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Dissertações em Geologia e Geoquímica (Mestrado) - PPGG/IG

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2604

O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA).

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Caracterização geológica, petrográfica e geoquímica de Granitos Arqueanos da Folha Marajoara, Terreno Granito-Greenstone de Rio Maria Sudeste do Pará
(Universidade Federal do Pará, 2009-07-08) DIAS, Samantha Barriga; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
During geological mapping in the Marajoara Sheet, located in the south portion of Rio Maria Granite-greenstone Terrane, southeastern of Amazonian Craton, three groups of Archean granites were distinguished: The Guarantã Suite, the Rancho de Deus Granite and Leucogranitic stocks. The first group is composed of three plutons, named Guarantã Granite (Gg), Azulona Granodiorite (GDaz) and Trairão Granodiorite (GDt), which are intrusive in the Arco Verde Tonalite and were assembled in the Guarantã Suite. The Rancho de Deus Granite is an oval stock, in contact with the Rio Maria Granodiorite and the Guarantã Granite, the latter contact being controlled by a regional shear zone. The third group is formed by small leucogranite bodies, intrusive in the Arco Verde Tonalite and Rio Maria Granodiorite. The epidote-biotite granodiorites to monzogranites of the Guarantã Suite display EW to NW-SE foliation and a porphyritic texture, with coarse alkali feldspar phenocrysts in a fine- to medium-grained matrix. The Rancho de Deus Granite is composed of hornblende-biotite monzogranites with a discrete foliation and porphyritic texture, displaying coarse alkali feldspar phenocrysts in a medium, even-grained matrix. The leucogranites are equigranular, medium-grained rocks. Geochemical data show that the Guarantã Suite and the leucogranites are dominantly peraluminous rocks, whereas the Rancho de Deus rocks vary from metaluminous to peraluminous granites. The three granite groups show strong geochemical contrasts. The Guarantã Suite is enriched in Al2O3, CaO, Na2O, Ba, Sr and Ga and impoverished in Fe2O3, K2O, MgO, Rb and Th compared to the Rancho de Deus Granite. On the other hand, the leucogranites are enriched in SiO2 and K2O and impoverished in Fe2O3, MgO, Na2O, CaO, P2O5, Ba, Sr, Zr, compared to the other two groups. The three groups exhibit moderate to strong HREE fractionation; the Guarantã Suite granites show only discrete negative or positive europium anomalies or are devoid of it. The europium anomalies in the Rancho de Deus Granite are discrete but always negative and those of the leucogranites are also negative but more important. The Rancho de Deus Granite and the Guarantã Suite rocks are similar geochemically to the Archean CA2 calcalkaline granites. However, the geochemical contrasts between these two groups cannot be explained by magmatic differentiation processes, because their rocks have similar SiO2 contents and display distinct trends in geochemical plots. Hence, the hypothesis of a genetic linking between these two granites is discarded and it is assumed that their magmas derived from different sources or evolved by different magmatic processes or both. A comparison between the three studied granite groups and similar Archean rocks of the RMGGR has shown that the Guarantã Suite rocks are similar to the granodiorites and monzogranites found in small satellite stocks associated with the Xinguara Granite pluton and with the Guarantã Granite, as originally defined by Althoff (1996). The Rancho de Deus Granite is similar to the Rio Maria Granodiorite and other rocks of the sanukitoid series. Finally, the leucogranites display petrographic and geochemical affinity with the Mata Surrão Granite. The large area of exposition and volume of the Guarantã Suite demonstrated that this variety of leucogranites was relevant in the evolution of the RMGGT and that, besides the Xinguara and Mata Surrão potassic calc-alkaline leucogranites, they should be considered as an important event of granitic magmatism in the RMGGT. This suite is better exposed in the Marajoara area, but similar rocks, alike those of the satellite stocks of the Xinguara pluton, were previously described and other similar rocks were probably mixed with the mentioned leucogranites in the past.
Acesso aberto (Open Access)
Estudo das relações de contato do granodiorito rio Maria com os granitos musa e jamon e com diques do proterozóico
(Universidade Federal do Pará, 1996-08-10) SOARES, Claudomiro de Melo; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
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Evolução petrológica e estrutural do gnaisse estrela, Curionópolis, PA
(Universidade Federal do Pará, 1991-12-18) BARROS, Carlos Eduardo de Mesquita; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Acesso aberto (Open Access)
Geologia e geoquímica do maciço granítico arqueano Xinguara e de sua encaixantes, sudeste do estado do Pará
(Universidade Federal do Pará, 1995-12-12) LEITE, Albano Antônio da Silva; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Acesso aberto (Open Access)
Geologia e petrologia da região central da Serra da Cordilheira-Goiás
(Universidade Federal do Pará, 1984-09-21) TEIXEIRA, Nilson Pinto; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
The area in focus was mapped at a scale of 1:100,000 and is located west of the city of Araguaína (Goiás) in a region located in the districts of Aragominas (formerly Pé do Morro) and Muricilândia and its surroundings. It is limited by the parallels of 7°00'00" and 7°25'23" of south latitude and by the meridians of 48°23'36" and 48°40'00" of west longitude, making a total of approximately 1395km². Geologically, it is located, for the most part, within the Araguaia Folding Belt. In this area occur the domic structures of Grota Rica and Cocalândia, in whose cores outcrop gneiss rocks, amphibolites and alkali-alumino-magnesian rocks, which constitute the Colméia Complex. These structures are similar to those previously described in the regions of Xambioá, Lontra, Colméia, Cantão, Rio Jardim and Rio Cunhãs, being enhanced by the quartzites and mica-schists of the Morro do Campo Formation. This gradually passes to mica-schists of the Xambioá Formation, which are the regionally dominant lithological types. The Xambioá Formation also contains, locally, amphibolite lenses. The set of constitutive rocks of the Morro do Campo Formation (lower) and Xambioá (upper) make up the Estrondo Group. Metamorphosed ultrabasic bodies occur locally, forming aligned hills with a submeridian disposition. These ultrabasic bodies, together with the units of the Estrondo Group, constitute the Baixo Araguaia Super Group. The Estrondo Group is covered to the east by sediments from the Pimenteiras Formation of the Parnaíba Sinéclise and to the west by Tertiary-Quaternary Covers. Among the gneiss rocks of the Colméia complex, trondhjemitic and granitic gneisses were identified, the former being largely dominant. In Trondhjemitic gneisses, two bands (1 and 2) have been described. Banding 1 has restricted occurrences and is folded in at least two deformation phases, with the first folding, absent in the other units, presenting orientation and relating to an older thermotectonic cycle (presumably from Archean), while the second with N-S orientation, it is related to the thermo-tectonic cycle that generates the constitutive rocks of the Baixo Araguaia Super Group (Upper Precambrian). Banding 2 is associated with this cycle, it is strongly penetrative, truncates locally and banding 1, presenting a parallel disposition to the axial trace (in plan) of the second fold. Banding 2 is generally shaped to domic structures. Associated with the first cycle (Archaean) and in agreement with the banding 1, there are quartz-feldspathic veins, apparently related to the oldest phase. There are also other quartz-feldspathic veins, sometimes concordant, sometimes discordant, with banding 2. Chemically, trondhjemitic gneisses almost always have a slightly variable composition, the same being true for granitic gneisses. Quartz-feldspathic veins concordant and discordant with banding 2 have their origin attributed to anathexic processes, which occurred