La région du Haut Vénéon, objet de cette étude, est située dans la partie septentrionale du massif du Pelvoux, qui est l'un des massifs cristallins externes des Alpes occidentales. Les principaux événements métamorphiques et magmatiques sont les suivants, par ordre chronologique croissant : - Métamorphisme blastomylonitique antéhercynien se traduisant notamment par la cataclase de* minéraux relictuels (plagioclase antiperthitique, hornblende brune, grenat "pyrope", sillimanite prismatique, disthène) et la blastèse de quartz sous forme de séries de plaquettes soulignant la schistosité blastomylonitique. Les conditions approchées de ce métamorphisme sont estimées par A. PECHER, 1970 P s = 6, 5 à 8, 5 kb ; PH20 = 2 à 4 kb ; T = 600 à 650° C. - Epanchements régionaux de laves basiques (futures amphibolites). - Métamorphisme "principal", régional, à biotite-grenat-sillimanite fibreuse-cordiérite, auquel est associée une mobilisation régionale. Les conditions de ce métamorphisme " hercynien " de faciès amphibolite supérieur sont ainsi déterminées: T = 660° C ± 30°C; PH20 = 3,7 à 6,1 kb avec Ps >=PH20 -Filons rhyolitiques et granites intrusifs hercyniens (datés dans tout le massif par géochronologie), suivis de leurs cortèges aplo-pegmatitiques et de lamprophyres. - Dépôts houillers, triasiques et liasiques. - Métamorphisme post-liasique lié à la schistosité affectant le socle où ils donnent en particulier les "gneiss ocellaires" et les "granites écrasés", et la couverture sédimentaire principalement liasique. Les recristallisations de quartz, de plagioclase en cristaux hexagonaux granulés, de biotite à pléochroïsme de brun délavé à brun sombre, de chlorite, de séricite, d'épidote témoignent d'un métamorphisme de faciès schistes verts supérieur. - Métamorphisme post-oligocène à prehnite - pumpellyite - Filons de quartz -épidote - Métamorphisme à laumonite-analcime Du point de vue tectonique des déformations continues et discontinues se surimposent à ces événements métamorphiques et magmatiques .Leur axe de raccourcissement maximal est tantôt d'orientation est - ouest, tantôt d'orientation nord- sud. Nous noterons notamment les plis ouverts anté-mobilisat d'amplitude régionale, d'axe nord - sud. Ils sont tordus à l"alpin" par une grande virgation d'amplitude régionale (N 20 à N 150). Celle-ci se décompose dans certains secteurs en des suites de petites virgations, d'amplitude kilométrique,à concavité tournée alternativement vers l'Ouest ou vers l'Est. Elles sont liées à de grands décrochements : dextres orientés N 40 et senestres orientés N 130. Toutes ces virgations affectent notamment la schistosité "alpine" qui a affecté le sédimentaire (surtout le Lias) pincé dans le socle et le cristallin (principalement "gneiss ocellaires" et "granites écrasés"). Deux grands domaines structuraux sont individualisés. Ils sont schématiquement séparés par l'importante faille de décrochement en relais "N 40" Arias - Mariande - Plat de la Selle (cL carte structurale en conclusion). Le sec teur septentrional est tectoniquement très perturbé. C'est une grande zone de faiblesse du socle. Elle a "joué" à plusieurs reprises : schistosité anté-mobilisat des blastomylonites et schistosité "alpine" des " gneiss ocellaires " et des 'granites écrasés'. Ces schistosités sont affectées par le système de décrochements "N 40" et "N 130", et par la famille de failles senestres d'orientation nord-sud. Le secteur méridional est "calme". Les plis anté mobilisat et la concentration du mobilisat à la base des amphibolites sont notamment aisément identifiables.

