Correlation between cumulative horizontal extension and strike-slip displacement in releasing bends: Discrete element analysis

IF 2.6 2区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Structural Geology Pub Date : 2025-03-13 DOI:10.1016/j.jsg.2025.105406

Lunyan Wei , Guiting Hou , Shangxin Wu , Jinkai Xia

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引用次数: 0

Abstract

Releasing bends are structural features formed by localized extension along strike-slip fault systems. Synclines, pull-apart basins, and extensional strike-slip duplexes develop mainly at releasing bends. Exploring the correlation between strike-slip displacement and cumulative horizontal extension displacement of transtensional structures could be useful for estimating strike-slip displacement when horizontal extension displacement (horizontal fault offsets of en echelon normal faults) is known. The formation and evolution of the releasing bend can be effectively simulated by 2D particle discrete element method. The microscopic parameters of the particles, such as effective modulus and stiffness ratio, are calibrated to model Young's modulus and Poisson's ratio. Six setups of simple strike-slip geometry and releasing bend geometries with different fault separations (the distances between adjacent faults) are then designed. The modelling results reveal a quantitative correlation between the strike-slip displacement L, the cumulative horizontal extension displacement

\sum_{1}^{n} \frac{T_{i}}{\sin θ_{i}}

, and the fracture propagation angle θ:

\sum_{1}^{n} \frac{T_{i}}{\sin θ_{i}} = k * L

. The k value serves as a comprehensive coefficient to take complex factors into account. In our models, the k values range from 0.9 to 1.6 and are greater for soft rocks than for hard rocks. This quantitative correlation shows a good fit with several natural examples in similar strike-slip or pull-apart tectonic settings, effectively supporting our conclusion.

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来源期刊

Journal of Structural Geology 地学-地球科学综合

CiteScore

6.00

自引率

19.40%

发文量

192

审稿时长

15.7 weeks

期刊介绍： The Journal of Structural Geology publishes process-oriented investigations about structural geology using appropriate combinations of analog and digital field data, seismic reflection data, satellite-derived data, geometric analysis, kinematic analysis, laboratory experiments, computer visualizations, and analogue or numerical modelling on all scales. Contributions are encouraged to draw perspectives from rheology, rock mechanics, geophysics,metamorphism, sedimentology, petroleum geology, economic geology, geodynamics, planetary geology, tectonics and neotectonics to provide a more powerful understanding of deformation processes and systems. Given the visual nature of the discipline, supplementary materials that portray the data and analysis in 3-D or quasi 3-D manners, including the use of videos, and/or graphical abstracts can significantly strengthen the impact of contributions.