at depth, during the second cycle (of the Upper Precambrian). These processes were partial and restricted, and allied to other factors, allowed the diapiric ascent of the gneisses of the Colméia Complex, whose lodging generated the domic structures, under metamorphic conditions equivalent to the average degree. In the Xambioá Formation, the dominant rocks - mica-schists - revealed, through their petrographic and chemical characteristics, a predominance, among the original sediments, of pelites and greywackes, with smaller contributions of carbonates. In the petrographic study, a close relationship was observed between the absence of garnet and the presence of epidote and vice versa, although there is incompatibility between them. Chemical analyzes showed that these relationships are controlled by the CaO content of each sample. When it exceeds a certain value, epidote crystallization is favored and garnet crystallization is inhibited, the opposite occurring in the opposite case. This compositional variation is observed even on a millimeter scale and is reflected in the area through the erratic distribution of the garnet, which makes it impossible to trace any isograde based on the appearance of this mineral. A similar phenomenon is observed in relation to staurolite, whose crystallization is only possible in rocks of adequate composition, a condition that is not satisfied by almost all the samples of the analyzed shales. In this case, the critical factor is the FeO content of the rock, which must be high to allow the formation of staurolite. The paragenesis present in the different lithological types of the Baixo Araguaia Super Group indicate that the metamorphism reached minimum conditions equivalent to the upper weak degree and maximum conditions consistent with the beginning of the medium degree, with a reasonably high pressure regime (5 to 6kb). The crystallization of garnet, epidote and staurolite was controlled by the composition of the original sediments. This fact was also observed a few kilometers to the north in the Xambioá region and a few kilometers to the south in the regions of Cantão, Rio Jardim and Rio Cunhãs. The structural study of the Baixo Araguaia Super Group allowed the characterization of at least five phases of deformations within a progressive deformation process, with the first four developed in a compression regime, generating different folds and inverse faults (?), while the latter developed in a stage of relaxation of efforts. A major accident is the Inverse Fault (?) of Aragominas of N-S orientation, which coincides with the Serra das Cordilheiras, which cuts the mica-schists of the Xambioá Formation, affecting them intensely. This unit outcrops both east and west of the escarpment, and it can be assumed that the other units have also been affected by the fault, although they are not exposed along the same current level of erosion. Other expressive lineaments with NNW-SSE and NNE-SSW orientations, better marked in the Xambioá Formation domains, also occur, some of which may correspond to directional faults along S2. From the interpretation of the data obtained and their integration with the existing ones, it is concluded that the geological evolution of the studied region was polycyclic, distinguishing different phases in each cycle.
Acesso aberto (Open Access)
Geologia e petrologia do extremo norte da Serra do Estrondo (GO)
(Universidade Federal do Pará, 1984-05-02) SOUZA, Antonio Celso Costa de; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Acesso aberto (Open Access)
Geologia, geoquímica e petrologia magnética do granito paleoproterozóico redenção, se do Cráton Amazônico
(Universidade Federal do Pará, 2001-06-29) OLIVEIRA, Davis Carvalho de; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Acesso aberto (Open Access)
Geologia, petrografia e geoquímica da associação tonalitotrondhjemito-granodiorito (TTG) do extremo leste do subdomínio de transição, Província Carajás
(Universidade Federal do Pará, 2013-07-31) SANTOS, Patrick Araujo dos; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
The eastern border of the Transition Subdomain of the Carajás Province is constituteddominantly of Archean tonalite-trondhjemite-granodiorite (TTG). Deformed monzogranites, similar to the Planalto granite suite, and metagabbros inserted in association mafic-enderbitic also occur. Paleoproterozoic isotropic granites and mafic dykes devoid of significant deformation crosscut the Archean lithologies. The TTGs are exposed as blocks or as flat outcrops in areas of low relief and commonly include quartz-diorite enclaves. The TTG rocks display gray colour and are generally medium-grained, showing compositional banding or, sometimes, homogeneous aspect. They show commonly a NW-SW to E-W trending foliation with vertical to subvertical dips and were submitted to NE-SW stress. Locally, it was identified a NE-SW foliation transposed to E-W along shear zones. In some instances, they exhibit mylonitic to protomilonitics features, registered in the oval form of plagioclase porphyroclasts or boudinated leucogranitics veins. Two petrographic varieties are recognized for this association: biotite-trondjhemite and subordinate biotite-granodiorites, both have similar mineralogical and textural aspects and are characterized by a poorly preserved igneous texture, partially overwritten by an intense recrystallization. EDS analyses revealed that the plagioclase is a calcic oligoclase (An27-19), with Or ranging from 0.6 - 2.3%. The biotites are ferromagnesian, with dominance of Fe over Mg (Fe / [Fe + Mg] ranging from 0.54 to 0.59) and the analyzed epidote presents pistacite contents ranging from 23 to 27.6 % and plot mostly in the range of magmatic epidotes. The trondhjemite shows all typical characteristics of Archean TTG suites. They have high La/Yb and Sr/Y ratios, suggesting they were derived from the partial melting of garnet amphibolite sources at high pressures (ca. 1.5 GPa) or, at least, that their magmatic evolution was controlled by the fractionation of garnet and possibly amphibole, without significant influence of plagioclase. The studied TTGs show similarities with Mariazinha tonalite and Mogno trondjemite, of the Rio Maria Domain, Colorado trondhjemite and, in at a lesser degree, to the Rio Verde trondhjemite, of the Carajás Domain. The granodiorites display a calc-alkaline signature and shows LILE enrichment, specifically K²O, Rb and Ba, when compared to the trondhjemites, but still preserving some geochemical features of the TTG. The geochemical data indicate that the trondhjemite and granodiorite are not related by fractional crystallization. An origin of the granodiorite by partial melting of the TTG rocks is also discarded. The granodiorite could, however, result of contamination of TTG magmas by lithosphere metasomatism or assimilation of sediments from subducted oceanic crust along trondhjemite liquid genesis. In the eastern portion of the mapped area, it was identified a small, E-W trending granite stock clearly controlled by shear zones. The rocks have mylonitic textures, characterized by ovoid-shaped feldspar porphyroclasts, wrapped by recrystallized quartz and mica. These granitic rocks have geochemical signatures of reduced A-type granites and are similar to the Planalto granite suite. Boulders of mafic rocks crop out locally in the northern portion of the area. These rocks show a dominant granoblastic texture, and are mainly composed of amphibole and plagioclase, with subordinate biotite and quartz. In the northern part of the mapped area, it was identified a body of isotropic granite without significant deformation and showing locally rapakivi textures. This granitic pluton was correlated to the Paleoproterozoic A-type granites, represented in the Carajás Domain by the Serra dos Carajás suite and Rio Branco Granite. These granites were not studied in detail. The geological and geochemical aspects shown by the Archean granitoids identified in the eastern part of the Transition Subdomain implies in the existence of significant TTG rocks in the Transition Subdomain. This reinforces the hypothesis that the Transition Subdomain could represent an extension of the Rio Maria Domain, but affected by crustal reworking events in the Neoarchean.