The work presented in this thesis utilizes several geological methods to investigate the origin and evolution of the supracrustal rocks in the Palaeoproterozoic Hamrånge Group (HG) in the south-central Swedish Svecofennian. The first paper is based on whole-rock geochemistry to show the plate tectonic setting of volcanic rocks within the HG. This indicates that the environment was probably an oceanic volcanic arc. Geochronology, used in paper two, shows that the volcanism was active at 1888±6 Ma and that the sediments forming the stratigraphically overlying quartzite were deposited after 1855±10 Ma, with provenance ages overlapping both the volcanic rocks and the 1.86-1.84 Ga continental margin Ljusdal granitoids. In the third paper, thermobarometry was applied to samples from the HG, the migmatitic Ockelbo sub-domain to the south, and the 1.81 Ga Hagsta Gneiss Zone (HGZ) that separate these two units. The results show distinct differences in the metamorphic conditions that have affected the HG and the Ockelbo sub-domain, supporting previous interpretations that the HGZ is an important crustal structure, possibly a terrane or domain boundary. Paper four deals with the structural geology of the Hamrånge area. The study shows that the volcanic rocks and the underlying mica schist have been subjected to three deformation episodes (D1-D3), while the uppermost quartzite was most likely only affected by D2 and D3. While structures related to D1 are rarely seen, D2 resulted in a penetrative foliation, strong lineations and NW-vergent folding and thrusting. D3 is a result of a N-S compression that formed regional E-W folds and steep, ca. NW-SE shear zones, e.g. the HGZ. The results presented in this thesis, integrated with previously published data, outline a model for the geological evolution of the Hamrånge area: At 1.89 Ga a volcanic arc formed that subsequently collided with a continental margin resulting in the first deformation episode, D1, and probably a metamorphic event. This was possibly followed by an extensional period, after 1855±10 Ma, forming a basin that accumulated sediments later to form the quartzite stratigraphically on top of the volcanic rocks. The second deformation episode, D2, formed a fold-thrust belt when the supracrustal HG was thrusted to the NW, on top of the 1.86-1-84 Ga Ljusdal Domain. Flattening and a second metamorphic period followed this thickening of the crust. The last ductile deformation, D3, caused by regional tectonic forces, resulted in F3-folds that matured into ca. 1.8 Ga large-scale, steep shear zones transecting the Fennoscandian Shield.

Gneiss domes are structural features associated with orogens worldwide. This study provides a structural analysis of the domes of the Harvey Cardiff Domain, associated with the Grenville Orogeny. Structural data and oriented samples were collected during field work in the summer of 2012. These were used in combination with published and unpublished foliation and lineation data to analyze structural patterns and determine a mechanism of formation for the domes. The end member scenarios for dome formation were taken from the gneiss dome classification scheme devised by Yin (2004). Most of these mechanisms were eliminated based on a lack of necessary large scale geologic features in the region of the study area. An analysis of the foliation pattern of the Cheddar and Cardiff domes was most consistent with formation by diapirism. However, the foliation patterns of the domes differ from the expected diapiric pattern, and seems to represent a non-horizontal slice through a diapir, cutting through a diapir neck in the north and a diapir hat in the south. This pattern can also be explained by rotation of diapiric foliation due to strain induced by the main orogenic event. This hypothesis was tested using COMSOL, a finite elastic strain model, and found to be realistic. With the methods used in this study it is not possible to tell whether this rotation occurred after or during dome emplacement.

The Kiosk domain in the Central Gneiss Belt, southwestern Grenville Province, Ontario comprises ca.1655 Ma orthogneisses and volumetrically minor ca. 1480-1460 Ma parag- neisses that were affected by granulite-facies metamorphism between ca. 1480 and ca. 1000 Ma. The objectives of this study are: (i) to determine the protolith ages from the Kiosk domain and the underlying southern Bonfield Batholith; (ii) to determine the tim- ing of major tectonic episodes; (iii) to determine the pressure-temperature conditions of peak metamorphism; and (iv) to use these data to constrain the position of the Allochthon Boundary Thrust in the southwestern Grenville Province.

