Contributos da detec????o remota para a evid??ncia e localiza????o de pegmatito...

• Author(s): Pereira, B. ; Azevedo, J. ; Oliveira, J. ; Dias, Patr??cia Sofia Alves ; Gomes, C. Leal ; Carvalho, J. ; Marques, A.
• Date: 2012
• Persistent ID: http://hdl.handle.net/1822/30031
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Pegmatitos; Detec????o remota; Alinhamentos curvil??neos; Plumas de ???ballooning???; Invari??ncia escalar; Pegmatites; Remote sensing; Curvilinear alignments; Ballooning; Scalar invariance
• Document Type: Part of book or chapter of book
• Language: Portuguese
• Editor(s): Ferreira, M. Quinta; Barata, M. T.; Lopes, F. C.; Andrade, A. I.; Henriques, M. H.; Pena dos Reis, R.; Alves, E. Ivo

Description

"I Congresso Internacional de Geoci??ncias na CPLP" Em contexto de prospec????o de bolsadas pegmat??ticas hospedadas em granitos da regi??o de Ponte da Barca, procurou??????se, combinando t??cnicas de an??lise distanciada e levantamento de campo, detectar interfaces litol??gicas com as quais se pudesse relacionar a organiza????o espacial e estrutural dos pegmatitos a?? aflorantes. A evid??ncia de alinhamentos curvil??neos em imagens do Landsat, sobretudo bem marcados nas imagens que resultam da aplica????o de algoritmos de classifica????o Maxver, s??o compat??veis com a exist??ncia de fluidalidades planares ou plano??????lineares conc??ntricas, possivelmente herdadas de plumas de ???ballooning???, verificando??????se uma correla????o espacial entre a localiza????o dos pegmatitos e as suas periferias, que separam dom??nios diferenciados de ???clustering??? de fenocristais. Within the context of prospecting operations of pegmatite bodies hosted in granites in the Ponte da Barca region, we sought to detect lithologic interfaces from which the relationship between the spatial and structural organization of the outcropping pegmatite bodies could be established, by combining field work and remotely sensed data analysis. The evidence of curvilinear alignments in LANDSAT imagery, especially well???marked in the images obtained from the application of classification algorithms, are compatible with the existence of concentric planar or plan???linear fluidalities, possibly inherited from ballooning plumes. We thus verified a spatial correlation between the pegmatite outcrops and ballooning plumes peripheries, which separate different domains of phenocristaline clustering.