Acesso aberto (Open Access)
Geologia, petrografia e geoquímica do granito anorogênico Bannach, terreno granito-Greenstone de Rio Maria, PA
(Universidade Federal do Pará, 2005-03-24) ALMEIDA, José de Arimatéia Costa de; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
The Bannach Granite is intrusive in Archean rocks of the Rio Maria Granite -Greenstone Terrane, located in the eastern border the Amazonian craton. This Paleoproterozoic, elliptic, anorogenic granitic batholith is composed essentially of monzogranites with alkali feldspar, quartz and plagioclase as essencial minerals; hornblende, biotite and sometimes clinopyroxene as main mafic minerals; titanite, allanite, apatite, zircon, ilmenite and magnetite as primary accessory minerals; chlorite, sericite-muscovite, carbonate ± fluorite as secondary accessory minerals. Textural and mineralogical characteristics allow to recognize eight varieties of granite: coarse-grained facies bearing amphibole, biotite and sometimes clinopyroxene [cumulatic granite (CG), biotite-amphibole-monzogranite (BAMzG), and amphibole- biotite-monzogranite (ABMzG)]; porphyritic facies with biotite [porphyritic biotite-monzogranite (PBMz)] and leucomonzogranitic fácies [coarse -grained leucomonzogranite (CLMz), early and late medium - evengrained monzogranite (EMLMz and LMLMz) and fine- evengrained monzogranite (FLMz)]. The facies distribution within the batholith is zoned, with the less evolved facies (GC and BAMzG) situated along the border of the body and the more evolved ones in its central portion (LMLMz and CLMz). The Bannach batholith is subalkaline, metaluminous to peraluminous. K 2 O/Na 2 O ratios are between 1 and 2 and FeO t /(FeO t + MgO) between 0.86 and 0.97. The different facies have similar rare earth elements (REE) patterns, being enriched in light REE, slightly depleted in heavy REE and showing a negative europium anomaly that increases from the less evolved to the more evolved facies. The several facies of the Bannach granite plot in the within -plate granite field, as defined by Pearce et al. (1984) for Phanerozoic granites, and into the field of A -type granite, as defined by Whalen et al. (1987). They also show geochemical affinities with the ferroan granites of Frost et al. (2001) and with the A2-subtype (Eby 1992). All facies of the Bannach pluton display high magnetic susceptibility (MS), decreasing regularly from the facies carrying amphibole, biotite ± clinopyroxene (GC and BAMzG) to the leucogranites (EMLMz, CLMz, LMLMz and FLMz ). The different facies of the Bannach granite evolved through fractional crystallization of ferromagnesan minerals and feldspars. The differentiation trend was in the sense: BAMzG- ABMzG-PBMz-EMLMz-CLMz-FLMz. The LMLMz facies is interpreted as a separate intrusion
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Geologia, petrografia e geoquímica do Granodiorito Sanukitoide Arqueano Rio Maria e rochas máficas associadas, leste de Bannach-PA
(Universidade Federal do Pará, 2005) OLIVEIRA, Marcelo Augusto de; ALTHOFF, Fernando Jacques; http://lattes.cnpq.br/1004206862799097; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
New occurrences of the Archean Rio Maria Granodiorite (RMGD) situated to the east of Bannach town, immediately to the west of it’s type-area, in the Rio Maria Granite-Greenstone Terrain (RMGGT), southeastern Amazonian craton, were studied. The typical granodiorites, wich are dominant in the RMGD, include systematically mafic enclaves, as observed in other areas. However, in the studied area there are also mafic and intermediate rocks (IMR) with the RMGD. The Rio Maria Granodiorite is intrusive in the greenstone belts of the Andorinhas Supergroup. Field relationships between the RMGD and Archeans tonalites and trondhjemites (TTGs) are not conclusive being admitted that both have similar ages. Leucogranites correlated with the Xinguara and Mata Surrão Archean granites and the Paleoproterozoics Musa and Bannach granites of the Jamon Suite are intrusive in the RMGD. The dominant rocks of the RMGD are quite uniform, with, medium-to coarse-evengrained texture, and granodioritic or subordinate monzogranitic composition. The GDrm shows generally a gray color with greenish shades due to it’s strongly saussuritized plagioclase, white the monzogranites displays a rose gray color. The Rio Maria Granodiorite display generally a weak or striking WNW-ESE foliation due to mafic minerals and, sometimes, enclaves orientation. Two domains of IMR were identified: In the main domain, located near Bannach town, are exposed mostly quartz diorites and quartz monzodiorites; in the second domain situated in the center of the area, a minor occurrence of layered rocks was described. The dominant rocks in the larger body are mesocratic, dark-green, sometimes with rose tones rocks, with fine-to coarseevengrained texture. The layered rocks, interpreted as cumulatic rocks are inequigranular with a remarkable concentration of generally quadratic or short prismatic coarse amphibole crystals, enveloped by leucocratic intercumulus material. The RMGD and IMR rocks show similar textural and mineralogical aspects. The RMGD is formed