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The paper discusses the chemical-physical-petrographic features and decay processes of San Nicola Church (11th−14th century) building materials, one of the most representative Medieval Churches in ...

The ammonium salt of monoethyloxalate (AmEtOx) was investigated as a novel precursor for the conservation of carbonate stone substrates, such as biomicritic limestone and marble. Full characterization of treated and untreated authentic stone samples was carried out by means of SEM, X-ray powder diffraction, synchrotron tts-μXRD measurements, mercury intrusion porosimetry, determination of water transport properties, and pull-off tests. The improved solubility (1.49 M, 20.1% w/w) of AmEtOx as compared to that of ammonium oxalate (AmOx; 0.4 M, 5% w/w) results in the formation of microcrystalline phases 30–50 and 200–500 μm thick of calcium oxalate mono-(whewellite) or dihydrate (weddellite), on marble and biomicrite samples, respectively, after treatment with AmEtOx 5% and 12% w/w aqueous solutions. As a result, a reduction in the porosity of the stone samples and an enhancement of their cohesion are observed. DFT calculations, carried out to investigate the hydrolysis reaction leading from AmEtOx to AmOx, showed that the localization of the Lowest Unoccupied Molecular Orbital (LUMO) and the natural charge distribution account nicely for the tendency to hydrolyse observed experimentally, eventually leading to the formation of whewellite and weddellite on the stone surface., M. A., M. C. A., F. I., and V. L. thank the Fondazione di Sardegna (FdS) and Regione Autonoma della Sardegna (RAS) (Progetti Biennali di Ateneo FdS/RAS annualità 2016) for financial support. A. P. acknowledges RAS for the funding in the context of the POR FSE 2014–2020 (CUP F24J17000190009). Comune di Cagliari, Segretariato Regionale per i Beni e le attività culturali per la Sardegna, and Soprintendenza Archeologia, Belle Arti e Paesaggio per la città metropolitana di Cagliari e le province di Oristano e Sud Sardegna are kindly acknowledged for supporting the Cultural Heritage Conservation Laboratory “Colle di Bonaria” in their research and teaching activities.

In restoration and conservation practices, biocide treatments are considered one of the most practical approaches to remove biological colonization on artworks, including stone. Numerous studies have focused on the short- and long-term effects of these treatments and recently many alternative methods to reduce their potential hazards to human health and the environment have been proposed. In this study, a solvent gel containing dimethyl sulfoxide (DMSO), already used to clean paintings, was applied on colonized marble artifacts at the monumental cemetery of Bonaria (Cagliari – Italy) to remove biological patinas. The protocol efficiency was evaluated by scanning electronic microscopy, rugosimetric and colorimetric measurements and growth tests. A comparative study also was performed to validate the method using biocides currently used in conservation. The results demonstrate that DMSO solvent gel is efficient at removing patinas on stone, of low impact, easy to use, inexpensive and can be considered a more practical alternative to biocide treatments.

Sulphur and nitrogen oxide pollutants cause acid rain that can eventually lead to the dissolution of calcite in marble and limestones. Calcium oxalate is an inorganic protective agent, which is obtained by treatment with ammonium oxalate. The functionalization of oxalic acid to give monoesters and monoamides (oxamates) allows tailoring the solubility of the relevant ammonium and calcium salts. In this context, theoretical calculations carried out at the Density Functional Theory (DFT) level were exploited to investigate the capability of oxalate, methyloxalate, phenyloxalate, oxamate, methyloxamate, and phenyloxamate to interact with the calcium carbonate lattice. An in-depth validation based on the structural data showed that DFT calculations with the PBE0 functional along with a single or triple-zeta def2 basis set allow understanding the different reactivity of the oxalate and oxamate derivatives and their efficiency in interacting with stones containing calcium carbonate, such as Carrara marble and biomicritic limestones.

The aim of the research is to investigate the role of the microclimatic conditions and their variations on the decay due to salt crystallisation, observed in a semi-confined archaeological site, in an urban area. A microclimatic monitoring was carried out in the site to detect temperature and relative humidity and their respective variations. Statistical methodology was conducted to examine the microclimatic data with seasonal, monthly and daily analyses. Different zones of the site were monitored and a microclimatic zoning was detected. The outside environment influences the most external zones of the site, while in the confined ones a high relative humidity was detected in all the seasons. The comparison between the hygrothermal conditions monitored in the site and those thermodynamic favourable to salt crystallization revealed a very harmful risk of salt damage for the archaeological structures.

