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REE have unique properties that are mostly used to manufacture high tech devices. Most REE have geochemical properties that cause them to be typically dispersed and not often found in concentrated and economically exploitable forms, and difficult to separate. The ENVIREE project aims to develop environmentally friendly and efficient methods for their extraction from secondary sources. REE contents of tailings from four legacy mining sites have been obtained by INAA and analysed by 57Fe Mössbauer spectroscopy. REE concentrations in the tailings of Covas and Cumieira are more dependent on the REE contents of the primary ores and the treatment to extract the target metals than on the nano-sized oxides present. The tailings’ size, REE contents and Mössbauer results support the selection of the Covas tailing as the one to be submitted for further steps of REE extraction on the framework of the project.

A lacustrine carbonate facies has been investigated in Middle Miocene successions of the western side of the Moura-Marmelar basin, Southern Portugal in order to evaluate paleoenvironments in which carbonates formed, by using geochemistry and mineralogy. The studied formation corresponds to a recent unearthed section of a calcrete with an homogeneous carbonate facies comprising fine, whitish, and powdery material, and the only detected difference is a slightly hardness decrease towards the top, as well as an increase of weathered rock fragments (schist). The calcrete is calcium rich, even some magnesium enrichment was observed at the middle level, which is differentiated by a general depletion of all chemical elements, particularly REE, in both the bulk and clay-size fraction. Regarding the mineralogy, calcite prevails, and dolomite is only present in the middle level of the calcrete, together with a smectite enrichment, suggesting changes to more alkaline and low drainage, lacustrine and arid to semi-arid conditions.

Roman military camps are temporary defensive enclosures, usually rectangular-like with rounded corners and defended by an external ditch and earthen embankment or stonewall. The use of remote sensing techniques has contributed to the identification of several new Roman military sites in northern Portugal and Galicia [1]. In the present work, two of those enclosures located in Northwest Iberia are considered: Lomba do Mouro (Castro Laboreiro, Melgaço and Verea, Ourense) and Alto da Raia (Tourém, Montalegre and Calvos de Randín, Ourense). Despite the increase in archaeological data concerning this type of enclosures, aspects related to the definition of the dynamics of construction, occupation and post-abandonment remain to be clarified. The Roman camps, being of temporary use, have a very limited associated material culture. Added to this constraint are signs of abrasion (acidic soils) and post-depositional taphonomic processes that make it difficult to establish the dynamics and chronology of the enclosures, constituting a challenging case study. In this sense, a multidisciplinary approach has been applied combining archaeological data, luminescence dating, and chemical and mineralogical compositional studies of the accumulated materials. The results of luminescence dating of the materials sealed by the stonewalls at Lomba do Mouro point to a Roman Late-Republican chronology. Concerning the materials accumulated in ditches and earthen embankment at Alto da Raia, the mineralogical composition points to the anthropogenic intention/selection of materials. Both studies, dosimetry by luminescence and compositional ones, are in accordance with an inversion of the stratigraphy related to the earthen embankment construction and with the hypothesis of reusing the nearby pre-existing prehistorical materials to infill the ditch. [ABSTRACT FROM AUTHOR]