dominantly by epidote-biotite-hornblende granodiorite (EpBtHbGd) with subordinate epidote-hornblende-biotite granodiorite (EpHbBtGd), and epidote-biotite-hornblende monzogranite (EpBtHbMzG). The mafic enclaves included in the RMGD are epidote-biotitehornblende diorites (EpBtHbDr) transitioning to monzodiorities. In the main mafic body epidotebiotite-hornblende quartz diorite (EpBtHbQzD) varying to epidote-biotite-hornblende quartz monzodiorite (EpBtHbQzMzD) are dominant. The layered rocks are enriched in mafic minerals, mostly amphibole, compared to monzodiorites and granodiorites. The RMGD and IMR follow the calc-alkaline series trend in some diagrams. However, they display lower Al2O3 and CaO and larger MgO, Cr and Ni contents compared to calc-alkaline series, approaching geochemically the sanukitoids series. The patterns of rare earth elements of different rocks are similar, with pronounced enrichment in light rare earth elements (LREE) and strong to moderate fractionation of heavy rare earth elements (HREE) (La/Ybn=11,92 a 44,38). However, the (La/Yb)n ratio is lower in the EpBtHbQzD and EpBtHbQzMzD (La/Ybn=17,20 a 22,81), compared to the RMGD (La/Ybn=15,52 a 44,38). Compared to the RMGD and IMR, the layered rocks are relatively enriched in HREE (La/Ybn=11,92 a 14,37), probably in response to amphibole accumulation. The RMGD and IMR display some geochemical affinities, but also significant difference, and are interpreted as cogenetic but not comagmatic rocks. Geochemical data show that there is a ompositional gap between both the RMGD and IMR and the layered rocks and mafic enclaves, suggesting distinct processes for the origin of the latter group of rocks. Field aspects and petrographic and geochemical caracteristics denote that the RMGD and IMR are cogenetic rocks. However, geochemical data suggest that the intermediate rocks and the RMGD are not related by a fractional cristalization process. The wide distribution of granodiorities and relatively local occurrence of do not also favor this hypothesis. It is concluded that the intermediate rocks derived from similar sources than those of RMGD, but probably result of a higher degree of melting, being both cogenetic, but not comagmatic rocks. The layered rocks are genetically related to the sanukitoid association, but they had a particular magmatic evolved involving participation of crystal accumulation processes.
Acesso aberto (Open Access)
Geologia, petrografia e geoquímica do Trondhjemito Mogno e rochas arqueanas associadas, Terreno Granito-Greenstone de Rio Maria - SE do Pará
(Universidade Federal do Pará, 2009-07-15) GUIMARÃES, Fabriciana Vieira; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Geological mapping alongside petrographical and geochemical studies in the occurrence area of the Mogno Trondhjemite in the Rio Maria Granite Greenstone Terrain (RMGGT) led to the identification of two distinct TTG facies. The Mogno Trondhjemite designation was maintained for the dominant facies with NW-SE to E-W structural style and distributed over east and west through the mapped area. The association identified on the central-west portion of the area, with NE-SW and N-S dominantly foliation was defined as a new stratigraphic unit called Mariazinha Tonalite. In the mapped area it was also possible to individualize another unit, the Grotão Granodiorite which intrudes Mariazinha Tonalite and it was proposed the redefinition of Parazônia Tonalite which now is to be called Parazônia Quartz-diorite. Geochronological data (Almeida in prep.) revealed that Mogno Trondhjemite and Mariazinha Tonalite are not part of the second generation of TTG rocks from the RMGGT because they yield ages older than 2.87 Ga. Also, the Parazônia Quartz-diorite is similar in age with the sanukitoid association of the RMGGT. Mogno Trondhjemite and Mariazinha Tonalite are mainly composed by quartz and plagioclase with biotite and magmatic epidote as the main ferro-magnesian minerals. Their geochemical characteristics are compatible with Archaean TTG granitoids with high Al2O3 contents, relatively poor in ferromagnesian elements and display ETR patterns with moderate to strong fractioning of ETRP and smooth Eu anomalies. The Grotão Granodiorite is a leucogranite composed by plagioclase, quartz and potassic feldspar with biotite and epidote as the main ferromagnesian minerals. This leucogranite has metaluminous to peraluminous character and has a distinct geochemical behaviour in comparison with RMGGT TTG granitoids and the Xinguara Granite (Leite 2001, Leite et al. 2004). In K-Na4 Ca digrams the Grotão Granodiorite escapes from the trondhjemitic trend as it shows enrichment in K in relation to TTG granitoids, but with minor K contents related to the Xinguara Granite and the biotite-granodiorite studied by Medeiros (1987). Parazônia Quartz-diorite shows compositions varying from quartz-diorite to granodiorite. The Parazônia Quartz-diorite is very similar to the sanukitoid rocks from the RMGGT (Oliveira et al. 2006, 2009), even though the Parazônia Quartz-diorite also displays some remarkable differences in relation to Bannach intermediate rocks, such as minor values of silica and Mg#.
