Norberto Dani

Universidade Federal do Rio Grande do Sul | UFRGS · Centro de Estudos em Petrologia e Geoquímica - CPGq

Prograde and retrograde magnesian skarns associated with the Caçapava do Sul Granitic Complex intrusion (central Dom Feliciano Belt, southern Brazil) host Cu–Fe (Mo–Au) mineralization. Vein and contact prograde skarns contain disseminated pyrite, pyrrhotite, molybdenite, and chalcopyrite formed from the interaction of mafic and felsic intrusions an...

Na estratigrafia do Rio Grande do Sul as formações Santa Tecla e Tupanciretã foram consideradas preliminarmente pós Gondwânicas a partir de datações relativas. São interpretações originadas a partir de um limitado conjunto de dados, de caráter preliminar ou especulativo. Este estudo tem o objetivo de revisar e analisar estes trabalhos dispersos e a...

The development of porosity during rock weathering is a key process controlling nutrients release, water holding capacity available for plants and water flow. Here we used X-ray Computed Tomography (XRCT) and ¹⁴C PolyMethylMethAcrylate (PMMA) autoradiography to show how cracks are created and enlarged during initial weathering stages (saprock and s...

The oblique collision of the Congo, Kalahari, and Rio de la Plata cratons resulted in the formation of the Dom Feliciano Belt that evolved from rifting, drifting, and amalgamation between ca. 1.0 and 0.5 Ga. The post-collisional stage of the orogenic event (ca. 600 – 530 Ma) is marked by lithospheric scale shear-zones, voluminous magmatism, and vol...

Weathering transforms fresh un-weathered rock into saprolite and soils, porous materials that may hold available water for plants and nutrients. The conjoint characterization of mineral weathering and development of porosity is helpful in understanding rock weathering and the development of soil. The objective of this study was to investigate miner...

A interpretação visual de pares estereoscópicos obtidos a partir da imagem Google Earth Pro, em diferentes escalas, propiciou o reconhecimento de diversas morfoestruturas anelares na Bacia do Paraná, no Rio Grande do Sul cuja geometria é essencial para a locação de sítios favoráveis à captação de água subterrânea. O estudo efetuado resultou no reco...

Dust particle studies in ice cores from the tropical Andes provide important information about climate dynamics. We investigated dust concentrations from a 22.7 m ice-core recovered from the Quelccaya Ice Cap (QIC) in 2018, representing 14 years of snow accumulation. The dust seasonality signal was still preserved with homogenization of the record...

The object of this study is magnesian clay minerals present in carbonate rocks of the post-rift phase of the pre-salt in the Santos Basin. These rocks developed in an Aptian-age alkaline lacus-trine environment. This study summarizes the formation of clay minerals associated with different lithotypes in a range of 19 m and a depth of more than 5100...

Dust particle studies in ice cores from the tropical Andes provide important information about climate dynamics. We investigated dust concentrations from a 22.7 m ice-core recovered from the Quelccaya Ice Cap (QIC) in 2018, representing 12 years of snow accumulation. The dust seasonality signal was still preserved with some homogenization of the re...

This paper proposes the generation and closure of a proto-ocean and formation of an island arc in the Neoproterozoic Passo Feio Metamorphic Complex (PFMC), Caçapava do Sul region, southern Brazil. The PFMC, São Gabriel Terrane, consists of a Neoproterozoic supracrustal metavolcano-sedimentary sequence intruded by the Caçapava Granite. The study use...

Fluorite-mica-feldspar hydrothermal veins and stockworks host PbZnCu sulphides in the São Gabriel Terrane, Southern Brazil. The veins fill second- and third-order structures in Neoproterozoic calcitic marbles on the Cambaizinho Complex. Veins are mostly symmetrically zoned showing, from borders to the centre, fluorite and sericite, muscovite, adula...

Carbonatites were recently discovered in Southern Brazil, which increased the interest to evaluate the economic potential of these uncommon rocks, especially the Três Estradas Carbonatite. Carbonates are the dominant minerals of fresh rock followed by apatite, but the weathering process makes apatite abundant. We focused on apatite from the carbona...

The Ibaré Lineament is a shear zone that sections the Western portion of Sul-riograndense Shield, affecting the orthogneissic rocks of Santa Maria Chico Granulitic Complex, acting as a conduct for hydrothermal fluids. The studied hydrothermal mineralogy reflects a propylitic alteration paragenesis that is composed of Fe-clinochlore, epidote, albite...

Andean tropical glaciers have shown a clear shrinkage throughout the last few decades. However, it is unclear how this general retreat is associated with variations in rainfall patterns in the Amazon basin. To investigate this question, we compared the annual net accumulation variations in the Bolivian Cordillera Real (Andes), which is derived from...

