Constraining the timing of shale detachment faulting: a geochemical approach

Rowan L. Hansberry, Horst Zwingmann, Stefan Löhr, Alan S. Collins, Rosalind C. King, Christopher K. Morley, Russell N. Drysdale

Research output: Contribution to journalArticleResearchpeer-review

Abstract

K-Ar dating of illite in fault gouges is a useful tool for constraining the timing of brittle fault movement; however, this can be problematic in fault gouges hosted in clay-rich rocks due to the influence of host-rock material. Therefore, this study employs a multianalytical geochemical approach to unravel the influence of host-rock mineralogy, as well as fault zone development, on ages from fault-gouge samples in a shale detachment zone. K-Ar dating of the ≥2 µm fraction of 6 samples from the Sap Bon Formation detachment zone and associated fault zones in the Khao Khwang fold-thrust belt of central Thailand yielded an age range of 262 ± 5.4 to 208 ± 4.6 Ma. Carbon and oxygen stable isotope
analysis along with X-ray diffraction mineralogy indicate that the samples with the youngest K-Ar ages are characterized by higher grade clay mineralogy, and hotter, orogenic fluid temperatures. Using these proxies and comparison to existing geochronology of the study area, we correlated K-Ar illite ages to one of three stages of fault zone evolution: detrital, diagenetic (burial), and authigenic (fault movement). The youngest K-Ar dates in the Sap Bon Formation are contemporaneous with recently published zircon province data indicating that faulting and detachment zone formation in the Sap Bon Formation were occurring by the mid-Late Triassic, with deformation continuing as late as the Rhaetian.
LanguageEnglish
Article numberL612.1
Pages431-440
Number of pages10
JournalLithosphere
Volume9
Issue number3
DOIs
Publication statusPublished - 1 Jun 2017

Fingerprint

fault gouge
shale
faulting
fault zone
mineralogy
illite
host rock
clay
Rhaetian
geochronology
zircon
Triassic
thrust
X-ray diffraction
fold
oxygen
fluid
carbon
rock
temperature

Cite this

Hansberry, R. L., Zwingmann, H., Löhr, S., Collins, A. S., King, R. C., Morley, C. K., & Drysdale, R. N. (2017). Constraining the timing of shale detachment faulting: a geochemical approach. Lithosphere, 9(3), 431-440. [L612.1]. https://doi.org/10.1130/L612.1
Hansberry, Rowan L. ; Zwingmann, Horst ; Löhr, Stefan ; Collins, Alan S. ; King, Rosalind C. ; Morley, Christopher K. ; Drysdale, Russell N. / Constraining the timing of shale detachment faulting : a geochemical approach. In: Lithosphere. 2017 ; Vol. 9, No. 3. pp. 431-440.
@article{c2ba759112f648bdacacbde82ea5645f,
title = "Constraining the timing of shale detachment faulting: a geochemical approach",
abstract = "K-Ar dating of illite in fault gouges is a useful tool for constraining the timing of brittle fault movement; however, this can be problematic in fault gouges hosted in clay-rich rocks due to the influence of host-rock material. Therefore, this study employs a multianalytical geochemical approach to unravel the influence of host-rock mineralogy, as well as fault zone development, on ages from fault-gouge samples in a shale detachment zone. K-Ar dating of the ≥2 µm fraction of 6 samples from the Sap Bon Formation detachment zone and associated fault zones in the Khao Khwang fold-thrust belt of central Thailand yielded an age range of 262 ± 5.4 to 208 ± 4.6 Ma. Carbon and oxygen stable isotopeanalysis along with X-ray diffraction mineralogy indicate that the samples with the youngest K-Ar ages are characterized by higher grade clay mineralogy, and hotter, orogenic fluid temperatures. Using these proxies and comparison to existing geochronology of the study area, we correlated K-Ar illite ages to one of three stages of fault zone evolution: detrital, diagenetic (burial), and authigenic (fault movement). The youngest K-Ar dates in the Sap Bon Formation are contemporaneous with recently published zircon province data indicating that faulting and detachment zone formation in the Sap Bon Formation were occurring by the mid-Late Triassic, with deformation continuing as late as the Rhaetian.",
author = "Hansberry, {Rowan L.} and Horst Zwingmann and Stefan L{\"o}hr and Collins, {Alan S.} and King, {Rosalind C.} and Morley, {Christopher K.} and Drysdale, {Russell N.}",
year = "2017",
month = "6",
day = "1",
doi = "10.1130/L612.1",
language = "English",
volume = "9",
pages = "431--440",
journal = "Lithosphere",
issn = "1941-8264",
publisher = "Geological Society of America",
number = "3",