Acesso aberto (Open Access)
Geologia, petrografia e geoquímica dos diques da região de Rio Maria, SE-PA
(Universidade Federal do Pará, 1996-09-09) SILVA JÚNIOR, RENATO OLIVEIRA DA; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
In the region of Rio Maria, SE of Pará, several dykes were mapped, mainly intrusive in the Granodiorite Rio Maria (GdRM) and, subordinately, in the anorogenic granite Musa (GM). Forming small elongated ridges that stand out in the morphology with a positive relief, arranged mainly according to NW-SE and E-W trends and, subordinately, N-NE. The maximum width of these bodies is 30 m, and they have an outcropping length of 1,500 to 2,000 m, reaching 3,000 m. Five groups of dykes were identified petrographically: diabases, diorites, quartz-diorites, dacites and rhyolites. The transverse and longitudinal profiles in the direction of these bodies show a decrease in rock granulation, in the center-edge direction of the body, usually culminating in aphanitic rocks, which represent, as a rule, the cooling edge of the dyke. Close to these edges, enclaves and tonsils filled with quartz-feldspathic material are frequently observed. The contacts with its host country are abrupt, sometimes marked by the presence of cooling edges, whose thickness varies from a few centimeters to, exceptionally, 2 m. The K-Ar ages of these dykes are: (1) 700 ± 8 Ma in qz-diorite (whole rock); (2) 883 ± 10 Ma in diorite (plagioclase); (3) 1,099 ± 39 Ma in diabase (plagioclase); (4) 1,802 ± 22 Ma in diabase with olivine (mafic concentrate). The first three ages are interpreted as minimum ages for these bodies. The age of 1,802 ± 22 Ma is compatible with the age of 1,707 ± 17 Ma (Rb-Sr in RT) obtained for dacites and porphyry granites. The geochronological data available for the dikes in the Rio Maria region allow placing them in the Proterozoic, and the most reliable ages suggest that at least part of these dikes is contemporary with the anorogenic granitic magmatism. Diabases have been divided into four subtypes: (1) diabase with olivine - exhibits subophytic texture. It consists of labradorite (An55-65), augite + pigeonite, olivine, opaques and hornblende; (2) porphyritic microdiabase - cuts diabase with olivine, formed by plagioclase phenocrysts immersed in a pilotaxitic matrix formed by plagioclase, augite, opaque and amphibole slats; (3)) amphibole-diabase- exhibits a granular texture with a subphytic tendency, is made up of labradorite (An54-64), opaque minerals augite, late amphibole (tremolite-actinolite) and, rarely, hypersthene; (4) auginite-diabase (RJ-18B) with ophitic texture, it is formed by labradorite (An56), augite, opaques and, secondary amphibole. Diorites and quartz-diorites show, in general, a granular texture tending to subphytic or porphyritic with a matrix rich in granophyric intergrowths. Diorites are formed by very saussuritized plagioclase, augite, quartz, hornblende and opaques. Quartz-diorites have similar mineralogy to diorites, differing only in the modal content of quartz and granophyric intergrowths. Some diorites and diabases present plagioclase phenocrysts with sieve texture, suggesting the action of mixing and/or mingling processes. The dacites are formed by porphyry dacites and porphyry dacites rich in mafics. Both have a porphyritic texture, locally glomeroporphyritic, formed by aggregates of plagioclase phenocrysts, quite saussuritized, hornblende locally involving augite, in addition to isolated quartz phenocrysts. The two subtypes have a predominantly granophyritic matrix, sometimes spherulitic. The presence of microcrystalline quartz was noted forming almond-shaped aggregates (spots), attributed to mixing processes. The rhyolites exhibit a porphyritic texture, locally glomeroporphyritic, formed by plagioclase and quartz phenocrysts, immersed in a microcrystalline matrix with a micrographic tendency. Microcrystalline aggregates consisting of chlorite, biotite and opaques also occur. The TAS diagram shows good correlation between the modal classification and the geochemical data. In this diagram the diabases and diorites plot within the field of their volcanic counterparts. Quartz-diorites generally fall into the field of low-silica dacites. The dacites themselves are a little richer in silica than the preceding group, although both focus on the same field. In the AFM diagram the samples are located in the tholeitic subalkaline field. The presence of compositional gaps between groups, mainly between diabases and diorites, and from these to quartz-diorites, reinforces the hypothesis that these rock groups studied do not present a continuous magmatic evolution. The RJ-18B sample, although presenting characteristics of diabase, shows geochemically greater affinities with the diorites. The geochemical data also reinforce the hypothesis that the dikes of Rio Maria, although showing a tholeitic affiliation, were probably generated from different liquids, since the compositional gaps between the various groups are very accentuated. The dacites, although they present, in some diagrams, an overlap with the quartz-diorites, they differ from them petrographically and geochemically, too, and, in terms of occurrence in the field. There is petrographic evidence that the crystallization of diabases was driven mainly by the fractionation of olivine, while in diorites, augite and plagioclase played a dominant role. The petrographic and geochemical data show that the diabases, with the exception of sample RJ-18B, are entirely different from the other groups in terms of magmatic evolution. Diorites and quartz-diorites, in turn, although petrographically similar, present a compositional gap that weakens and immediate hypothesis since the latter represents a more evolved term, derived from the former. Sample RJ-18B is interpreted as a mafic concentrate of these diorites. This hypothesis can be justified by the modal and chemical composition of this sample. Dacites and rhyolites are probably genetically linked to anorogenic granitic magmatism, with probable associated mixing processes, mainly in the case of dacites.
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Geologia, petrografia e geoquímica dos granitoides arqueanos da área de Vila Jussara, Província Carajás
(Universidade Federal do Pará, 2012-12-03) SILVA, Alice Cunha da; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Geological mapping, followed by petrographic and geochemical studies, conducted near Vila Jussara, locality situed south of Canaa dos Carajas, in the Transition Subdomain of the Carajas Province, allowed significant advance in the characterization of Archean granitoids previously embraced in the Xingu Complex. The oldest unit identified in the area is a hornblende-biotite tonalite of Mesoarchean age (~2.93 Ga) named Sao Carlos Tonalite. It is followed stratigraphycally by a Mesoarchean (~2.87 Ga) tonalitic-trondhjemitic-granodioritic association (TTG, Colorado Trondhjemite) and by a Leucogranodiorite of undefined age but distinct from those associated with the Colorado Trondhjemite. Additionally, in the study area, Neoarchean granitoid bodies (ca. 2.74 to 2.73 Ga, tonalites to granites), previously correlated to Planalto Suite and informally designated here as Vila Jussara Granitoids, were also mapped. Mafic dikes are intrusive in the Archean granitoids. The Sao Carlos Tonalite and Colorado Trondhjemite constitute the main goal of this research and, therefore, are discussed in more detail. The Leucogranodiorites and the Vila Jussara Granitoids are characterized in a more succinct way because they are being studied by other researchers. In this case, the aim was to make a preliminary characterization of these granitoids and compare them with the two studied tonalitic units. This was particularly relevant in the case of the Vila Jussara Granitoids because they have tonalitic to granodioritic varieties that could be confused with the rocks of the two tonalitic units. The Sao Carlos Tonalite has a dominant N-S foliation discordant with the