A morfologia de canais é resultado do ambiente em que se encontram, assim como de todas variáveis físicas atuantes. Se a desembocadura está situada em zonas costeiras, a tendência à instabilidade é amplificada pelo próprio meio. Neste artigo são apresentados os resultados do estudo morfodinâmico do canal de comunicação entre a Lagoa do Peixe e o Oc...

This work investigated the origin and evolution of chloritites and chlorite bearing rocks and Cu-Fe sulfides, associated with sill and apophysis of the Caçapava Granite, which intrude in the dolomitic marbles of the Passo Feio formation, Terrane São Gabriel of the Sul-Riograndense Shield. The interaction of the granite fluids with the marbles gener...

RESUMO: Associações de rochas máficas e ultramáficas possuem grande potencial para mineralização, especialmente de Cu-Pb-Zn, Ni-Cr e EGP (elementos do grupo da platina), respectivamente. No estado de Sergipe corpos máficos-ultramáficos foram identificados pela CPRM (Serviço Geológico do Brasil) em 2001 na Faixa de Dobramentos Sergipana (FDS). No en...

Magmatismo associado com o estágio pré-evaporítico da Bacia de Campos foi estudado a partir de testemunhos de quatro furos de sondagens. Os dados levantados são importantes no contexto da evolução tectônica e estratigráfica da bacia. O objetivo deste trabalho foi a caracterização dessas rochas a partir da petrografia, litoquímica, química mineral e...

The integrated evaluation of soil geochemistry, aerogammaspectrometry (eTh), geological and structural mapping associated with the description of boreholes and outcrops in the Caçapava do Sul region, southernmost Brazil, led to the discovery of two carbonatite bodies. They are located near the eastern and southeastern border of Caçapava do Sul Gran...

Este artigo tem como objetivo identificar e apresentar argumentos mineralógicos e químicos que demonstrem a existência de níveis de bentonitas inseridos na Formação Irati, em afloramentos a leste da cidade de Aceguá, sul do Rio Grande do Sul. Tratam-se de níveis com pequena espessura (em média 4 cm) e grande extensão lateral, constituídos de argili...

The inlets morphology is a result of the environment in which they are, as well as all active physical variables. If the mouth is situated in coastal areas, the trend towards instability is amplified by the environment itself. This paper presents the results of a morphodynamic study of the communication inlet between the Lagoa do Peixe and the Atla...

As rochas ultramáficas serpentinizadas do Complexo Passo Feio afloram a noroeste do Granito Caçapava, no Escudo Sul Rio-grandense (ESRg), Rio Grande do Sul (RS). O Complexo Passo Feio é constituído por rochas metassedimentares com intercalações de anfibolitos, xistos magnesianos e serpentinitos, constituindo-se de uma seqüência meta vulcano sedimen...

Carbonatitos são rochas exóticas, volumetricamente insignificantes do ponto de vista de distribuição mundial, portadora de metais raros e com origem a partir de magmas primários. Ocorrem em diferentes idades, desde o arqueano até o recente, com maior incidência no Cretáceo. Podem ser portadores de depósitos estratégicos de Elementos Terras Raras, f...

Bentonite mining, blending and first stages of raw processing are usually planned based on physical properties and smectite content of the bulk material, in order to appoint a proper market destination. What if there was a structural feature from smectitic phases that could stablish feasibility for advanced and high added-value applications, right...

This work investigates the metamorphic processes in ultramafic rocks of the Passo Feio Complex (PFC) that is a sequence of metapelite, amphibolite, metavolcanic/metavolcanoclastic rocks, marble, calc-silicate rocks, quartzite, magnesium schist and serpentinites. It is part of the São Gabriel Terrane, a juvenile arc formed during the early stages of...

This work correlates surface and ground water composition to the substrata, and traces how water chemistry evolves at Brazil’s largest coal mine, the Candiota Mine. The water is dominated by SO4, Fe, Ca, and Mg. A pH range of 2.7–3 in the pit lakes is attributed through chemical models to concomitant pyrite oxidation and carbonate dissolution along...

(Controles mineralógicos e geoquímicos do níquel em rochas ultramáficas no Escudo Sul-Riograndense) (Mineralogical and geochemical controls of nickel in the ultramafic rocks of Sul-Riograndense Shield) This work investigates the processes controlling the mobility and concentration of nickel in serpentinized ultramafic rocks of the Sul-Riograndens...

In a subduction zone, water-rich pelagic sediments overlying the subducting oceanic plate are accumulated, forming an accretionary wedge. A portion of these sediments, primarily smectites, can subduct and lose the water present in their pores, but the mechanism of the clay structural transformation and its composition are not well-defined. Smectite...