In this work we have tested the fluidized bed desulfurization performance of lime particles obtained by means of a limestone slow calcination pre-treatment technique. This performance was compared to that of the parent untreated limestone particles. The occurrence of particle fragmentation and attrition during the fluidized bed operation was also investigated with a specific test protocol for both raw limestone and pre-treated lime sorbent. Two particle size ranges were tested under typical fluidized bed coal combustion conditions ( T = 850 °C; SO 2 = 1800 ppm). The experiments were complemented by porosimetric and morphological (SEM) analyses of the sorbent. Results showed that limestone pre-treatment was able to preserve the high mechanical strength of the parent particles as opposed to the fast in situ calcination typically active in fluidized beds. In addition, a high calcium reactivity and final conversion were observed for the pre-treated lime particles, leading to a SO 2 capture capacity per unit mass of sorbent much higher than that obtained with the untreated limestone. Simple economic evaluations suggest that the use of the pre-treated lime in place of limestone can involve significant economies for fluidized bed coal combustor operators.

In order to assess decay in the mechanical characteristics of re-exposed Reinforced Concrete (RC), it is crucial to recon- struct the temperature time history and the evolution of strain and stress elds. In this paper, the state of the art of assessment methods is presented and applied to a real structure damaged by re. It is a prestressed RC industrial warehouse located in the outskirts of the city of Cagliari (Italy). The collected data of several assessment methods are presented in order to produce the owchart of an integrated approach for post- re investi- gation. Among the various techniques, the authors highlight a thorough laser scanner geometric survey and destructive and non-destructive testing. In addition, the temperature distribu- tion and its time history has been reconstructed by means of optical and Scanning Electron Microscopy, X-ray diffractom- etry, Thermogravimetric Differential Thermo-Analysis and calibrated Colorimetry. Actually, refurbishment is needed, but the structure withstood the re very well. Central columns displayed the most impor- tant damage, and several beams presented important de ec- tions having lost the prestressing actions of the tendons.

The present work focuses on the specific surface area increase, and on the related chemical reactivity enhancement of quartz powders submitted to mechanical processing. The mechanical treatment was carried out in a suitably developed ball mill allowing the control of the frequency and energy of the impacts between ball and reactor. The specific surface area was directly measured by nitrogen physisorption, whereas electron microscopy was used to determine the size distribution of powder particles. Based on the experimental results, a simplified mathematical model was developed to describe the process of specific surface area increase on a phenomenological basis. The model permits to gain valuable information on the amount of powder processed in individual impacts. The density of reactive centers at the surface of powder particles was also estimated by using the neutralization of a free radical as a test reaction. It is shown that the surface density of reactive centers increases with the energy of collisions.

The ammonium salt of N-phenyloxamic acid (AmPhOxam) was synthesised, characterised by FT-IR, FT-Raman, UV-Vis, 1H-NMR spectroscopic methods and single crystal X-ray diffraction, and evaluated as a protective and consolidating agent for calcareous stone substrates under mild conditions. Hydro-alcoholic solutions of AmPhOxam were tested for the treatment of naturally weathered white marble and biomicritic limestone. Mercury intrusion porosimetry, FT-NIR spectroscopy measurements and SEM microscopy showed the formation of a superficial protective layer of crystals of the corresponding monohydrated calcium salt, CaPhOxam, on both treated stones. Publisher PDF

The ammonium salts of oxamate (AmOxam) and monomethyloxalate (AmMeox), structurally related to ammonium oxalate (AmOx), were synthesized and characterized as protecting agents/filler for calcareous stone substrates. Both compounds featured an improved solubility in water and alcoholic-water mixtures with respect to AmOx. While AmOxam is stable in aqueous solution and reacts with calcite to afford the corresponding insoluble calcium oxamate (CaOxam), AmMeox spontaneously undergoes hydrolysis to give ammonium monohydrogen oxalate hemihydrate (AmBiox) and calcium oxalate (CaOx). Both compounds have been tested for the restoration of naturally weathered marble and biomicritic limestone. The formation of a superficial layer of CaOxam and CaOx was observed on stone samples treated with AmOxam and AmMeox, respectively, depending on the solvent mixture. A quantum–mechanical study was carried out at DFT level in order to investigate the nature of the interactions occurring between the lithic substrate (calcite) and the passivating agents, showing how the structural modifications on oxalic acid derivatives can be exploited to fine-tune their interaction with the calcite surface.