E-W regional trend, is composed of amphibole-biotite tonalite, and shows a remarkable recrystallization of plagioclase and quartz. It yielded an age of ~2.93 Ga (Pb-Pb zircon evaporation; Guimaraes in preparation) and is depleted in silica and enriched in TiO2, MgO, Fe2O3t and CaO compared to the Colorado Trondhjemite. The Sao Carlos Tonalite displays relatively low (La/Yb)n and discrete negative Eu anomalies. Its geochemical characteristics are distinct of those of typical Archean TTG suites, and also of the Rio Maria Sanukitoid Suite. On the other hand, the Sao Carlos Tonalite show strong geochemical contrast with the Bom Jardim Trondhjemite and Pedra Branca suite and significant analogies with the amphibole-bearing varieties of the Campina Verde tonalitic complex of the Canaa dos Carajas area in the northern part of the Subtransition Subdomain of the Carajas domain. The Colorado Trondhjemite shows compositional banding and E-W to NW-SE or, locally NS, foliation with strong dips. It is composed of epidote-biotite tonalite/trondhjemite with subordinate granodiorite. Its rocks show intense recrystallization which affected mainly the plagioclase and quartz crystals. Their geochemical characteristics are consistent with those of typical Archean TTG suites. The heavy REE are strongly fractionated [high (La/Yb)n] and some samples show positive Eu anomalies and others absence of Eu anomaly or discrete negative Eu anomalies. An age of ~2.87 Ga (Pb-Pb zircon evaporation) was obtained for this granitoid. The Leucogranodiorite exhibit a dominant E-W foliation and, besides quartz and feldspars, have biotite, epidote and muscovite as main minerals. Most rocks are porphyritic with coarse- or medium-grained phenocrysts or phenoclasts of plagioclase and alkali feldspar in a fine-grained recrystallized matrix. This unit is better exposed immediately to the east of the mapped area, where it is being studied in greater detail. Geochemical data of these rocks indicate its distinct character compared to the granodiorites of the TTG association (Colorado Trondhjemite). The Vila Jussara Granitoids are intrusive in Sao Carlos Tonalite and Colorado Trondhjemite and form E-W elongated bodies in the central part of the study area. Granites (stricto sensu) are dominant in this unit which includes also granodiorites and tonalites. The granites were not included as a goal of our study but the latter rocks were studied because of the relevance of a clear separation between them and the studied Mesoarchean granitoids with the same petrographic classification. Petrographic and geochemical data show that the granodiorite and tonalite associated with Vila Jussara Granitoids are distinct from those found in the Sao Carlos Tonalite and Colorado Trondhjemite. This conclusion was corroborated by several Neoarchean ages obtained in representative granodiorites and tonalites of the Vila Jussara granitoids (2.75 to 2.72 Ga, Pb-Pb zircon evaporation; Guimaraes in preparation). Keywords: Stratigraphic geology – Archean. Carajas Province. Transitional Subdomain. TTG. Granitoid.
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Geologia, petrografia e geoquímica dos granitóides arqueanos de Sapucaia - Província Carajás-PA
(Universidade Federal do Pará, 2013) TEIXEIRA, Mayara Fraeda Barbosa; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
Geological mapping performed in the eastern portion of the Transition Subdomain, Carajás Province, southern of Canaã dos Carajás and the northern of Sapucaia cities, allowed the identification, individualization and characterization of a variety of Archean rocks, previously encompassed in the Xingu Complex. The oldest unit identified in this area is a hornblende tonalite, correlated to São Carlos Tonalite (~2.93 Ga), which is exposed as blocks or outcrop and commonly present foliation (NW-SE to E-W) or homogeneous aspect. Its geochemical signatures differ from the typical Archean tonalite-trondhjemite-granodiorite (TTG) associations due to show enrichment in TiO2, MgO and CaO, low contents of Sr, and Rb contents similar to samples with lower concentrations of silica, which are reflected in higher Rb/Sr ratios and lower Sr/Ba ratios. The REE patterns reveal low to moderate fractionation of HREE compared to LREE, and discrete or moderate negative Eu anomalies. It is stratigraphycally followed by TTG association correlated to Colorado Trondhjemite (~2.87 Ga) which displays gray color, medium-grained, and commonly a NW-SE to E-W foliation. In the southern of area, outcrops a body of 40 km 2, which comprises a small mountain of porphyritic leucogranodioritic rocks named Pantanal Leucogranodiorite . It is emplaced at TTG association and crosscutted, on its western portion, by deformed leucogranites. The Pantanal Leucogranodiorite shows peraluminous character and calc-alkaline affinity, with high contents of Ba and Sr. The REE patterns show nosignificant Eu anomalies and HREE are strongly fractionated, which is geochemically similar to Guarantã Suite (~2.87 Ga) from the Rio Maria Domain. Its origin may be related to low degrees of melting of TTG, probably accompanied by interaction with fluids enriched in K, Ba and Sr, derived from a metasomatized mantle. The leucogranites exhibit A-type geochemical signature and reduced character, and may have originated from the melt of dehydrated peraluminous calcic-alkaline rocks, during the Neoarchean. In the eastern portion of the Pantanal Leucogranodiorite was also identified ahornblende-biotite monzogranite which is geochemically similar to oxidized A-type granites, correlated to Neoarchean Vila Jussara Suite. Also, it correlated to Neoarchean subalkaline magmatism in the northern area, occur two granitic stocks. They comprise (i) tonalite to granodiorite with geochemical signature similar to oxidized A-type granites and show affinity with Vila Jussara Suite; and (ii) monzogranites which show reduced A-type granites signature and could be compared to Planalto Suite. At northern of the study area was identified an association of mafic-enderbitic rocks which comprises intensely deformed and recrystallized hornblende norite, pyroxene-hornblende gabbros, pyroxeneix hornblende monzonite, hornblende gabbros, amphibolites and enderbites, which are represented in the geological map as a WNW-ESE small elongated body , and a semicircular body controlled by shear zones. The textures observed in these rocks indicate that recrystallization occurs under relatively high temperatures, 6000C or above, and those rocks show metamorphic features. The geochemical behavior of these rocks suggests that the hornblende-norite, hornblende-gabbros and amphibolites are tholeiitic subalkalines, whereas enderbites, pyroxene-hornblende gabbro and pyroxene-hornblende monzonite exhibit calcalkaline signature. The low La/Yb ratios for mafic rocks indicate low degree of fractionation, whereas the high La/Yb ratios for enderbites reveal significant fractionation of HREE during formation and differentiation of its magmas, and the concavity of HREE pattern indicates probably influence of amphibole fractionation during its evolution. In the central and northcentral of area was recognized biotite-monzogranites with peraluminous and calc-alkaline signature and distinct REE patterns, which allowed us to distinguish two groups. The first shows higher REE enrichment, weak enrichment in LREE relative to HREE, and exhibit moderate negative Eu anomalies, indicating no significant fractionation of phases enriched in HREE and show possibly affinity with Bom Jesus Granite from Canaã dos Carajás area. The second group shows a sharp fractionation of HREE relative to LREE, with discrete or absent Eu anomalies, and concave HREE patterns indicating that amphibole was important phase during the fractionation of these rocks, like Serra Dourada and Cruzadão granites, also located in the Canaã dos Carajás area. This comparison should be enhanced as soon as further geochemical and geochronological data are available in order to a correlation can be evaluated.
