HR: 0800h
AN: T51A-0432    [Abstracts]
TI: Geometric and Fractal Characteristics of Veins in San Joaquin, Queretaro, Mexico
AU: * Yussim, S
EM: yussim@servidor.unam.mx
AF: Geography Department, Philosophy and Letters Faculty, UNAM, Circuito Escolar s/n Ciudad Universitaria. Av. Universidad 3000, Col. Copilco., Mexico City, DF 04510 Mexico
AU: Flores-Estrella, H C
EM: hcflorese@yahoo.com.mx
AF: Posgrado en Ciencias de la Tierra, Instituto de Geofisica, UNAM, Circuito Escolar s/n Ciudad Universitaria. Av. Universidad 3000, Col. Copilco., Mexico City, DF 04510 Mexico
AB: This work was made in the most eastern part of the Fold and Fault Mexican Belt of the Sierra Madre Oriental, where a sea Mesozoic sequence is exposed and formed by three lithostratigraphic units with different mechanical characteristics: the upper and lower mechanically incompetents, and the middle one mechanically competent. From the geometrical point of view, four vein systems were identified: the oldest one parallel to the stratification; two other more recent and contemporaneous with general orientations N75øE, 70øSE and N25øE, 70øSE, which are symmetrical to the youngest one with orientation N50øE, 80øSE. All the system orientations are compatibles with the tectonic transport of the area. In the other hand, Fractal Geometry application allows describing vein characteristics that conventional techniques does not: as the filled space measurement and the power laws that rule veins. The fractal analysis consisted on various stages: the first one was made with developed software, which estimates the fractal dimension of an image basing on box-counting method. All the vein systems images were studied by site, and it was found that the fractal dimension varied from 1.2 to 1.8, and the largest values were associated with the most competent lithology and not with the most competent unit. With the analysis for each vein system the fractal dimension varied from 1.1 to 1.82, and it was concluded that the values tend to decrease as the systems are younger, and the intermediate systems have the larger variation because they were affected by the latest vein system.
DE: 8005 Folds and folding
DE: 8010 Fractures and faults
DE: 8020 Mechanics
DE: 8094 Instruments and techniques
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting