Fractional Crystallization
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. Evaluation of the contributions of possible sources to the leucosome of the diatexite of Socorro-Guaxupé Nappe, in the Alfenas Region, MG, Brazil
Abstract The Socorro-Guaxupé Nappe crops out in southern Minas Gerais and it has an intermediate unit called Metaxite Unit, dominated by diatexites at its base, with large volumes of leucosome and schollen of stromatic garnet-biotite metatexite. Leucosome within the schollen crystallized via fractional crystallization and is dominated by plagioclase and qua
Braz. J. Geol.. Publicado em: 08/04/2019
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2. Geochemistry of basaltic flows from a basalt ring structure of the Serra Geral formation at Água Vermelha dam, Triângulo Mineiro, Brazil: implications for the magmatic evolution of the Paraná-Etendeka Province
ABSTRACT: The Serra Geral Formation belongs to the Paraná-Etendeka Magmatic Province (PEMP) and its geochemical and petrographic characteristics are not homogeneous. Many studies segment this group into six basaltic and two rhyolitic magma-types. It is believed that its extrusion occurred through crustal fissures in the Cretaceous, but some authors describe
Braz. J. Geol.. Publicado em: 2018-06
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3. Cretaceous carbonatites of the southeastern Brazilian Platform: a review
ABSTRACT: This paper reviews general aspects of alkaline-carbonatitic rocks of Brazilian, Paraguayan and Bolivian terrains. Although 30 such occurrences are known in literature, only the major ones have been thoroughly investigated. The carbonatites are of Cretaceous age, with two well-defined Lower Cretaceous and Upper Cretaceous generation episodes. A clea
Braz. J. Geol.. Publicado em: 2018-06
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4. Geology, geochemistry and petrology of basalts from Paraná Continental Magmatic Province in the Araguari, Uberlândia, Uberaba and Sacramento regions, Minas Gerais state, Brazil
Abstract: This study covers the region between the cities of Sacramento and Araguari/Uberlândia (Minas Gerais State, Brazil), where basalt flows from the Paraná Continental Magmatic Province outcrop. The investigated rocks present tholeiitic signature, with high titanium content, and are classified as Pitanga magma-type. The preserved basalt thickness is b
Braz. J. Geol.. Publicado em: 22/02/2018
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5. Geochemical behaviour of trace elements during fractional crystallization and crustal assimilation of the felsic alkaline magmas of the state of Rio de Janeiro, Brazil
RESUMO Este trabalho apresenta os comportamentos geoquímicos de elementos traços das rochas alcalinas félsicas do Estado do Rio de Janeiro, Brasil, com atenção especial da cristalização fracionada e assimilação da crosta continental. O fracionamento de leucita e de feldspato alcalino potássico aumenta Rb/K e reduz K2O/(K2O+Na2O). Os magmas primitiv
An. Acad. Bras. Ciênc.. Publicado em: 27/11/2015
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6. On dynamic self-organization: examples from magmatic and other geochemical systems
Standard Liesegang banding is the display of parallel bands of precipitate formed periodically when co-precipitate ions interdiffuse in a gel medium. The most striking resemblance with Liesegang patterns in Nature lies in the diverse scenery of banded textural features commonly observed in some geological materials, such as geodes, agates, malachites, as wel
Lat. Am. j. solids struct.. Publicado em: 2013-01
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7. CALFRAC: Programa que quantifica o processo de cristalização fracionada e sua aplicação ao estudo de soleiras da Bacia do Paraná (Estado do Paraná) / CALFRAC: Program to quantify fractional crystallization processes and your application in the study Paraná Basin sills (Paraná).
CALFRAC is a computer program written in C++ programming language developed to quantify fractional crystallization processes in igneous systems. Major, minor and trace element concentrations are used as input for calculations. The new algorithm enhances and makes the program more efficient than those published in the literature. Besides it is capable to auto
Publicado em: 2010
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8. Caracterização petrográfica e geoquímica da parte leste do Granito Europa, Distrito Mineiro de Pitinga, AM
The important mineral deposits of the Pitinga Mine, in the Amazonian region are related to A-type granites intruded in the Iricoumé Group. The Europa granite is one of these A-type rocks, intruded in the Iricoumé Group, which is represented by subaerial vulcanoclastic rocks (crystal-rich ignimbrites, thin massive tuffs and siltic tufaceous arenites) and mi
Publicado em: 2010
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9. Petrogêneses do complexo vulcânico Yate (42, 30ºS), Andes do Sul, Chile / Petrogenesis of the Yate Volcanic Complex (42, 30ºS), Andes Southern, Chile
The Yate Volcanic Complex (CVY) is located in the Southern Volcanic Zone of the Chilean Andes, at 42°30S, comprising the Yate, Gualaihué and Hornopirén volcanoes. The Yate volcano is a major compound type in which effusive activity occurred since Upper Pleistocene (c. 122 ka) until Holocene. Hornopirén and Gualaihué are minor, and represent strombilian-
Publicado em: 2009
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10. 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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11. Petrologia da sucessão magmática do Arquipélago de Abrolhos
The Magmatic Succession of Abrolhoss Archipelago is composed by four units: Olivine-Plagioclase Basalt (b1), Pyroxene-Plagioclase-Olivine Basalt (b2), Pyroxene-Plagioclase Basalt (b3) and Cumulado (b4). The units are not stratigraphically correlated. They are stacked from the basis to the top in units: b1, b2, b3 and b4. The units of the magmatic succession
Publicado em: 2008
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12. A unidade Maria Preta : geologia, geoquimica e petrogenese de rochas vulcanicas e sub-vulcanicas intermediarais a felsicas no "Greenstone Belt" do rio Itapicuru, Bahia / The Maria Preta unit : geology, geochemistry and petrogenesis of volcanic and sub-volcanic intermediate to felsic rocks in the Rio Itapicuru greenstone belt, Bahia
New geochemical data on andesites and dacites of the Maria Preta Unit, Rio Itapicuru Greenstone Belt, revealed two distinct geochemical groups: one of adakitic affinity and another of typical calc-alkaline. The adakitic suite, localized west in the unit, is characterized by high values of Sr/Y and Ti/YN >1. It shows enrichment in LFSE (Low Field Strength Ele
Publicado em: 2008