The migmatites of Porto Ottiolu, NE Sardinia, underwent polydeformation and partial melting during the Hercynian orogeny. The migmatites are cross-cut at the outcrop scale by leucogranite dykes and tourmaline-bearing pegmatite dykes. Three groups of small-scale structures (D1, D2, D3) and two types of leucosomes formed. One leucosome type is concordant with the main foliation, while the other is discordant and mostly intruded along shear zones. Type I leucosomes consist of quartz, plagioclase, K-feldspar, biotite, and muscovite. Type II leucosomes contain additional garnet. The mesosomes show a variable texture defined by the orientation of biotite parallel to the most pervasive foliation D2. Based on mineralogy and textural features, two main types of mesosomes have been distinguished: MI mesosomes are texturally similar to the Ordovician orthogneiss outcropping in NE Sardinia, while MII mesosomes are characterised by a vague foliation due to a lower biotite content. Leucosomes are enriched in Rb, Sr, Ba, and Pb, and depleted in Li, Sc, V, Cr, Co, Y, Zr, Nb, Cs, Th, and U compared to the mesosome. The total REE content varies from 40 to 100 ppm in the leucosomes and from 120 to 180 ppm in the mesosomes. Most leucosomes of both types show a positive Eu anomaly and moderately fractionated REE patterns. The garnet-bearing type II leucosomes are characterised by high HREE content. Three metamorphic stages: M1, M2 and M3 have been recognised in the migmatite of Porto Ottiolu area. M1 assemblages have been only inferred on the pelite migmatite. Anatexis via the muscovite dehydration melting reaction occurred at T = 700–720 °C and P ∼ 6–8 kbar during the M2 stage. M3 is an incipient recrystallisation defined by the formation of muscovite. The leucogranites are peraluminous with more than 1.1% normative corundum. It is unlikely that the leucogranite, even though enclosed in the migmatite of Porto Ottiolu, should have been formed by the partial melting of the same protolith. Anatexis im hercynischen Basement Nordost-Sardiniens, Italien: eine Fallstudie vom Porto Ottiolu-Migmatit Wahrend der hercynischen Orogenese wurden die Migmatite von Porto Ottiolu in Nordost-Sardinien aufgeschmolzen und mehrfach deformiert. Die Migmatite werden im Aufschlus von Leukogranit- und Turmalin-fuhrenden Pegmatitgangen durchschlagen. Drei Gruppen von Kleinstrukturen und zwei Typen von Leukosomen sind unterscheidbar. Ein Leukosomtyp ist konkordant zur Hauptschieferung, wahrend der zweite Typ diskordant ist und entlang von Scherzonen intrudierte. Typ I Leukosome bestechen aus Quarz, Plagioklas, Biotit und Muscovit. Typ II Leukosome enthalten zusatzlich Granat. Die Mesosome zeigen variable Textur, die vor allem durch die Regelung von Biotit parallel zur penetrativen Foliation (D2) gekennzeichnet ist. Mineralogisch und texturell lassen sich zwei Typen von Mesosomen unterscheiden: M I Mesosome sind texturell ahnlich den ordovizischen Orthogneisen in Nordost-Sardinien, M II Mesosome sind durch eine undeutlichere Foliation, bedingt durch den geringeren Biotitgehalt, gekennzeichnet. Im Vergleich zum Mesosom sind die Leukosome an Rb, Sr, Ba und Pb angereichert, an Li, Sc, V, Cr, Co, Y, Zr, Nb, Cs, Th und U abgereichert. Die gesamten REE Gehalte schwanken zwischen 40 und 100 ppm in den Leukosomen, und zwischen 120 und 180 ppm in den Mesosomen. Die meisten Leukosomproben beider Typen zeigen eine positive Eu Anomalie und masig fraktionierte REE Muster. Der Granat-fuhrende Typ II ist durch hohere HREE Gehalte gekennzeichnet. Drei Stadien der Metamorphose, M1, M2 und M3 lassen sich in den Migmatiten von Porto Ottiolu unterscheiden. M1 Paragenesen sind auf pelitische Migmatite beschrankt. Die Anatexis infolge von Muscovit-Dehydrationsreaktionen erfolgte bei 700–720 °C und ca. 6–8 kbar wahrend des M2 Stadiums. M3 ist eine beginnende Rekristallisation mit der neuerlichen Bildung von Muscovit. Die Leukogranite sind peraluminos mit mehr als 1.1% normativem Korund. Obwohlsie in den Migmatiten auftreten, ist es unwahrscheinlich, dass sie sich durch Aufschmelzung aus denselben Ausgangsgesteinen gebildet haben.

