Two- and three-dimensional shape fabric analysis by the intercept method in grey levels

Autor(es)

Launeau, Patrick ^[1] ; Archanjo, Carlos J. ^[2] ; Picard, David ^[3] ; Arbaret, Laurent ^[3] ; Robin, Pierre-Yves ^[4]

Afiliação do(s) autor(es)

^[1] Univ Nantes, Lab Planetol & Geodynam Nantes, UMR 6112, CNRS, F-44322 Nantes - France

^[2] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[3] Univ Orleans, Inst Sci Terre Orleans, UMR 6113, CNRS, F-45071 Orleans - France

^[4] Univ Toronto, Dept Geol, Toronto, ON M5S 3B1 - Canada

• Tipo de documento: Artigo Científico
• Fonte: TECTONOPHYSICS; v. 492, n. 1-4, p. 230-239, SEP 20 2010.
• Citações Web of Science: 33

Resumo

The count intercept is a robust method for the numerical analysis of fabrics Launeau and Robin (1996). It counts the number of intersections between a set of parallel scan lines and a mineral phase, which must be identified on a digital image. However, the method is only sensitive to boundaries and therefore supposes the user has some knowledge about their significance. The aim of this paper is to show that a proper grey level detection of boundaries along scan lines is sufficient to calculate the two-dimensional anisotropy of grain or crystal distributions without any particular image processing. Populations of grains and crystals usually display elliptical anisotropies in rocks. When confirmed by the intercept analysis, a combination of a minimum of 3 mean length intercept roses, taken on 3 more or less perpendicular sections, allows the calculation of 3-dimensional ellipsoids and the determination of their standard deviation with direction and intensity in 3 dimensions as well. The feasibility of this quick method is attested by numerous examples on theoretical objects deformed by active and passive deformation, on BSE images of synthetic magma flow, on drawing or direct analysis of thin section pictures of sandstones and on digital images of granites directly taken and measured in the field. (C) 2010 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 04/13121-1 - Patrick Launeau | Université de Nantes - França
• Beneficiário: Carlos José Archanjo
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 01/14154-2 - Petrotrama de diamictitos e deformacao sin-sedimentar em depositos glaciais.
• Beneficiário: Carlos José Archanjo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 01/10626-7 - Análise de relação entre petrotrama e a anisotropia de suscetibilidade magnética
• Beneficiário: Carlos José Archanjo
• Modalidade de apoio: Bolsas no Exterior - Pesquisa