RESUMO O presente estudo apresenta resultados da análise morfométrica do setor norte da Baía do Almirantado, localizada na ilha Rei George, arquipélago das Shetlands do Sul, Antártica, com a utilização do Sistema de Informações Geográficas (SIG). Fotografias aéreas verticais foram processadas para a geração de um ortofotomosaico e de um Modelo Digi...

RESUMO: The coexistence of calcite and dolomite in metamorphic rocks allows the application of a geothermometric method where the range of immiscibility between both minerals in the system CaCO 3-CaMg (CO 3) 2 is considered. Thus, the amount of MgCO 3 in calcite coexisting with dolomite is used here to estimate metamorphic equilibrium temperatures....

RESUMO: Este trabalho tem como objetivo investigar os processos controladores da mobilidade e concentração de níquel (Ni) em rochas ultramáficas serpentinizadas no Escudo Sul-Riograndense (ESrg), Rio Grande do Sul (RS), Brasil. A composição primária das rochas ultramáficas hospedeiras de Ni constitui um parâmetro relevante, mas os processos secundá...

RESUMO: Diversas ocorrências de mármores do Escudo Sul-Rio-Grandense estão intrudidas por rochas granitóides e/ou vulcânicas do Ciclo Brasiliano. A interação dos fluidos magmáticos com as rochas carbonáticas do escudo gera escarnitos com diferentes padrões e zonações mineralógicas, frequentemente associados com sulfetos de Cu, Fe (Au) e/ou Pb-Zn. I...

Fluvial and estuarine sandstones of the Aptian Mucuri Member of the Mariricu Formation are the main reservoir rocks in the onshore portion of the Espírito Santo Basin, Brazilian eastern margin. These sandstones are contemporaneous with the major lacustrine pre-salt reservoir rocks which are currently the target of exploration offshore. The sandston...

Durante cerca de 40 anos o curso de geologia da UFRGS formou profissionais com base em um currículo cujo trabalho de conclusão dava-se por meio de um mapeamento geológico básico. A partir dos anos de 1990, deu-se início a uma profunda mudança curricular que culminou, no início dos anos 2000, com a implantação de nova modalidade de trabalho de concl...

234 Este trabalho investiga os processos controladores da mobilidade e concentração de níquel (Ni) em rochas ultramá¿ cas serpentinizadas no Escudo Sul-Riograndense (ESrg), Rio Grande do Sul (RS), Brasil. A composição primária das rochas ultramá¿ cas hospedeiras de Ni constitui um parâmetro relevante, mas os processos secundários são os controlador...

Resumo-Esta nota explicativa se refere ao mapa geológico de parte da Folha Arroio América (SH.22-Y-A-IV-1 / MI 2995/1) e tem por base os resultados obtidos durante o Projeto Arroio América, executado em 2003 por professores e alunos do Curso de Geologia da Universidade Federal do Rio Grande do Sul. Diversas unidades litoestratigráficas foram reconh...

Most readers would agree on the fact that layer charge is the most determinant property from Smectites phases present in Bentonite deposits, to comprehend the overall interaction behavior of this materials for scientific and Industrial uses. Nevertheless, there is yet a lot to be discovered regarding diagenetic implications on magnitude and nature,...

Os mármores calcíticos de Vila Nova do Sul, pertencentes ao complexo Cambaizinho no Bloco São Gabriel apresentam uma variedade de domínios mineralógicos derivados de reações formando paragêneses específicas devido à interação de fluidos de origem magmática com a rocha encaixante carbonática. Duas situações bem distintas ocorrem na área: uma paragên...

1. Thamy L. de Souza, aluna de Pós-Graduação em Geociências-UFRGS: thamy.lara@yahoo.com.br; 2. Marcus V. D. Remus, Prof. Dr. Do Instituto de Geociências-UFRGS: marcus.remus@ufrgs.br; 3. Norberto Dani, Prof. Dr. Do Instituto de Geociências-UFRGS: Norberto.dani@ufrgs.br; 4. Milton L. L. Formoso, Prof. Dr. Do Instituto de Geociências-UFRGS: milton.for...

As rochas carbonáticas do embasamento do Rio Grande do Sul estão encaixadas em sequências vulcano-sedimentares ou gnaisses quartzo-feldspáticos de idade Pre-Cambriana. Invariavelmente as diferentes ocorrências de sequencias carbonáticas do Escudo Sul Rio-grandense estão afetadas pelo metamorfismo orogênico desde o grau muito-baixo até o grau alto,...

This explanatory note refers to the geological map of part of the Arroio América Sheet (SH.22-Y-A-IV-1 / MI 2995/1) and is based on the results obtained during the Arroio América Project, carried out in 2003 by professors and undergraduate students of the Geology Course, Federal University of Rio Grande do Sul. Seve ral lithostratigraphic units wer...