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Geologia, petrografia e geoquímica dos granitóides de Canaã dos Carajás, SE do estado do Pará
(Universidade Federal do Pará, 2003-10-11) GOMES, Alan Cardek Brunelli; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
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Geologia, petrologia e geoquímica dos granitóides cálcico-alcalinos da região de Portovelo-Zaruma, El Oro-Equador
(Universidade Federal do Pará, 1996-07-30) LOYOLA PAZ, Jorge Eduardo; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
In the Portovelo-Zaruma region, southwest Equator, occidental side of Cordillera Occidental of the Equatorian Andes, were mapped, at 1: 60.000 scale, five granite bodies: El Prado, Guayabo-Porotillo, Ambocas, Rios Luis-Ambocas anda Amarillo-Pindo. The other geological units are the Paleozoic Tahuim Group, composed by the San Roque Formation (quartzites, schists, gneisses, migmatites and amphibolites) and the Capiro Formation (quartzites, schists and phyllites); the Cretaceous Celica Formation (basalts and andesites), folded and discordantly overlay by Tertiary pyroclastics and andesitic flows. The granite bodies outcrop in very close areas, and probably are part of a unique batholith, only discontinuously exposed by the erosive processes. The granites are not dated, and are supposed to be of Triassic to Cretaceous age. The El Prado Granite intrude the Capiro Formation. It shows a elongated shape in the NW-SE trend (10 x 3 km). The Guayabo-Potillo Granite cuts the Tahuim Group, also showing an elongated shape in the NW-SE trend (7 x 3 km). The Ambocas Granite shows a near circular shape small bodies, and intrude the San Roque and Capiro formations, respectively. The relationships between all these granites and the Celica Formation are not conclusive due to the inaccessibility of the contact zones or by the fact that they are covered by colluvial deposits. The modal compositions of the granites shows span a expanded range, including gabbros, quartz gabbros, quartz diorites, tonalites, granodiorites and monzogranites. In the QAP diagram the rock follow preferentially the calc-alkaline tonalitic trend, but some granodiorites and monzogranites display a calc-alkaline granodioritic trend. Two rock groups were distinguished: (a) mafic to intermediate mafic-rich rocks - gabbros, quartz gabbros and quartz diorites; (b) felsic granitoids rocks - tonalites, granodiorites, and monzogranites. The dominant mafic minerals of the (a) group are pyroxenes, amphiboles and biotite, and biotite in the (b) group. The felsic rocks of the Guayabo-Porotillo body commonly show primary muscovite, are quartz-rich, and were affected by a strong hydrothermal alteration. Muscovite is also relatively abundant in the granitoids of the Ambocas, Luis-Ambocas rivers and Pindo-Amarillo rivers bodies. Amphibole is an important phase only in some granitoids of the El Prado body. The textures of the mafic and intermdiate rocks are porphyritic, pilotaxitic or seriated. Locally the plagioclase shows sieve texture. The felsic rocks are not deformed, and display a medium grained hypidiomorphic texture. According to the geochemical data about these granites there is a compositional gap between the mafic/intermediate and felsic rocks. Nevertheless, the studied rocks, fit the calc-alkaline trend displayed by the continental arc plutonic magmatism of the Andean chain. The mafic rocks are metaluminous and the amphibole-bearing felsic rocks are weakly metaluminous. The muscovite-bearing rocks are strongly peraluminous. A deep compositional gap between the two sets is clearly seen. In the diagram Ca+alkalis vs. SiO2 the rocks plot in the normal arc-related calc-alkaline granites field. However, some samples do not follow the general trend, probably due to crustal contamination or hydrothermal alteration. The El Prado rocks are less disturbed, following a trend very similar to that dis played by New Guinea Series or by the late granodiorites of Panama. The trace elements contents are similar to that of the volcanic arc granites (VAG). The metaluminous granites are petrographic and geochemically very similar to the I-type granites, but their tectonic enviroment is close to that of the Cordilleran I-type granites. The peraluminous granites, at a first sight, are similar to the S-type granites Australian granites, but are not cordierite-bearing, an index mineral of the Australian S-type granites. To explain the constrasting aspects between the metaluminous and the strongly peraluminous granitoids, it is proposed the hypothesis that the latter are derived from an I-type magma, contaminated by metasedimentary crustal rocks, by an assimilation process, similar to that described in the SW of USA. Other hyphotesis, considered more specifically for the extremely peraluminous granitoids, are: (a) their derivation from sedimentary sources; (b) a leaching of alkalis related to strong subsolidus hydrothermal processes, modifying the primary igneous compositions.
