Along-strike fault core thickness variations of a fault in poorly lithified sediments, Miri (Malaysia)
Sosio De Rosa, Silvia and Shipton, Zoe K. and Lunn, Rebecca J. and Kremer, Yannick and Murray, Titus (2018) Along-strike fault core thickness variations of a fault in poorly lithified sediments, Miri (Malaysia). Journal of Structural Geology, 116. pp. 189-206. ISSN 0191-8141 (https://doi.org/10.1016/j.jsg.2018.08.012)
Preview |
Text.
Filename: De_Rosa_etal_JSG_2018_Along_strike_fault_core_thickness_variations_of_a_fault.pdf
Final Published Version License: Download (14MB)| Preview |
Abstract
Fault resistance to across-fault fluid flow is as strong as its weakest point. Processes that determine patches of the fault surface containing transmissible fault rocks must be taken into account to produce reliable predictions of cross fault fluid flow. We use a study site in Miri as a natural laboratory to investigate in detail the fault core thickness variations along-strike and down dip and to quantify the risk of discontinuities in the clay-rich fault core. Five fault core types have been identified: foliated clay-rich fault core, chaotic clay-rich fault core, attenuated clay-rich fault core, sandy anastomosing shears and sandy breccia. The sandy fault rocks are likely to have lower capillary entry pressure, and higher permeability than the clay-rich rock, so could represent potential cross-fault flow pathways. We performed a geostatistical analysis, showing a correlation over 3 m scale, suggesting the presence of ‘patches’ of thin and thick fault core generally less than 3m in length. We interpret this as superimposition of two (or more) different deformation processes at a smaller and larger scale. We speculate on the processes that could produce the observed distribution of thickness and composition, in particular processes that could have disrupted the through-going clay-rich core.
ORCID iDs
Sosio De Rosa, Silvia ORCID: https://orcid.org/0000-0002-4455-0464, Shipton, Zoe K. ORCID: https://orcid.org/0000-0002-2268-7750, Lunn, Rebecca J. ORCID: https://orcid.org/0000-0002-4258-9349, Kremer, Yannick ORCID: https://orcid.org/0000-0002-5686-6351 and Murray, Titus;-
-
Item type: Article ID code: 65335 Dates: DateEvent30 November 2018Published25 August 2018Published Online23 August 2018Accepted28 March 2018SubmittedSubjects: Science > Geology Department: Faculty of Engineering > Civil and Environmental Engineering Depositing user: Pure Administrator Date deposited: 31 Aug 2018 13:57 Last modified: 18 Sep 2024 00:44 Related URLs: URI: https://strathprints.strath.ac.uk/id/eprint/65335