Browse by author
Lookup NU author(s): Dr Mark IrelandORCiD, Professor Richard DaviesORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Polygonal fault systems, sometimes termed layer-bound faults, are extraordinary features of many fine-grained sedimentary successions and have been described in a significant number of sedimentary basins over the last two decades. Their formation represents an important mechanism by which fine-grained sediments compact often resulting in a variety of complex patterns for which several controlling factors have been proposed. Here three-dimensional seismic data from the North West Shelf of Australia are used to interpret previously undescribed characteristics of layer-bound fault systems where systematic horst and graben structures are the dominant structural style. Conjugate fault pairs, which form the horsts and grabens, frequently have a systematic spacing with graben bounding faults exhibiting a spacing of half that of the horst bounding faults. This systematic spacing of fault pairs indicates, 1) the presence of a mechanically weaker layer at the base of the fault system and 2) that the horizontal shortening required by the volume loss due to compaction can be accommodated without reaching saturation with respect to fault intensity. Furthermore, topological analysis indicates that areas with different patterns also have different intersection and branch characteristics, and these differences suggest that the growth of layer-bound faults is not explained by a single model. The findings have implications for the genesis and growth of layer-bound fault systems and the potential for cross stratal fluid flow.
Author(s): Ireland MT, Morley CK, Davies RJ
Publication type: Article
Publication status: Published
Journal: Basin Research
Year: 2021
Volume: 33
Issue: 5
Pages: 2745-2762
Print publication date: 03/09/2021
Online publication date: 09/07/2021
Acceptance date: 24/06/2021
Date deposited: 29/10/2021
ISSN (print): 0950-091X
ISSN (electronic): 1365-2117
Publisher: Wiley
URL: https://doi.org/10.1111/bre.12582
DOI: 10.1111/bre.12582
Altmetrics provided by Altmetric
