| Koehn, D., Bons, P.D., Hilgers, C. & Passchier, C.W. 2001. Animations of progressive fibrous vein and fringe formation. In: Ailleres, L. and Rawling, T. 2001. Animations in Geology. Journal of the Virtual Explorer, 4. |
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Animations
of progressive fibrous vein and fringe formation
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ConclusionsVaried and often complex textures in veins and strain fringes can be realistically modelled (in 2 dimensions) with the programs "Vein Growth" and "Fringe Growth", respectively. The tracking capability of fibres depends mainly on the roughness of the growth surface, as crystal boundaries tend to lock onto asperities of the wall-rock or object surface (Urai et al., 1991). Displacement-controlled fibres thus track the relative movement between vein/fringe and wall-rock/object. This movement is not necessarily parallel to the extensional ISA and different displacement-controlled fibres may grow in different directions at the same time. Care should therefore be taken in the structural analysis of fibres, especially those in strain fringes. Single fibres should not be analysed in isolation. Instead, we propose the use of the "object-centre path method" that uses all fibres in a fringe.AcknowledgementsThis project benefited greatly from many discussions with Mark Jessell, Janos Urai and Domingo Aerden. The programs were initially developed at Monash University (Melbourne) with financial support from an Australian Research Council postdoctoral fellowship and subsequent Monash University Logan fellowship to Bons and DFG grant Pa 578/3 to Koehn and DFG grant ur-98-1-1 to Hilgers. |