Three-dimensional Distinct Element Method modelling of the growth of normal faults in layered sequences

Autor(en)

Martin P. J. Schöpfer, Conrad Childs, Tom Manzocchi, John J. Walsh

Abstrakt

The growth of normal faults in mechanically layered sequences is numerically modelled using three-dimensional Distinct Element Method (DEM) models, in which rock comprises an assemblage of bonded spherical particles. Faulting is induced by movement on a pre-defined normal fault at the model base whilst a constant confining pressure is maintained by applying forces to particles lying at the model top. The structure of the modelled fault zones and its dependency on confining pressure, sequence (net:gross) and fault obliquity are assessed using various new techniques that allow (a) visualization of faulted horizons, (b) quantification of throw partitioning and (c) determination of the fault zone throw beyond which theoretical juxtaposition sealing occurs along the entire zone length. The results indicate that fault zones become better localized with increasing throw and confinement. The mechanical stratigraphy has a profound impact on fault zone structure and localization: both low and high net:gross sequences lead to wide and relatively poorly localized faults. Fault strands developing above oblique-slip normal faults form, on average, normal to the greatest infinitesimal stretching direction in transtensional zones. The model results are consistent with field observations and results from physical experiments.

Organisation(en)

Institut für Geologie

Externe Organisation(en)

University College Dublin

Journal

Geological Society Special Publications

Band

439

Seiten

307-332

Anzahl der Seiten

26

DOI

https://doi.org/10.1144/SP439.17

Publikationsdatum

2017

Peer-reviewed

Ja

ÖFOS 2012

105124 Tektonik

ASJC Scopus Sachgebiete

Water Science and Technology, Ocean Engineering, Geology

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/055c1724-d92f-4977-9d69-d5a7b32a9d4f