The Ngoye Granite Gneiss Formation is located in the Natal sector of the Proterozoic Namaqua-Natal Mobile Belt, about 10 km southwest of Empangeni. It forms a prominent east-west trending elongate whalebacked massif some 30 km in length, within amphibolitic gneisses and schists of the Tugela Group. A suite of twelve different, gneissic granitoids has been-recognised within the Ngoye Formation on the basis of field relationships, mineralogy and supportive geochemistry. They range in composition from peraluminous syenite to peralkaline granite. Peraluminous varieties are typically muscovite and garnet-bearing whereas metaluminous granites in the formation contain olivegreen biotite and/or hornblende and sphene. Riebeckite, aegerine and yellow-brown biotite, with accessory fluorite and zircon are characteristic of the peralkaline granites. Geochemically, the samples analysed display a range in SiO₂ from 63,79 - 78,47∞, are extremely depleted in CaO and MgO, while being enriched in Na₂O and K₂O. Depletion of CaO relative to alkalis is shown by an alkali-lime index of only 36, suggestive of an alkalic character. The agpaitic index (A. I. = mole Na₂O + K₂O/AL₂O₃) of the peralkaline samples ranges between 1,02 and 1,16; which classifies them as granites of comenditic affinity. Various chemical classification schemes have been tested and evaluated, of which the RI - R2 multicationic diagram provides results most similar to modally-derived terminology. Accordingly, the Ngoye granitoids are shown to range from minor syenites and alkali granites to predominant monzo - and syeno-granites. Trace element data indicate that the peralkaline granites are enriched in Nb, Zr and Zn relative to the other, non-peralkaline, granites in the formation. In addition, radioactive, magnetite-bearing quartz-rich rocks associated with the peralkaline granites, have extremely enhanced contents of Nb, Zr, Y, Zn, U, Th and to a lesser extent Sn and W. Peraluminous and near-peraluminous granites have the highst Rb/Sr and Rb/Ba ratios of all samples analysed, as well as enhanced Sn, U and Th contents while Zr is notably depleted. Small, muscovite-rich pods associated with muscovite-bearing granites are highly enriched in Sn. The application of certain discriminants based on modal and geochemical parameters has shown the Ngoye Formation to comprise typical "A" - type granites. "A" - type granites are characteristically intruded as ring complexes into anorogenic or post-orogenic tectonic settings in attenuated or epiorogenically-domed continental crust. Comparison of the Ngoye Formation wi th the well-known "younger granite" complexes of Nigeria and Saudi Arabia reveals marked similarities. The inference is therefore that the Ngoye Formation represents a metamorphosed "postorogenic" granite complex with most of the hallmarks of "A" type or "within-plate" magmatism. Four phases of deformation (D₁ to D₄) are recognised within the area mapped. Evidence of D₁ deformation is rare, but rootless folds within the transposed layering in the amphibolitic country rocks reflect the intensity of this prograde metamorphic event, M₁, during which upper amphibolite grades were achieved. Field evidence shows that the Ngoye granites were intruded after the D₁ event and prior to D₂. This latter event caused widespread folding about east-west F₂ axes, with the development of a pervasive S₂ planar fabric within the antiformally folded Ngoye Formation. S₂ is locally developed in the amphibolitic country rocks. The D₂ event culminated in the development of northward-directed overthrusting and retrogressive ,M₂, metamorphism of mylonitic thrust planes. Lateral shearing characterizes D₃, with development of macroscopic mylonites and mesoscopic conjugate shear zones. This was in response to a sinistral sense of movement, as indicated by prominent sub-horizontal extension lineations (L₃) and microscopic asymmetric augen structures. D₄ is deduced from stereograms and is indicated as cross-folding of F₃ fold axes. / Thesis (M.Sc.)-University of Durban-Westville, 1985.

