Results 101 to 110 of about 7,546 (232)

Exemplos de efeito tétrade nos lantanídeos em sistemas naturais

open access: yesGeologia USP. Série Científica, 2014
Padrões irregulares de elementos terras raras causados pelo denominado efeito tétrade são revisados e discutidos neste trabalho, incluindo sua conceituação e subdivisão em tipos M e W, quantificação e mecanismos que os geram em sistemas magmáticos ...
Lauro Valentim Stoll Nardi   +2 more
doaj  

Ordovician and Silurian igneous rocks and orthogeneisses in the Catalonian Coastel Ranges [PDF]

open access: yes, 1990
These rocks exhibit calc-alkaline affinities and may have originated by partial melting of the crust in a post-collision, anorogenic setting. Orthogneisses derived from biotite-bearing leucogranites occur within aprobably cambrian heterogeneous series ...
Gil Ibarguchi, José Ignacio   +2 more
core   +1 more source

Sienogranitos leucocráticos do Domínio Macururé, Sistema Orogênico Sergipano, Nordeste do Brasil: Stock Glória Sul

open access: yesBrazilian Journal of Geology
RESUMO: O Stock Glória Sul (SGS) (41 km2) é arredondado e intrusivo na parte central do Domínio Macururé, no Sistema Orogênico Sergipano (SOS). Internamente o Stock é formado por vários tipos de sienogranitos leucocráticos (biotita sienogranito ...
Joane Almeida da Conceição   +2 more
doaj   +1 more source

Automated petrography analysis by QEMSCAN® of a garnet-staurolite schist of the San Lorenzo Formation, Sierra Nevada de Santa Marta massif

open access: yesRevista Mexicana de Ciencias Geológicas, 2020
El análisis petrográfico automatizado integra hardware de microscopía electrónica de barrido y espectroscopía de rayos X con software experto para generar mapas de composición de rocas a escala de micras.
Carlos Alberto Ríos-Reyes   +2 more
doaj   +1 more source

Experimental techniques for determination of the role of diffusion and convection in crystal growth from solution [PDF]

open access: yes
Various studies of the concentration of the solution around a growing crystal using interferometric techniques are reviewed. A holographic interferometric technique used in laboratory experiments shows that a simple description of the solution based on ...
Zefiro, L.
core   +1 more source

Estudi petrològic i geoquímic del vulcanisme recent de la Garrotxa [PDF]

open access: yes, 2009
Màster en GeologiaLa zona volcànica de la Garrotxa forma, juntament amb les zones volcàniques de la Selva i l'Empordà, la província volcànica alcalina d'intraplaca del NE de Catalunya. En el cas de la zona olotina, tot i ser coneguda des de fa més de dos
Gisbert Pinto, Guillem
core  

Organic-rich shales from internal Betic basins (SE Spain): potential source rocks analogs for the pre-Messinian Salt play in the Western Mediterranean

open access: yesGeologica Acta, 2016
Southeastern Spain has a large number of Late Neogene basins with substantial evaporitic deposits that developed under an overall NNW-SSE compressional regime related to the African-European tectonic plates collision.
A. PERMANYER   +3 more
doaj  

Impact vesiculation – a new trigger for volcanic bubble growth and degassing [PDF]

open access: yes, 2007
We highlight a potentially important trigger for bubble growth and degassing in volcanic bombs. We have successfully triggered bubble growth in previously unvesiculated samples of silicate melt during experiments to simulate volcanic bomb impact, by ...
Dingwell, D. B.   +3 more
core   +1 more source

Colocação, metamorfismo e natureza dos anfibolitos de Água Azul do Norte, Província Carajás

open access: yesGeologia USP. Série Científica, 2018
Os corpos metamáficos de Água Azul do Norte, porção centro-sul do Domínio Carajás, são intrusivos em uma crosta TTG e correspondem a duas variedades: (i) actinolita anfibolito, que ocorre como um corpo alongado de orientação geral N-S e inflexão para NE,
Diwhemerson Barbosa de Souza   +4 more
doaj   +1 more source

Tesis doctoral: Estudio Gravimétrico del Pirineo Oriental [PDF]

open access: yes, 1994
This dissertation is primarily a gravimetric study of Eastern Pyrenees based on gravity prospecting techniques combined with seismic reflection profiles, magnetic survey, and the existing bore-holes. The two main objectives of the study are interpret the
Rivero Marginedas, Lluís
core   +1 more source

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