On the basis of a previous detailed characterization of the Sardinian bentonites for pelotherapy applications wCara, S., Carcangiu, G., Padalino, G., Palomba, M., Tamanini, M., 2000. The bentonites in pelotherapy: chemical, mineralogical and technological properties of materials from Sardinia deposits Italy.. Appl. Clay Sci. 16, 117-124 this issue.x, three commercial bentonites have been selected for detailed studies. The thermal properties of the pastes, prepared with these bentonites at different moisture, have been compared with the properties of a peloid, commonly used in the spa of Benetutti northern Sardinia.. The cooling kinetics of the bentonites along with the thermal mud have been studied using an experimental apparatus that reproduces the conditions during the application of a cataplasm. A mathematical model for the cooling kinetics has been obtained by means of a theoretical cooling equation, with instrumental constants derived from a reference paste TiO2 at 50% moisture.. The heat capacity of the pastes introduced into the model was calculated from chemical and mineralogical data. The methodology developed can be used in other laboratories of the thermal centres to determine the quality and ability of the bentonitic materials for pelotherapy. q2000 Elsevier Science B.V. All rights reserved.

Mn-rich beds occur within the “Brecce di Seravezza” Formation (BSFm) intercalated between Norian metadolostone-Megalodontic marble and Hettangian marble in the Alpi Apuane, (Italy). The BSFm is a rockfall talus deposit that accumulates at the base of the footwall scarp of normal faults bordering extensional marine coastal basins. The type sequence of metabreccia ends with a bed of chloritoid schist interpreted as the metamorphic equivalent of lateritic soils. The four main types of Mn mineral assemblages are: (1) braunite, piemontite, and rare hausmannite; (2) piemontite, braunite, hollandite and minor rhodochrosite and kutnahorite; (3) braunite, hollandite and rare piemontite. The other minerals are: quartz, calcite, muscovite, phlogopite, baryte and minor hematite, rutile and apatite. During the Alpine orogeny pressures of 4–6 kb and temperatures of 350 °–380 °C were attained; Mn assemblages with hematite and phlogopite indicate ƒO2 > 10−8 for T= 350 °C and ƒO2 ≥ 10−6 when braunite appears. On the Mn-rich rocks Ti, Fe, Nb, Sn, Ta, Hf, Th, Ga, Rb, Pr, K, Na, Nd were identified as detrital in origin and are positively correlated with Al. U is positively correlated with Co, Pb, Bi, Mo. The rare earth element patterns normalized to seawater show a negative slope towards the heavy rare earth elements, with positive Ce anomalies in some samples, positive Ce and Eu anomalies in other samples and negative Ce and positive Eu anomalies in a third group. The Eu concentrations are nearly constant and the Eu anomalies reflect differences in the concentration of other rare earth elements; for Ce, a positive correlation with Al2O3 + SiO2 indicate that a detrital signature prevails on that produced by duration of seawater exposure. But a significant good correlation of La, Tm, Lu with Mg could indicate, at least for these elements a seawater signature. Only in some samples, Ba, Eu, Sr show anomalously high concentrations, likely of hydrothermal origin. However, generally in all the chemical variation diagrams the BSFm samples fall outside the field of hydrothermal and hydrogenous deposits as defined in the literature for other Mn deposits. In addition, metabasites and metavolcaniclastic beds are absent from the BSFm sequence and BSFm coastal basins were for the most part separated from the open ocean and related streams, that must be excluded as possible Mn-sources. Owing to the arid climate of Late Triassic the runoff was negligible and the groundwater, oxidizing and alkaline, were unable to mobilize Mn. The BSFm basins are then the most suitable depositional environment for Mn. The water column was stagnant and stratified. Only where bottom of the basin was deeper than the oxic-anoxic boundary, reducing marine bottom waters percolated within the fractured basement and leached Mn from disseminated minerals of metamorphic rocks and, then, rising along fault and fractures, supplied Mn to the bottom waters. Afterwards, when tectonic uplift and sealevel drop brought the bottom into the oxic field, Mn precipitated and formed the Mn-rich matrix of the BSFm deposits.