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Maciço granítico Musa: mapeamento, petrologia e petroquímica, Rio Maria, SE do Pará
(Universidade Federal do Pará, 1987-07-01) GASTAL, Maria do Carmo Pinto; DALL'AGNOL, Roberto
The Musa granitic massif, located in the extreme-southeast of the state of Pará (southern portion of the Mineral'de Carajás Province), is a permissive intrusion, placed in shallow crustal levels. It cuts rocks from the regional basement, formerly included in the Xingú Complex, including the Rio Maria granodiorite, the Pedra Preta greenstone belt type sequence and the Archean gneisses. Pre-existing faults and fractures played an important role in placing the massif. There are important wolframite mineralizations in quartz veins, adjacent to the granite, where it cuts the greenstone-like sequence, in the Pedra Preta area (to the west). Its origin is due to the thermometamorphic reworking of the W contained in the rocks of the greenstone sequence, at the time of the intrusion of the Musa massif. The contact relationships with the host regions reveal a high viscosity contrast between the granitic magma and the same, and that conditions of medium degree metamorphism and pressures below 4 kbar were reached. The faciology of the massif includes leucocratic to hololeucocratic biotite granites, containing amphibole and titanite, which were divided into monzogranites and syenogranites, and intermediate and acidic hypoabyssal rocks (microdiorites, porphyry dacites and porphyry granites). The relationships between the different facies indicate that the monzogranites are the most precociously placed, being cut by the dykes and both, in turn, truncated by the syenogranites. In monzogranites, the existence of enclaves of monzo to granodiorite composition is common, interpreted as crystalline residues carried in equilibrium by the magma. Texture and mineralogical variations observed in the two groups of granitic facies allowed us to subdivide them into seven distinct petrographic facies: Biotite-amphibole monzogranite, amphibole-biotite monzogranite, biotite-monzogranite, leucomonzogranite, amphibole-biotite syenogranite, leucosyene-granite and microsyenogranite. Some granitic rocks that occur associated with the mineralized veins of Pedra Preta resemble heterogranular leucosyenogranitic facies, laughing because they are more intensely transformed by late-magmatic events. The different granitic facies exhibit sub-alkaline composition, are calc-alkaline, metaluminous to slightly peraluminous and are relatively enriched in Si02, K20, FeO(t), Ti02, P205, Ba and Y and depleted in MgO. Together, they show greater analogies with the Cordilleran granites (type I - Chappell and White, 1974) or the Magnetite series (Ishihara, 1981), although the terms of hololeucocratic syenogranites differ a little from the others. According to the classification by Pearce et alii (1984) , they are classified as intraplate granites, developed in attenuated continental crust. The behavior of the trace elements does not characterize the different facies as metallogenetically specialized granites, however some samples of microsyenogranites can be seen as such. Geochronological data, Rb/Sr in T.R., obtained for the different facies present in the Musa massif, although not entirely conclusive, seem consistent with the observed order of placement. On the other hand, the given age, taking the set of samples from the various facies, is 1692 ± 11 Ma and R.I. 0.78777 : 0.00023. This age shows that this massif is not related to the Uatumã event, bringing it closer to the Jamon massif intrusion (1601 ± 21 Ma). The chemistry of the hypoabyssal rocks does not confirm their relationship with the volcanic ones of the Uatumã group. The "trend of tholeiitic affinities" in the AFM diagram, presented by the set of samples from the massif differs from that of the "calci-alkaline" of the Uatumã volcanoes. The spatial and temporal proximity between the Musa and Jamon massifs and the presence in them of very similar monzogranitic facies leads to the interpretation that they originated and evolved through analogous processes. This allows the definition of Acidic and Intermediate Magmatism of Rio Maria from the Middle Proterozoic (1700-1600 Ma), including the two massifs, intermediate and acidic hypoabyssal rocks and Marajoara granite. The dataset confirms the cogeniticity of the various facies occurring in the massif, but reveals possible variations in the source rocks. , which would be mixed. The expansion of partial melting processes led to the inclusion of more superficial rocks, related to volcanic sedimentary sequences. This model, coherent with the ideas of Hildreth (1981), reveals the existence of, at least, two slightly different magmatic liquids (monzogranitic and syenogranitic), formed at different depths of the crust and which would have evolved independently, but through of prolonged fractional crystallization processes. Regarding the tectonic environment at the time of generation of the Musa massif, the data leave doubts as to whether it is an intraplate, anorogenic granite or whether it is related to a Proterozoic continental margin.
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Mapeamento e petrologia do granito Mata Surrão: um exemplo de granito “Stricto Sensu” arqueano
(Universidade Federal do Pará, 1992-07-25) DUARTE, Kennedy Dantas; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
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Minerais óxidos de Fe e Ti e suscetibilidade magnética em vulcânicas e granitóides proterozóicos da Vila Riozinho, Província Aurífera do Tapajós
(Universidade Federal do Pará, 1999-12-22) FIGUEIREDO, Marco Aurélio Benevides; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
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Petrografia e geoquímica do Granito Pojuca, Serra dos Carajás-PA
(Universidade Federal do Pará, 1998-06-14) HORBE, Marco Antonio; DALL'AGNOL, Roberto; http://lattes.cnpq.br/2158196443144675
The Pojuca Granite outcrops in the northern portion of the Serra dos Carajás, showing intrusive contact with the Archean rocks of the Itacaiúnas Supergroup. The petrographic studies, based on drilling cores, revealed that in the studied portion (sub-outcrop) the body is constituted by monzogranites (MzG), dominant, with variations for monzo and syenogranitic (MzSG) transitional terms, occurring subordinately amphibole-granitoids, alkali -feldspar-granites, pegmatoid rocks and hydrothermalized leucogranites. The rocks are, in general, isotropic, equigranular medium to coarse, pink, very poor in mafics (chlorite±amphibole±tourmaline <7%), constituting leucocratic to hololeucocratic varieties, with very localized brittle deformation. The monzogranites and the monzo to syenogranites are very similar petrographically, however they present different geochemical behavior, marked by the enrichment in K2O and depletion in Na2O in the rocks of facies of the MzSG in relation to the MzG. The amphibole-granitoids show petrographic and chemical characteristics that indicate a hybrid origin, while the alkali-feldspar-granites are related to hydrothermalized portions and occur very locally. The leucogranites (LG) are restricted to the southeast end of the granite and have a well differentiated mineralogical, petrographic and geochemical behavior in relation to the other studied facies. They represent the granite dome, in sharp lower contact with MzG and MzSG, with evidence of being precocious in relation to the other facies, having been fragmented during their placement. LG are medium and fine-grained rocks, pink to cream in color, locally gray or greenish, hololeucocratic (M<2%), being hydrothermalized to varying degrees. Petrographically, two subfacies are distinguished, individualized based on the intensity of the transformations: leucogranites (LG) and intensely hydrothermalized leucogranites (LGIH). Despite the difficulties in distinguishing between primary (magmatic) albite and decalcified plagioclase, which also have an albitic composition, it was concluded, based on petrographic and geochemical evidence, that leucogranites are effectively albite-granites, assuming the hypothesis of their magmatic origin. From the remarkable coincidence of ages between the Pojuca Granite and several anorogenic granites from the Eastern Amazon and the other existing similarities between them, the Pojuca Granite was compared with the Jamon, Musa, Cigano and Serra dos Carajás granites. In terms of modal composition it does not differ from the other granites, however the leucogranites (albite-granites) present in the Pojuca Granite represent a particular variety, which was not registered in the other bodies. The Pojuca Granite exhibits intraplate type A geochemical characteristics and similarities with several anorogenic granites from the Eastern Amazon. Among those chosen for comparison, their greater affinity with the Serra dos Carajás and Cigano granites and the existence of clear differences in relation to the Jamon and Musa granites are clear. Therefore, the existence of geochemical contrasts between the anorogenic granites of the Rio Maria Granite-Greenstone Terrain (TGGRM) and those of the Carajás Block (Pojuca, Serra dos Carajás and Cigano) are confirmed. The albite-granite identified in the Pojuca Granite differs in mineralogical, petrographic and geochemical terms from the other albite-granites described in the Amazon, but this comparison should be deepened in view of the economic and petrological importance that these rocks have.