers of Algarve region

Radiocarbon and blue optically stimulated luminescence chronologies of the Oitavos consolidated dune (Western Portugal)

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

Chemical tracers of Lusitanian amphorae kilns from the Tagus estuary (Portugal)

In this paper, the characterization of Roman amphorae from the Porto dos Cacos (PC) and Quinta do Rouxinol (QR) workshops, in the Tagus estuary, dating to a period between the 1st and 5th century AD was carried out on the basis of instrumental neutron activation analysis data on 260 amphorae fragments, together with mineralogical compositional studies obtained by X-ray diffraction. Special attention was devoted to the study of the Dressel 14, Almagro 50/51c and Lusitana 3/9 amphorae in an attempt to establish whether or not it is possible to establish any correlation between the composition and typology, and between and within the production centres studied. A description of the geochemical patterns associated with each production centre was first carried out separately, followed by a discussion comparing the two centres situated in the same sedimentary basin, identifying diagnostic chemical tracers for each one; also, in certain cases, a relative correlation with the typology was achieved. Both the definition of reference groups and the attribution of amphorae to their workshop origin relied on the use of chemometric techniques for data structure analysis, coupled with geochemical data analysis, especially regarding trace element data and its geochemical behaviour and distribution according to the geological environment of the region. This approach complements and reinforces the conclusions drawn from typological and archaeological analyses. Considering the two kiln sites studied, we may talk of the production of two types of Roman amphorae in the lower Tagus, with the establishment of compositional groups defined according to their corresponding chemical signatures. The products of the PC workshop are characterized by high concentrations of Co, As and U, and low concentrations of Fe, Zn, Sb, Rb, K; QR workshop amphorae show instead higher concentrations of Fe, Sb, and also of Rb and Zn, and lower amounts of U. These results make it possible to understand the crucial importance of the lower course of the Tagus River within the framework of the analysis of the economy of the estuary at the time. This, in turn, may lead to a better understanding of production and trade within Lusitania and also with other Roman provinces

Neutron background estimates in GESA

Abstract. The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against ( ,n) neutrons to below 10 −8 cm −2 s −1 , it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP) estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10 −3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container

Distribution and chronological framework for Iberian variscite mining and consumption at Pico Centeno, Encinasola, Spain

AMS radiocarbon and OSL dating, and profiling were used to directly delimit periods of variscite production at Pico CentenoMine 2. These resultswere integratedwith analysis of otherwell-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 4thmillenniumBC, variscite use began to increase to its apogee in the first half of 3rd millenniumBC 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.info:eu-repo/semantics/publishedVersio

Cys-Ph-TAHA: a lanthanide binding tag for RDC and PCS enhanced protein NMR

Here we present Cys-Ph-TAHA, a new nonadentate lanthanide tag for the paramagnetic labelling of proteins. The tag can be easily synthesized and is stereochemically homogenous over a wide range of temperatures, yielding NMR spectra with a single set of peaks. Bound to ubiquitin, it induced large residual dipolar couplings and pseudocontact shifts that could be measured easily and agreed very well with the protein structure. We show that Cys-Ph-TAHA can be used to label large proteins that are biochemically challenging such as the Lac repressor in a 90 kDa ternary complex with DNA and inducer

Mineralogical attenuation for metallic remediation in a passive system for mine water treatment

Passive systems with constructed wetlands have been consistently used to treat mine water from abandoned mines. Long-term and cost-effective remediation is a crucial expectation for these water treatment facilities. To achieve that, a complex chain of physical, chemical, biological, and mineralogical mechanisms for pollutants removal must be designed to simulate natural attenuation processes. This paper aims to present geochemical and mineralogical data obtained in a recently constructed passive system (from an abandoned mine, Jales, Northern Portugal). It shows the role of different solid materials in the retention of metals and arsenic, observed during the start-up period of the treatment plant. The mineralogical study focused on two types of materials: (1) the ochre-precipitates, formed as waste products from the neutralization process, and (2) the fine-grained minerals contained in the soil of the wetlands. The ochre-precipitates demonstrated to be poorly ordered iron-rich material, which gave rise to hematite upon artificial heating. The heating experiments also provided mineralogical evidence for the presence of an associated amorphous arsenic-rich compound. Chemical analysis on the freshly ochre-precipitates revealed high concentrations of arsenic (51,867 ppm) and metals, such as zinc (1,213 ppm) and manganese (821 ppm), indicating strong enrichment factors relative to the water from which they precipitate. Mineralogical data obtained in the soil of the wetlands indicate that chlorite, illite, chlorite–vermiculite and mica–vermiculite mixedlayers, vermiculite, kaolinite and goethite are concentrated in the fine-grained fractions (<20 and <2 μm). The chemical analyses show that high levels of arsenic (up to 3%) and metals are also retained in these fractions, which may be enhanced by the low degree of order of the clay minerals as suggested by an XRD study. The obtained results suggest that, although the treatment plant has been receiving water only since 2006, future performance will be strongly dependent on these identified mineralogical pollutant hosts.Fundação para a Ciência e a Tecnologia (FCT

Modelling of Short-Term Interactions Between Concrete Support and the Excavated Damage Zone Around Galleries Drilled in Callovo–Oxfordian Claystone

peer reviewedProduction of energy from nuclear power plants generates high-level radioactive nuclear waste, harmful during dozens of thousand years. Deep geological disposal of nuclear waste represents the most reliable solutions for its safe isolation. Confinement of radioactive wastes relies on the multi-barrier concept in which isolation is provided by a series of engineered (canister, backfill) and natural (host rock) barriers. Few underground research laboratories have been built all over the world to test and validate storage solutions. The underground drilling process of disposal drifts may generate cracks, fractures/strain localisation in shear bands within the rock surrounding the gallery especially in argillaceous rocks. These degradations affect the hydro-mechanical properties of the material, such as permeability, e.g. creating a preferential flow path for radionuclide migration. Hydraulic conductivity increase within this zone must remain limited to preserve the natural barrier. In addition galleries are currently reinforced by different types of concrete supports such as shotcrete and/or prefab elements. Their purpose is twofold: avoiding partial collapse of the tunnel during drilling operations and limiting convergence of the surrounding rock. Properties of both concrete and rock mass are time dependent, due to shotcrete hydration and hydromechanical couplings within the host rock. By the use of a hydro-mechanical coupled Finite Element Code with a Second Gradient regularization, this paper aims at investigating and predicting support and rock interactions (convergence, stress field). The effect of shotcrete hydration evolution, spraying time and use of compressible wedges is studied in order to determine their relative influence