In order to extend the application of photovoltaic power generation, new integrated solutions with the environment have to be studied and adopted. In the next future, one important solution could be the application of photovoltaic power generator into terrestrial desert surfaces. The present paper analyses the possible production of electrical energy by photovoltaic systems in areas characterized by an high level of insolation in order to maximize the global energy conversion. In this context, it has been developed a new and very innovative photovoltaic technology for the realization of solar panel suitable for the extreme condition and at the same time it is studied and analyzed the electrical components and the correct strategy to connect the solar plant to the end users. The study concerns a preliminary technical analysis on the solar network configuration and presents different PV network configurations, discussing benefits and drawbacks for each one of them.

Unfired earth is a traditional building material in many countries, and is still used in different parts of the world. It may also constitutes a resource in the construction sector, due to its limited environmental impact and compatibility with the pronciples of eco-sustainability. The paper focuses on the evaluation of the environmental parameters affecting buildings in unfired earth situated in different regions of Sardinia, Italy, with the aim of identifying the main damage processes in progress, with particular regard to the impact of multipollutants. Results show that unfired earth buildings, in both urabnised and rural areas, are particularly vulnerable towards water-derived parameters, while pollutants mainly affect the plastering layers of structures in cities. In a perspective of preventive conservation, the monitoring of environmental parameters critical to the durability of the earth heritage appears essential.

In the past years, the Centro Studi Geominerari e Mineralurgici of the C.N.R. of Cagliari has carried out an investigation on sand deposits located along the coasts and the continental shelf of Sardinia. These studies determined titanomagnetite, zircon, cassiterite, monazite and V, Hf, REE, Th, etc., particularly in the Santa Margherita area (southwestern Sardinia). The economic interest of some of these mineral species and elements suggested the need for further investigation. Beneficiation tests, plasma chemical analyses and electron-microprobe analyses were therefore carried out. The most significant aspects of the research and the results obtained are reported for each sampled zone.

Raw and calcined kaolinic clays from a mid-western Sardinia (Italy) sector were investigated in order to evaluate the feasibility of lime-activated materials. The great reserves of clays in this mining district, which are not well suited to traditional ceramics because of their low kaolinite content, excess of quartz, iron oxides, alunite, and the open pit exploitation, suggest an alternative use for these materials. The kaolinic clay samples and a reference kaolin were thermally activated in a laboratory oven at 530, 630 and 800 °C temperatures. Pastes of thermally activated and non-activated materials with lime, in the ratio of 1 : 1 by weight and water / solid ratio 1 : 2, were prepared and cured at different times. The reactions that took place in the metakaolin–lime–water systems were monitored using thermogravimetric analysis, differential thermal analysis and X-ray diffraction analysis. The results of pozzolanic tests and laboratory analyses were combined and offered very interesting property relations compared with a high-grade kaolin used as reference sample, even though a slower hydration kinetics. The large availability of the Donnigazza kaolinic clay reserves encourages the use of these materials in the binders sector and particularly in the Cultural Heritage sector as pozzolanic additives for restoration mortars.

Spa centres in northern Italy use clayey admixtures for the formulation of muds to be used in pelotherapy. The basic ingredient (“virgin” clay) is a dressed bentonitic geomaterial with mineralogical composition: smectite 60–70%, illite 5–10%, kaolinite 10–15%, quartz 5–10%, calcite 5–10% and feldspars 2–3%. The peloid muds are obtained by “maturation” of the virgin clay with mineral waters gushing out in situ which have different geochemistry: sulphureous, Ca-sulphate, Ca–Mg-sulphate and Br–I-salty (after the Italian regulation DPR 105/92). The maturation treatment is varying with respect to the mixing procedure and lasting time. Peculiar parameters have been tested to verify the effects of various maturation treatments, i.e., changes with respect to virgin clay. Formation of organic matter is due to the presence of microorganisms and algae in the maturation habitat. The Noteworthy was the influence of high-pH value of the virgin clay on the pH of peloid muds (in fact, the pH of the used mineral waters is ranging around the natural value). Furthermore, the temperature reached by the peloid muds after 20 min of application (calculated after an innovative mathematical model) is influenced by water retention. An increase in plasticity index and a slower cooling are considered to improve the quality of the obtained peloid muds for pelotherapy. The observed different cation exchange behaviour and soluble salt content could be discriminant for either dermatological masks or thermal body cataplasms. A need of regulation (standard procedures) is suggested to certificate the clay geomaterials suitable for pelotherapy and also for drugs formulation.

Bentonite muds are suited for use in pelotherapy due to their typical properties of high swelling (>25 ml/2 g), specific heat (Cp) and ease of handling, generally obtained at a material viscosity of 400 cps. This paper reports chemical, mineralogical and technological properties of Sardinia bentonites, to identify the most suitable materials for pelotherapy pastes. Their characteristics have been compared to the peloid properties commonly used in the spa of Benetutti (Northern Sardinia). On the basis of the mineralogical, chemical and technological characterization of the samples, besides their proximity to the most important regional spas and/or thermal sources, Costa Paradiso, Pedroseddu, Laconi, Busachi, Siurgus-Donigala and Giba bentonites are the most suitable Sardinia materials for pelotherapy. The results of this study also show that a complete characterization of clay materials is necessary in pelotherapy paste preparation. The utilization and/or addition of bentonites, largely available in Sardinia at relatively low cost, can improve the thermal mud quality for curative purposes.

Eclogitic rocks are hosted within gneisses and migmatites of the Hercynian basement of NE Sardinia. They are characterized by two compositional layers: garnet-pyroxene rich-layers and amphibole-plagioclase layers. The former contain structural, mineralogical and compositional relics of eclogite facies re-equilibration. Four stages of evolution have been identified: an eclogite stage, a granulite stage and a retrograde amphibolite to greenschist stage. A possible pre(?)-eclogite stage is documented by inclusions of euhedral tschermakitic amphibole + zoisite within the core of garnet. This early stage was followed by an increase in pressure under which the eclogite climax developed (T up to 700 °C, P =13-15 kbar), as documented by omphacite inclusions towards the rim of garnet. Characteristic mineral reactions after the eclogitic stage are: omphacite → diopside + plagioclase (symplectite) and garnet → orthopyroxene + plagioclase. These reactions testify the presence of a granulite stage during which the peak of metamorphism was reached (T up to 870'C, P ≈ 10 kbar). The orthopyroxene → cummingtonite + quartz and garnet + diopside → hornblende + plagioclase (kelyphite) transformations indicate extensive amphibolite retrogression (T = 550650 °C, P = 3-7 kbar). Finally, actinolite and chlorite developed (greenschist stage) at falling temperature and pressure (T = 300-400 °C, P < 2-3 kbar).

Recent studies on albitite rocks located in the granodiorite complex of Central Sardinia have revealed that epidote has a widespread occurrence as a light rare-earth element (LREE)-bearing accessory common phase. Titanite has been recorded as a heavy rare earth element (HREE)-bearing mineral. The Hercynian granodiorite complex of Central Sardinia is composed chiefly of quartz, Ca-plagioclase, K-feldspar and biotite and of a wide variety of secondary assemblages, mainly allanite, titanite and zircon. Albitic plagioclase and quartz are the main mineral components of the albitites. Additional minerals include, besides allanite and epidote, a more calcic-plagioclase (oligoclase), K-feldspar, chlorite, titanite and more rarely muscovite. The mineral assemblages and REE-bearing minerals of albitites were analysed by wavelength dispersive spectrometry (WDS). Chemical data suggest that there is a near complete solid-solution between epidote and allanite whereas little variations in HREE of titanites were detected. In epidote-group minerals a pronounced zoning in REE was observed while titanite was recorded unzoned. Textural relations were studied by SEM to distinguish primary from secondary epidotes. Chemical criteria to recognize magmatic from alteration epidotes were also applied. The alteration epidotes mainly occur and generally originate from plagioclase alteration and from leaching of magmatic allanite. Comparison of textures using both the SEM technique and EPMA data showed that the characteristic ‘patchy zoning’, observed in epidotes, corresponds with different amounts of REE in these minerals.The schematic model proposed for the epidote-forming reactions during the metasomatic processes that affected the granodiorites involves: (i) the instability of the anorthitic component of plagioclase; (ii) the simultaneous formation of albite; (iii) the leaching of the magmatic allanite with a redistribution of REE in the epidotes of the albitites.