The Keller Peninsula (KP), on the King George Island, shelters the Brazilian Comandante Ferraz Station (EACF) and it has been the site from several international research projects. However, this area has not yet been mapped in detail, except for the area around the EACF, which is mapped at 1:500. Aiming to overcome the lack of a detailed and accura...

This study uses a Geographical Information System (GIS) for terrain analysis of the Keller Peninsula (KP), King George Island (KGI), Antarctica, to describe its morphological characteristics. We processed a vertical metric aerial photography and a Digital Terrain Model (DTM) in a Digital Photogrammetric Station to generate an orthophoto and then to...

Planialtimetric maps with good level of accuracy and at detailed scales may be used to improve geographic location information of the place names in the Composite Gazetteer of Antarctica (CGA), developed by the Scientific Committee on Antarctic Research (SCAR). In this study, a Geographical Information System (GIS) was used to obtain information on...

New zircon ages of claystone beds in bentonites and tonsteins from SW of Rio Grande do Sul and their probable counterpart (the Late Palaeozoic Choiyoi Volcanic Belt, W-NW of Argentine) allow to investigate the possibility of a detailed geochemical and provenance correlation. The claystone are considered the result of Permian tephras totally transfo...

2-IGEO-UFRGS – norberto.dani@ufrgs.br; 3-IGEO-UFRGS – carolinagazzoni@gmail.com; 4-IGEO-UFRGS – gui.ois@gmail.com; 5-IGEO-UFRGS – sdosreis.rafael@gmail.com Resumo Este trabalho mostra que os minérios de Cu-Au-Fe hospedados em mármores dolomíticos da região de Caçapava do Sul são depósitos de substituição tardios de baixa temperatura, relacionados a...

This study consists in the morphometric analysis of Keller Peninsula (KP), South Shetland Archipelago, Antarctica, using Geographical Information System (GIS) techniques. We processed a vertical metric aerial photography and a Digital Terrain Model (DTM) used in the compilation of the KP topographic map at a scale of 1:5,000, in a Digital Photogram...

The Keller Peninsula (KP), on the King George Island (South Shetlands Archipelago), shelters the Brazilian Comandante Ferraz Station (EACF) and it has been the site from several national and international research projects. However, this area has not yet been mapped in detail, except for the area around the EACF, which is mapped at 1:500. This work...

The bentonite deposit found in the region of Bañdo de Medina, 18 km southwest of the locality of Melo, in Uruguay, is the first one of commercial potential in that region. The aim of this work is to present mineralogy, chemical composition, types of contaminants and factors that control the deposits and technological properties of the bentonite. A...

O depósito de bentonita da região de Bañado de Medina, situado 18 km a sudoeste da localidade de Melo, no Uruguai, constitui a primeira ocorrência na região com potencial para exploração comercial. O objetivo deste trabalho é apresentar dados referentes à mineralogia, composição química, tipos de contaminantes e fatores de controle dos depósitos, b...

The Keller Peninsula (KP), on the King George Island, shelters the Brazilian Comandante Ferraz Station (EACF) and it has been the site from several international research projects. However, this area has not yet been mapped in detail, except for the area around the EACF, which is mapped at 1:500. Aiming to overcome the lack of a detailed and accura...

Methods used for compilation of the slope map are fully described in: https://www.researchgate.net/publication/235964117_Terrain_analysis_of_the_Keller_Peninsula_King_George_Island_Antarctica_by_gis_techniques

The Keller Peninsula (KP), on the King George Island, shelters the Brazilian Comandante Ferraz Station (EACF) and it has been the site from several international research projects. However, this area has not yet been mapped in detail, except for the area around the EACF, which is mapped at 1:500. Aiming to overcome the lack of a detailed and accura...

This study uses a Geographical Information System (GIS) for terrain analysis of the Keller Peninsula (KP), King George Island (KGI), Antarctica, to describe its morphological characteristics. We processed a vertical metric aerial photography and a Digital Terrain Model (DTM) in a Digital Photogrammetric Station to generate an orthophoto and then to...

The Keller Peninsula (KP), on the King George Island, shelters the Brazilian Comandante Ferraz Station (EACF) and it has been the site from several international research projects. However, this area has not yet been mapped in detail, except for the area around the EACF, which is mapped at 1:500. Aiming to overcome the lack of a detailed and accura...

This study uses a Geographical Information System (GIS) for terrain analysis of the Keller Peninsula (KP), King George Island (KGI), Antarctica, to describe its morphological characteristics. We processed a vertical metric aerial photography and a Digital Terrain Model (DTM) in a Digital Photogrammetric Station to generate an orthophoto and then to...