La cinemática del plegamientoalgunas claves geométricas para su interpretación

  1. Canto Toimil, Noel 1
  2. Aller Manrique, Jesús A. 1
  3. Bastida Ibáñez, Fernando 1
  4. Bobillo Ares, Nilo Carlos 1
  1. 1 Universidad de Oviedo
    info

    Universidad de Oviedo

    Oviedo, España

    ROR https://ror.org/006gksa02

Zeitschrift:
Trabajos de geología

ISSN: 0474-9588

Datum der Publikation: 2004

Nummer: 24

Seiten: 9-41

Art: Artikel

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Andere Publikationen in: Trabajos de geología

Zusammenfassung

Computer modeIling of fold profiles formed by a specific folding mechanism is possible when the equations to find transformation relationships from points of the initial configuration to points of the folded configuration of the layer are known. From these equations, folds formed by the successive or simultaneous superposition of tangential longitudinal strain, flexural flow and several types of homogeneous strain (layer shortening, compaction, and fold flattening parallel or perpendicular to the axial trace) have been modelled. The geometry and strain pattern of the theoretical folds allow predictions about the characteristics of natural folds formed by the above mechanisms. The strain state in the folded layer is a typical feature of every mechanism or mechanism superposition and it can be described by two types of curves, which show the variation of the major axis plunge of the strain ellipse and the variation of the aspect ratio of this ellipse with the layer dip. Tangential longitudinal strain is the only mechanism analysed that produces different curves for the two boundaries of the folded layer. Ramsay's classification or classifications based on parameters derived from it also give results specific for every folding mechanism or mechanism superposition. Analysis of folding mechanisms that operated in a specific natural fold can be made by trial and error modelling a fold with the same geometrical characteristics as the natural fold. The geometrical features to be analysed in the latter are those involved in the modelling. In natural folds with cleavage, an approach to the curve of the majar axis plunge of the strain ellipse against the layer dip can be obtained by measuring the dip variation of the cleavage as a function of the layer dip. The greatest problem in the kinematical analysis of folding is posed by the difficulty of obtaining strain measurements in folded rocks.

Bibliographische Referenzen

  • Aller, J., Bastida, F., Toimil, N. C. y Bobillo-Ares, N. C. (2004): The use of conic sections for the geometrical analysis of folded surface profiles. Tectonophysics,379:239-254.
  • Bastida, F., Aller, J.y Bobillo-Ares, N. C. (1999): Geometrical analysis of folded surfaces using simple functions. Journal of Structural Geology,21:729-742.
  • Bastida, F., Bobillo-Ares, N. C., Aller, J. y Toimil, N. C. (2003): Analysis of folding by superposition of strain patterns. Journal of Structural Geology, 25:1121-1139.
  • Billings, M. P. (1954): Structural Geology, 2.ª ed. Prentice Hall, Englewood Cliffs, New Jersey, 514 pp.
  • Biot, M. A. (1961): Theory of folding of stratified viscoelastic media and its implications in tectonics and orogenesis. Geological Society America Bulletin, 72:1595-1620.
  • Biot, M. A. (1965): Mechanics of the incremental deformations. Wiley, Nueva York, 504 pp.
  • Bobillo-Ares, N. C., Bastida, F. y Aller, J. (2000). On tangential longitudinal strain folding. Tectonophysics,319:53-68.
  • Bobillo-Ares, N. C., Toimil, N. C., Aller, J. y Bastida, F., (2004): ‘FoldModeler’: a tool for the geometrical and kinematical analysis of folds. Computers & Geosciences, 30:147-159.
  • Brannan, D. A., Esplen, M. F. y Gray, J. J. (1999): Geometry. Cambridge University Pres, Cambridge, 514 pp.
  • Chapple, W. M. (1968): A mathematical theory of finite-amplitude rock-folding. Geological Society America Bulletin, 79:47-68.
  • De Sitter, L. U. (1965): Structural Geology, 2.ª ed. McGraw-Hill Book Co., Nueva York, 551 pp.
  • Dietrich, D. y Casey, M. (1989): A new tectonic model for the Helvetic nappes. En: Alpine Tectonics (M.P. Coward, D. Dietrich, y R.G. Park, Eds.). Geological Society Special Publication, 45, Oxford, 47-63.
  • Dieterich, J. H. (1969): Origin of cleavage in folded rocks. American Journal of Science, 267:155-165.
  • Fleuty, M. J. (1964): The description of folds. Proceedings Geological Association of London, 75:461-492.
  • Fleuty, M. J. (1987): Folds and folding. In: Seyfert, C.K. (Ed.), The Encyclopedia of Structural Geology and plate tectonics.Van Nostrand Reinhold, New York, 249-270.
  • Gairola, V. K. (1978): Three-dimensional strain in fold-hinge zone. Tectonophysics, 41:291-319.
  • Hatcher, Jr. R. D. (1995). Structural Geology: principles, concepts and problems.Prentice Hall (2nd ed.), New Jersey, 525 pp.
  • Hudleston, P. J. (1973): Fold morphology and some geometrical implications of theories of fold development. Tectonophysics 16:1-46.
  • Hudleston, P. J. (1977): Similar folds, recumbent folds and gravity tectonics in ice and rocks. Journal of Geology,85:113-122.
  • Johnson, A. M. y Fletcher, R. C. (1994): Folding of viscous layers. Columbia University Press, Nueva York, 461 pp.
  • Kuenen, P. U. y De Sitter, L. U. (1938): Experimental investigation into the mechanism of folding. Leidse Geologische Mededelingen, 10:271-240.
  • Mattauer, M. (1973): Les déformations des matériaux de l´écorce terrestre. Hermann, París, 493 pp.
  • Mukhopadhyay, D. (1965): Effects of compression on concentric folds and mechanism of similar folding. Journal of the Geological Society of India, 6:27-41.
  • Price, N. J. y Cosgrove, J. W. (1990): Analysis of geological structures. Cambridge University Press, Cambridge, 502 pp.
  • Ramsay, J. G., (1962): The geometry and mechanics of formation of “similar” type folds. Journal of Geology,70:309-327.
  • Ragan, D. M. (1969): Structures at the base of an ice fall. Journal of Geology, 77: 647-667.
  • Ramberg, H. (1960): Relationship between length of arc and thickness of ptygmatically folded veins. American Journal of Science, 258:36-46.
  • Ramsay, J. G. (1967): Folding and fracturing of rocks.McGraw-Hill Book, New York, 568 pp.
  • Ramsay, J. G. y Huber, M. I. (1987): Modern structural geology, Volume 2: Folds and Fractures.Academic Press, London, 392 pp.
  • Ramsay, J. G., Casey, M. y Kligfield, R. (1983): Role of shear in development of Helvetic fold-thrust belt of Swizerland. Geology, 11:439-442.
  • Shimamoto, T. y Hara, Y. (1976): Geometry and strain distribution of single-layer fold. Tectonophysics,30:1-34.
  • Stabler, C. L. (1968): Simplified Fourier analysis of fold shapes. Tectonophysics,6:343-350.
  • Stoc̆es, B. y White, C. H. (1935): Structural geology with special reference to economic deposits. Macmillan and Co., Londres, 460 pp.
  • Stowe, C. W. (1988): Application of Fourier analysis for computer representation of fold profiles. Tectonophysics, 156:303-311.
  • Twiss, R. J. (1988): Description and classification of folds in single surfaces. Journal of Structural Geology, 10:607-626.
  • Wood, D. S. (1974): Current views of the development of slaty cleavage. Annual Review of Earth and Planetary Sciences, 2:369-401.
Fuente de los datos: Dialnet