Ce mémoire comprend trois parties qui ont été conçues pour pouvoir être lues indépendemment 1 ~ Géologie régionale et structurale, lithostratigraphie et tectonique. 2 - Etude pétrographique et géochimique de quelques formations gneissiques métamorphisrne et processus de remobilisation. 3 - Géochronologie.

1) INTRODUCCIÓEl massís del Canigó-Carançà forma part del conjunt de massissos gnèissics que d'una manera esglaonada es troben a la zona axial del Pirineu oriental i central. Està situat al vessant francès del Pirineu català, entre les comarques del Conflent i del Vallespir. Pel nord la vall de Tet constitueix el seu límit natural; a l'oest enllaça amb Cerdanya i el Capcir; a l'est les valls de la Lentilla i de l'Ample el separen de la plana del Rosselló, i pel sud la vall del Tec i els cims del Costabona i de Roca Colom el separen de l'alta vall del Ter (Ripollès).Com la resta de materials prehercinians de la zona axial, els gneiss del Canigó han sofert els efectes d'una complexa tectònica polifàsica herciniana, així com d'una sèrie d'aconteixements deformatius lligats a la tectònica alpina posterior. Presenta una megastructura braquiantiformal i està constituït fonamentalment per un conjunt de gneiss ocel.lars, amb característiques litològiques comparables a les dels gneiss que formen els altres massissos de la zona axial (L'Aston-Hospitalet, Mont-Lluís, Roc de Fraussa, L'Albera).2) OBJECTIUS l ESTRUCTURACIÓ DEL TREBALLL'objectiu fonamental d'aquest treball és el reconeixement i anàlisi, a diverses escales d'observació, del conjunt d'estructures de deformació que presenten els gneiss que formen la major part del massís, per tal d'establir la seva evolució estructural.A partir dels anys seixanta, i fins l'actualitat, el coneixement de l'estructura dels materials prehercinians del Pirineu, ha experimentat una sèrie d' avenços molt considerables. Ara bé, des dels treballs dels autors francesos, de finals d'aquesta dècada, no han estat massa nombrosos els estudis dedicats a l'anàlisi de la deformación en els massissos gnèissics del Pirineu oriental. La major dels treballs més moderns han dedicat l'atenció al reconeixement de les deformacions sobre imposades en els metasediments infrasilurians, o bé han estat consagrats a l'estudi de determinades estructures. Això plantejava la possibilitat de dur a terme un estudi dedicat específicamente a determinar les característiques de la deformació en un massís gnèissic. En aquest sentit, el massís del Canigó ofereix unes condicions immillorables, tan per l'existència d'una sèrie de treballs anteriors realitzats fonamentalment per G. Guitard i que forneixen una base fonamental per el coneixement del massís, com per la seva extensió i les condicions d'aflorament. Durant la realització d'aquest treball hem hagut de modificar encara que només lleugerament algun dels pressupòsits inicials. D'una banda la complexitat de les "deformacions postesquistoses" (en sentit ampli) en alguns sectors del massís, el fet d'haver centrat l'atenció en l'estudi d'una sèrie de qüestions fins ara poc treballades, i la utilització d'algunes tècniques de treball que requereixen una inversió de temps considerable i no proporcionen resultats fàcilment interpretables, han fet que qüestions com l'avaluació del tipus i del règim de deformació responsable de la formació de les diverses estructures planar s reconegudes, la comparació entre l'evolució estructural dels gneiss i la dels materials de la cobertora, o la determinació precisa de les transformacions mineralògiques que sofreixen els gneiss lligades als diversos aconteixements deformatius, no tinguin un tractament específic en aquest treball. Aquest conjunt de temes entrarien doncs a formar part de les nombroses qüestions encara pendents, i que requereixen el desenvolupament de treballs posteriors, probablement més selectius i no tan diversificats com el present estudi.Pel que fa al seu plantejament i desenvolupament, aquest treball està estructurat en tres parts fonamentals. A la primera (capítols II i III) es fa un breu repàs a l'estat actual de coneixements sobre els problemes que planteja l'estructura dels materials hercinians del Pirineu. Es fan també algunes consideracions prèvies sobre la terminologia i nomenclatura emprades, i sobre la problemàtica de les fàbriques del quars i la seva relació amb les estructures mesoscòpiques de deformació. A la segona part (capítols IV, V i VI) es descriuen les característiques de les diverses estructures de deformació reconegudes en els gneiss, a diverses escales d'observació, i es fa un intent de reconstruir la seva evolució estructural. A tall de comparació, i/o per establir determinades relacions cronològiques relatives, o per precisar les relacions amb els processos metamòrfics, es comparen les estructures dels gneiss amb les dels micasquistos o amb les d'altres roques deformades que formen part del massís. A la tercera part es discuteixen alguns dels resultats obtinguts ,i es fan algunes consideracions sobre els tipus fonamentals d'orientació cristal.logràfica preferent observats en els gneiss afectats pels diversos aconteixements deformatius.

Thesis (Ph. D.)--Carleton University, 1997. / Also available in electronic format on the Internet.

Made available in DSpace on 2015-03-26T13:53:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 771133 bytes, checksum: 78dfd152b2d14ccc58b07cf086ffda26 (MD5) Previous issue date: 2010-07-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Edaphic Oligochaetes acts in various fundamental processes, including maintaining soil fertility and soil quality in agroecosystems. However, agricultural practices, climatic conditions and soil characteristics affect populations of soil oligochaetes. Currently, as a result of problems with soil quality, water availability and plants, plus the high cost of agricultural inputs, it is necessary to find alternatives for sustainable use of land in agroforestry systems. Agroforestry systems with continuous input of organic matter and maintenance of crop residues on the soil surface provide biomass for oligochaetes, which acts positively on their population balance throughout the seasons. This study aimed to assess changes in populations of edaphic oligochaetes due to differences in the management of coffee (Coffea arabica) in the municipality of Araponga - MG. The study was conducted in agroforestry systems (SAFROM e SAFSAM), where coffee is intercropped with trees, in agroecological full sun coffee systems (PSAROM and PSASAM); conventional full sun coffee systems (PSACAR1; PSACAR2) and two forest fragments (FRAROM e FRASAM), used as references. PSA differs from SAF by not having trees intercropped with coffee. The collections of oligochaetes were performed in four treatments, at three depths (0 - 0.1 m, 0.1 - 0.2 m and 0.2 to 0.3 m), two times (February 2009 / January, 2010), and in five replicates 10 m equidistant from each in each area. Identification in the laboratory was at the level of genera and species. For each treatment, abundance of different species of oligochaetes found was estimated, and richness and Shannon s index was calculated. Statistical analysis was performed using Linear Mixed Effects models. There was not time effect and there was difference in depth. There was no effect of time but there was with depth, with the 0-10 cm depth having higher average abundances (52,3 ind/m2), followed by 10-20 cm depth (25,9 ind/m2). There was a significant interaction between depth and time. FRAROM had the largest number of oligochaetes (average of 224 ind/m2), but there were no differences between FRASAM,, SAFSAM and PSASAM (55,8 ind/m2) or between SAFROM and PSAROM (36,9 ind/m2). Practically no Oligochaeta were sampled in PSCCAR in, so this was not included in the statistical analysis. Pontoscolex corethrurus predominated in agroecosystems. The capacity for release of minerals during the vermicomposting process was evaluated using two types of rock (gneiss and steatite). The production of vermicompost, using catle manure, enriched with rock powder and without rock powder was performed in cylindrical plastic pots (2 dm3). The completely randomized design (DIC) used five replicates, of two different rock types (gneiss and steatite = G = E), at three doses (0,5 and 20%). An agronomic test was performed growing corn for 73 days in Oxisol, fertilized with vermicompost produced as previously described and only with rock powder (G or E). In total, we had eight treatments, controle (C, without rock poweder and vermicompost), Vc (only vermicompos, without rock powder), VcG5, VcG20, VcE5, VcE20, G and E. The completely randomized design had four replicates. Weekly, maize leaves were measured to assess growth. The plants performed better when the soil was fertilized with manure enriched with rock powder during the vermicomposting process. Oligochaetes can therefore be used as an indicator of soil recovery and may contribute to the recovery process, improving the availability of nutrients present in waste that can be used in agriculture. / Os Oligochaetas