Volcanic Processes
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Genesis and Classification of Nitisols from Volcano-Sedimentary Lithology in Northeastern Brazil
ABSTRACT On the southern coast of Pernambuco State (PE), Brazil, lithotypes of the Cabo Basin (volcanic and sedimentary rocks), in association with the relief, allow the determination of the dynamics of the formation of Nitossolos Háplicos (Nitisols), including those with high levels of exchangeable aluminum. The objective of this study was to evaluate the
Rev. Bras. Ciênc. Solo. Publicado em: 14/02/2019
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2. Pedogenesis in an Archaeological Dark Earth – Mulatto Earth Catena over Volcanic Rocks in Western Amazonia, Brazil
ABSTRACT Archaeological Dark Earth (ADE) pedogenesis and pre-Columbian history are fundamental for understanding the biodiversity and pedodiversity of the Neotropical rainforest in the Amazon region. This study aimed to evaluate the morphological, physical, chemical, and mineralogical properties as well as NaOH-extractable organic matter [OM(NaOH)] in ADE an
Rev. Bras. Ciênc. Solo. Publicado em: 06/08/2018
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3. Paralavas in the Cretaceous Paraná volcanic province, Brazil - A genetic interpretation of the volcanic rocks containing phenocrysts and glass
ABSTRACT The occurrences of glassy rocks containing long and curved phenocrysts in the Paraná volcanic province, South America, are here interpreted as paralavas. The large number of thin (0.1-0.5 m) dikes and sills of glassy volcanic rocks with hopper, hollow or curved, large crystals of clinopyroxene (up to 10 cm), plagioclase (up to 1 cm), magnetite and
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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4. Geocronologia da região de Gondola-Nhamatanda (Centro de Moçambique) / não informado
The region of Gondola-Nhamatanda is located at the border between the provinces of Manica and Sofala, central part of Moçambique. It is geologically inserted in the Bárue complex and the Phanerozoic cover. The Bárue complex is composed of the Macossa and Chimoio supracrustal groups intruded by plutonic rocks of various compositions, whereas the Phanerozoi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/01/2012
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5. Paleoproterozoic (~1.88Ga) felsic volcanism of the Iricoumé Group in the Pitinga Mining District area, Amazonian Craton, Brazil: insights in ancient volcanic processes from field and petrologic data
O Grupo Iricoumé corresponde ao mais expressivo vulcanismo Paleoproterozóico do Escudo das Guianas, craton Amazônico. As rochas vulcânicas são coexistentes com os granitóides Mapuera, e pertencem ao magmatismo Uatumã. Possuem idades U-Pb em torno 1888 Ma, e assinaturas geoquímicas de magmas tipo-A. As vulcânicas do Iricoumé consistem de traquitos a
Anais da Academia Brasileira de Ciências. Publicado em: 2011-09
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6. Os Depósitos de Cu-Au-Mo do tipo pórfiro de Bajo de La Alumbrera e Água Rica, Argentina : considerações genéticas sobre formação e fonte de minério
The world-class deposits of Bajo de la Alumbrera and Agua Rica in NW Argentina, are of the Cu-Au-Mo porphyry type (although Agua Rica has some epithermal characteristics). Both deposits are closely related to the activities and formation processes of the Miocene Farallón Negro Volcanic Complex. They are also controlled by the Tucuman Transfer Zone, which is
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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7. Depósitos de fluxo piroclástico primários: caracterização e estudo de um caso no vulcanismo ácido neoproterozóico do escudo sul-rio-grandense
Volcanic deposits can be included in two main groups: coherent and volcaniclastic. The former results from volcanic and sub-volcanic (syn-volcanic intrusions) effusive events, excluding autoclastic portions, and the second group, which is related to deposits constituted by volcanic fragments, encompassing primary deposits (pyroclastic) generated from fragmen
Publicado em: 2010
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8. Structural constraints on Paraná basalt volcanism and their implications on agate geode mineralization (Salto do Jacuí, RS, Brazil)
The Paraná-Etendeka Continental Flood Basalt province hosts world-class agate and amethyst geode deposits in Rio Grande do Sul (Brazil; Serra Geral Fm.). Salto do Jacuí Mining District (Rio Grande do Sul, Brasil) has different types of agate geode hosted in vesicular basalt. A series of structural features has recently been investigated in the Salto do Jac
Publicado em: 2010
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9. Razões isotópicas 87Rb/86Sr, 87Sr/86Sr e 143Nd/144Nd como traçadores de proveniência de rochas sedimentares siliclásticas: exemplos no Grupo Camaquã(Paleozóico interior; RS, Brasil)
The Rb-Sr and Sm-Nd isotopic systems are ideal in constraining the provenance of fine-grained clastic rocks. This is particularly true for continental, fluvio-lacustrine, sedimentary units deposited under semi-arid climate conditions, where mechanical desintegration of source rocks dominates the weathering processes. Three sets of red-colored, continental si
Publicado em: 2010
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10. Evolução magmática, alteração hidrotermal e gênese da mineralização de ouro e cobre do Palito, Província Aurífera do Tapajós (PA) / Magmatic evolution, hydrothermal alteration and geneseis of gold-copper mineralization at Palito, Tapajós Gold Province (PA)
The Palito porphyry type copper-gold deposit is located in the central region of the Amazonian craton, in the Tapajós Gold Province (TGP), in an area that is dominated by intermediate to felsic granitic and volcanic rocks of late Paleoproterozoic age. Three lithotypes make up this deposit. The Palito Granite, with porphyritic features, is the host rock for
Publicado em: 2010
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11. Estratigrafia e petrogênese das sequências vulcânicas paleoproterozóicas na região de São Félix do Xingu (PA), Província Mineral de Carajás / Stratigraphy and petrogenesis of the paleoproterozoic volcanic sequences in the São Félix do Xingu (PA) region, Carajás Mineral Province
Near the São Félix do Xingu city, centersouth portion of the Pará state, in the context of the Carajás Mineral Province, occur extensive Paleoproterozoic volcanoplutonism (1.88 1.87 Ga) exceptionally well-preserved and grouped in the Sobreiro and Santa Rosa formations. These suites are generically correlated to Uatumã Supergroup volcanoplutonism, a magm
Publicado em: 2009
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12. Características epigenéticas do depósito de cu-au chapada, arco magmático de goiás
The Cu-Au Chapada deposit is located from 8km of Alto Horizonte-GO. The geologic picture is dominated by metavulcanic sedimentary sequences that integrate the Neoproterozoic Magmatic Arc of Mara Rosa, located in the central portion of the Tocantins Province. The framework of the deposit is represented by an antiform whose core is composed by association of t
Publicado em: 2009