### Abstract

Folds not only help to determine the orientation and magnitude of shortening, but contain much more information on deformation mechanics, kinematics and rheology. The use of folds for strain analysis requires a first-order quantification of the relationships between parameters that determine fold geometry. We present series of 2-dimensional simulations of single-layer folding under pure and simple shear using the software packages ELLE and BASIL. The orientation of the competent layer, the competence contrast between layer and matrix, the stress exponent of the power-law viscous material as well as the boundary conditions are systematically varied to observe the influence of these parameters on fold development. Analyses of stress heterogeneities show that stress localizations are not regularly distributed at the initial stages of folding. Folding of a competent layer requires lower energy (work) in simple shear than in pure shear conditions.

Original language | English |
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Title of host publication | Mathematics of Planet Earth |

Subtitle of host publication | Proceedings of the 15th Annual Conference of the International Association for Mathematical Geosciences |

Editors | E PardoIguzquiza, C GuardiolaAlbert, J Heredia, L MorenoMerino, JJ Duran, JA VargasGuzman |

Place of Publication | Berlin |

Publisher | Springer-Verlag |

Pages | 763-766 |

Number of pages | 4 |

ISBN (Print) | 978-3-642-32407-9, 978-3-642-32408-6 |

DOIs | |

Publication status | Published - 2014 |

Event | 15th Annual Conference of the International-Association-for-Mathematical-Geosciences (IAMG) - Madrid, Spain Duration: 2 Sep 2013 → 6 Sep 2013 |

### Publication series

Name | Lecture Notes in Earth System Sciences |
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Publisher | Springer-Verlag Berlin |

ISSN (Print) | 2193-8571 |

### Conference

Conference | 15th Annual Conference of the International-Association-for-Mathematical-Geosciences (IAMG) |
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Country | Spain |

Period | 2/09/13 → 6/09/13 |

### Keywords

- kinematical analysis
- single-layer
- folding
- simple shear
- pure shear
- stress
- non-linear rheology

## Cite this

Llorens, M-G., Bons, P. D., Griera, A., & Gomez-Rivas, E. (2014). Mechanics of Fold Development in Pure- and Simple Shear. In E. PardoIguzquiza, C. GuardiolaAlbert, J. Heredia, L. MorenoMerino, JJ. Duran, & JA. VargasGuzman (Eds.),

*Mathematics of Planet Earth: Proceedings of the 15th Annual Conference of the International Association for Mathematical Geosciences*(pp. 763-766). (Lecture Notes in Earth System Sciences). Springer-Verlag. https://doi.org/10.1007/978-3-642-32408-6_164