edáficos atuam em vários processos fundamentais para a manutenção da fertilidade e qualidade dos solos de agroecossistemas. As práticas agrícolas, condições climáticas e as características do solo afetam a população de oligochaetas edáficas. Atualmente, frente aos problemas como o decréscimo de qualidade do solo, da água e das plantas e o alto custo dos insumos agrícolas faz-se necessário buscar alternativas de uso sustentável das terras, como podem ser os sistemas agroecológicos, dentre eles os sistemas agroflorestais. Os sistemas agroflorestais, com aporte contínuo de matéria orgânica e qualidade e manutenção dos resíduos culturais na superfície do solo, propiciam maior biomassa das oligochaetas e atuam positivamente no equilíbrio populacional das mesmas, durante as estações do ano. Este trabalho teve como objetivo avaliar as alterações nas populações de Oligochaetas edáficos em função do manejo do café (Coffea arabica), no município de Araponga MG. O estudo foi realizado em áreas de plantio de café consorciado em sistema agroflorestal (SAFROM e SAFSAM); café a pleno sol agroecológico (PSAROM e PSASAM); café a pleno sol convencional (PSCCAR1) e (PSCCAR2); e dois fragmentos de mata (FRAROM e FRASAM) que foram utilizados como referências. PSAs diferem SAFs basicamente por não possuírem árvores consorciadas com o café. As coletas de oligochaetas foram realizadas, em quatro tratamentos, três profundidades (0 0,1m; 0,1 0,2m e 0,2 0,3m), duas épocas (fevereiro de 2009/ janeiro de 2010) e cinco repetições equidistantes em 10m, ao longo de uma linha de café, na mesma área. No laboratório, identificou-se os Oligochaetas no laboratório ao nível de gêneros e espécies. Para cada tratamento foi estimada a abundância das diferentes espécies de oligochaetas encontradas, riqueza e Índice de Shannon. A análise estatística foi feita utilizando Modelo Linear dos Efeitos Mistos (Programa R). Não houve efeito de época e houve diferença em profundidade. A profundidade de 0-10 cm apresentando a maior abundância, em média 52,3 ind/m2, seguida da profundidade de 10-20 cm apresentando, média de 25,9 ind/m2. Houve interação significativa entre profundidade e época. FRAROM apresentou o maior número de Oligochaetas (média de 224 ind/m2), não havendo diferenças (p<0,05) entre e FRASAM,, SAFSAM e PSASAM (55,8 ind m2) e entre SAFROM PSAROM (36,9 ind m2). Em PSCCAR praticamente não se encontrou oligochaetas e por isto não foi incluídos na análise estatística. Nos agroecossistemas avaliados ocorreu predomínio da espécie Pontoscolex corethrurus. A capacidade de solubilização de minerais durante o processo de vermicompostagem foi avaliada utilizando dois tipos de pó de rocha (gnaisse e esteatito) em 2 doses cada, com 5 repetições. A produção de vermicomposto com pó de rocha e sem pó de rocha foi realizada em potes plásticos cilíndricos (2 dm3), utilizando esterco de gado. O delineamento foi inteiramente casualizado (DIC), sendo o esterco enriquecido com pós de duas rochas diferentes (gnaisse = G e esteatito = E), três doses cada (0, 5 e 20 % m/m) e cinco repetições. Realizou-se um ensaio agronômico com a cultura do milho cultivada por 73 dias em Latossolo Vermelho Amarelo, fertilizado com os vemicompostos descritos e com apenas pó de gnaisse ou esteatito, totalizando oito tratamentos, sendo um controle (C, sem pós de rochas e sem vermicompostos), Vc (sem pós de rochas), VcG5, VcG20, VcE5, VcE20, G e E. O delineamento foi inteiramente casualizado com 4 repetições. Semanalmente a parte aérea do milho foi medida para avaliar crescimento. As plantas cresceram mais quando o solo foi fertilizado com esterco enriquecido com pó de rocha durante o processo de vermicompostagem. Os oligochaetas além de poder serem utilizados como indicadora de recuperação do solo, podem contribuir para o processo de recuperação, melhorando a disponibilidade de nutrientes presentes em resíduos que podem ser utilizados na agricultura.

Resumo: Os materiais empregados na pesquisa correspondem a rochas granulíticas, mais especificamente gnaisses enderbíticos. Exibem cor que varia de verde a cinza escuro, com textura de fina a média, e foliação que varia de pouco a bem marcada. Todos estes corpos rochosos estão dispostos sob a forma de maciços. Os materiais estudados foram denominados de Verde Netuno, Verde Santa Cruz e Verde Choró, respectivamente para os granulitos das regiões de Itapipoca, Granja e Chorozinho. Foram pesquisados quanto aos aspectos tecnológicos e alteração/alterabilidade quando em uso. O objetivo principal deste trabalho foi estudar as alterabilidades das rochas selecionadas e observar os seus comportamentos uma vez expostas à ação dos agentes de alteração em laboratório, em condições correlacionáveis às do ambiente em que poderão ser aplicadas. A resposta aos ensaios tecnológicos mostra que eles apresentam boa qualidade para uso ornamental e de revestimento. Os estudos de alterabilidade realizados em rochas granulíticas demonstraram que, mesmo rochas aparentemente pouco susceptíveis a alteração, podem apresentar problemas de degradação quando submetidas a ambientes poluídos quimicamente agressivos. Sobre estes aspectos, observou-se que as características petrográficas e os índices físicos (porosidade e absorção) são ferramentas muito importantes para a avaliação da durabilidade das rochas como materiais de revestimento. No contexto geral estas rochas mostraram-se bastante resistentes para uso como materiais de revestimentos. / Abstract: The materials employed in this research correspond to granulitic rocks, more specifically enderbitic gneisses. Those rocks exhibit of green to dark gray color, fine to medium texture and gentle to well-marked foliation. All of them constitute massif bodies. The denominations Green Netuno, Green Santa Cruz and Green Choró were given to the granulites of Itapipoca, Granja and Chorozinho, respectively. The research was carried out taking in account the technological aspects and weathering/weatherability when in use. The essential aim of this work is to study the alterability of selected rocks and to observe their behavior once exposed to alteration agents in a laboratory environment comparable to actual environments where these rocks are used. The results of the technological tests showed that these rocks present good quality for both ornamental and of coating use. The alterability studies conducted in granulitic rocks demonstrated that, even rocks with an apparent low susceptibility to alteration, may in fact problems when submitted to chemically aggressive polluted environments. On these aspects, it was possible to notice that both the petrographic characteristics and the physical parameters (porosity and absorption) are very important tools for the evaluation of the durability of the rocks as coating materials. Therefore, in a general context the rocks studied are quite resistant regarding both to the alteration capacity and to the technological characteristics. / Orientador: Tamar Milca Bortolozzo Galembeck / Coorientador: José de Araújo Nogueira Neto / Banca: Antenor Braga Paraguassú / Banca: Maria de Fátima Torquato / Banca: Fabiano Cabanãs Navarro / Banca: Antonio Carlos Artur / Doutor