}

Hansberry, RL, Zwingmann, H, Löhr, S, Collins, AS, King, RC, Morley, CK & Drysdale, RN 2017, 'Constraining the timing of shale detachment faulting: a geochemical approach', Lithosphere, vol. 9, no. 3, L612.1, pp. 431-440. https://doi.org/10.1130/L612.1

Constraining the timing of shale detachment faulting : a geochemical approach. / Hansberry, Rowan L.; Zwingmann, Horst; Löhr, Stefan; Collins, Alan S.; King, Rosalind C.; Morley, Christopher K.; Drysdale, Russell N.

In: Lithosphere, Vol. 9, No. 3, L612.1, 01.06.2017, p. 431-440.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Constraining the timing of shale detachment faulting

T2 - Lithosphere

AU - Hansberry, Rowan L.

AU - Zwingmann, Horst

AU - Löhr, Stefan

AU - Collins, Alan S.

AU - King, Rosalind C.

AU - Morley, Christopher K.

AU - Drysdale, Russell N.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - K-Ar dating of illite in fault gouges is a useful tool for constraining the timing of brittle fault movement; however, this can be problematic in fault gouges hosted in clay-rich rocks due to the influence of host-rock material. Therefore, this study employs a multianalytical geochemical approach to unravel the influence of host-rock mineralogy, as well as fault zone development, on ages from fault-gouge samples in a shale detachment zone. K-Ar dating of the ≥2 µm fraction of 6 samples from the Sap Bon Formation detachment zone and associated fault zones in the Khao Khwang fold-thrust belt of central Thailand yielded an age range of 262 ± 5.4 to 208 ± 4.6 Ma. Carbon and oxygen stable isotopeanalysis along with X-ray diffraction mineralogy indicate that the samples with the youngest K-Ar ages are characterized by higher grade clay mineralogy, and hotter, orogenic fluid temperatures. Using these proxies and comparison to existing geochronology of the study area, we correlated K-Ar illite ages to one of three stages of fault zone evolution: detrital, diagenetic (burial), and authigenic (fault movement). The youngest K-Ar dates in the Sap Bon Formation are contemporaneous with recently published zircon province data indicating that faulting and detachment zone formation in the Sap Bon Formation were occurring by the mid-Late Triassic, with deformation continuing as late as the Rhaetian.

AB - K-Ar dating of illite in fault gouges is a useful tool for constraining the timing of brittle fault movement; however, this can be problematic in fault gouges hosted in clay-rich rocks due to the influence of host-rock material. Therefore, this study employs a multianalytical geochemical approach to unravel the influence of host-rock mineralogy, as well as fault zone development, on ages from fault-gouge samples in a shale detachment zone. K-Ar dating of the ≥2 µm fraction of 6 samples from the Sap Bon Formation detachment zone and associated fault zones in the Khao Khwang fold-thrust belt of central Thailand yielded an age range of 262 ± 5.4 to 208 ± 4.6 Ma. Carbon and oxygen stable isotopeanalysis along with X-ray diffraction mineralogy indicate that the samples with the youngest K-Ar ages are characterized by higher grade clay mineralogy, and hotter, orogenic fluid temperatures. Using these proxies and comparison to existing geochronology of the study area, we correlated K-Ar illite ages to one of three stages of fault zone evolution: detrital, diagenetic (burial), and authigenic (fault movement). The youngest K-Ar dates in the Sap Bon Formation are contemporaneous with recently published zircon province data indicating that faulting and detachment zone formation in the Sap Bon Formation were occurring by the mid-Late Triassic, with deformation continuing as late as the Rhaetian.

UR - http://purl.org/au-research/grants/arc/DP120101460

UR - http://purl.org/au-research/grants/arc/FT120100340

UR - http://www.scopus.com/inward/record.url?scp=85019838536&partnerID=8YFLogxK

U2 - 10.1130/L612.1

DO - 10.1130/L612.1

M3 - Article

VL - 9

SP - 431

EP - 440

JO - Lithosphere

JF - Lithosphere

SN - 1941-8264

IS - 3

M1 - L612.1

ER -

Hansberry RL, Zwingmann H, Löhr S, Collins AS, King RC, Morley CK et al. Constraining the timing of shale detachment faulting: a geochemical approach. Lithosphere. 2017 Jun 1;9(3):431-440. L612.1. https://doi.org/10.1130/L612.1