The initiation and evolution of the transpressional Straight River shear zone, central Fiordland, New Zealand

Daniel S. King, Keith A. Klepeis, Arthur G. Goldstein, George E Gehrels, Geoffrey L. Clarke

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Structural data and U/Pb geochronology on zircon from central Fiordland, New Zealand show the role of pre-existing structural heterogeneities in the kinematic evolution of a newly discovered zone of transpression. The Straight River shear zone consists of steep zones of high strain that are superimposed onto older fabrics across a 10 × 80 km region. The older foliation formed during two periods of tectonism: contraction and magmatism of mostly Carboniferous (∼312-306 Ma) age and Early Cretaceous batholith emplacement ending by 113.4 ± 1.7 Ma followed by extension that ceased by 88.4 ± 1.2 Ma. The primary mechanism for the formation of steep shear zone foliations was the folding of these older fabrics. Conjugate crenulation cleavages associated with the folding record shortening at high angles to the shear zone boundaries. Fold axial surfaces and axial planar cleavages strike parallel to the shear zone with increasing strain as they progressively steepened to subvertical. In most areas, shear sense flips from oblique-sinistral (east-side-down component) to oblique-dextral (west-side-down) across zones of intermediate and high strain. High strain zones display subvertical mineral lineations, steep strike-slip faults and shear sense indicators that record strike-slip motion across the steep lineations. These patterns reflect triclinic transpression characterized by narrow zones of mostly strike-slip deformation and wide zones of mostly contraction. Zones of high strain align with offshore traces of late Tertiary strike-slip faults, suggesting that a previously undocumented component of late Tertiary shortening and strike-slip motion is accommodated within Fiordland.

Original languageEnglish (US)
Pages (from-to)410-430
Number of pages21
JournalJournal of Structural Geology
Volume30
Issue number4
DOIs
StatePublished - Apr 2008

Fingerprint

shear zone
river
transpression
lineation
foliation
strike-slip fault
contraction
folding
crenulation cleavage
batholith
geochronology
cleavage
magmatism
emplacement
zircon
kinematics
fold
Cretaceous
mineral

Keywords

  • Shear zone
  • Strain partitioning
  • Transpression
  • U/Pb geochronology

ASJC Scopus subject areas

  • Geology

Cite this

The initiation and evolution of the transpressional Straight River shear zone, central Fiordland, New Zealand. / King, Daniel S.; Klepeis, Keith A.; Goldstein, Arthur G.; Gehrels, George E; Clarke, Geoffrey L.

In: Journal of Structural Geology, Vol. 30, No. 4, 04.2008, p. 410-430.

Research output: Contribution to journalArticle

King, Daniel S. ; Klepeis, Keith A. ; Goldstein, Arthur G. ; Gehrels, George E ; Clarke, Geoffrey L. / The initiation and evolution of the transpressional Straight River shear zone, central Fiordland, New Zealand. In: Journal of Structural Geology. 2008 ; Vol. 30, No. 4. pp. 410-430.
@article{21c253bb364342078b3b05e441e9999b,
title = "The initiation and evolution of the transpressional Straight River shear zone, central Fiordland, New Zealand",
abstract = "Structural data and U/Pb geochronology on zircon from central Fiordland, New Zealand show the role of pre-existing structural heterogeneities in the kinematic evolution of a newly discovered zone of transpression. The Straight River shear zone consists of steep zones of high strain that are superimposed onto older fabrics across a 10 × 80 km region. The older foliation formed during two periods of tectonism: contraction and magmatism of mostly Carboniferous (∼312-306 Ma) age and Early Cretaceous batholith emplacement ending by 113.4 ± 1.7 Ma followed by extension that ceased by 88.4 ± 1.2 Ma. The primary mechanism for the formation of steep shear zone foliations was the folding of these older fabrics. Conjugate crenulation cleavages associated with the folding record shortening at high angles to the shear zone boundaries. Fold axial surfaces and axial planar cleavages strike parallel to the shear zone with increasing strain as they progressively steepened to subvertical. In most areas, shear sense flips from oblique-sinistral (east-side-down component) to oblique-dextral (west-side-down) across zones of intermediate and high strain. High strain zones display subvertical mineral lineations, steep strike-slip faults and shear sense indicators that record strike-slip motion across the steep lineations. These patterns reflect triclinic transpression characterized by narrow zones of mostly strike-slip deformation and wide zones of mostly contraction. Zones of high strain align with offshore traces of late Tertiary strike-slip faults, suggesting that a previously undocumented component of late Tertiary shortening and strike-slip motion is accommodated within Fiordland.",
keywords = "Shear zone, Strain partitioning, Transpression, U/Pb geochronology",
author = "King, {Daniel S.} and Klepeis, {Keith A.} and Goldstein, {Arthur G.} and Gehrels, {George E} and Clarke, {Geoffrey L.}",
year = "2008",
month = "4",
doi = "10.1016/j.jsg.2007.12.004",
language = "English (US)",
volume = "30",
pages = "410--430",
journal = "Journal of Structural Geology",
issn = "0191-8141",
publisher = "Elsevier Limited",
number = "4",

}

TY - JOUR

T1 - The initiation and evolution of the transpressional Straight River shear zone, central Fiordland, New Zealand

AU - King, Daniel S.

AU - Klepeis, Keith A.

AU - Goldstein, Arthur G.

AU - Gehrels, George E

AU - Clarke, Geoffrey L.

PY - 2008/4

Y1 - 2008/4

N2 - Structural data and U/Pb geochronology on zircon from central Fiordland, New Zealand show the role of pre-existing structural heterogeneities in the kinematic evolution of a newly discovered zone of transpression. The Straight River shear zone consists of steep zones of high strain that are superimposed onto older fabrics across a 10 × 80 km region. The older foliation formed during two periods of tectonism: contraction and magmatism of mostly Carboniferous (∼312-306 Ma) age and Early Cretaceous batholith emplacement ending by 113.4 ± 1.7 Ma followed by extension that ceased by 88.4 ± 1.2 Ma. The primary mechanism for the formation of steep shear zone foliations was the folding of these older fabrics. Conjugate crenulation cleavages associated with the folding record shortening at high angles to the shear zone boundaries. Fold axial surfaces and axial planar cleavages strike parallel to the shear zone with increasing strain as they progressively steepened to subvertical. In most areas, shear sense flips from oblique-sinistral (east-side-down component) to oblique-dextral (west-side-down) across zones of intermediate and high strain. High strain zones display subvertical mineral lineations, steep strike-slip faults and shear sense indicators that record strike-slip motion across the steep lineations. These patterns reflect triclinic transpression characterized by narrow zones of mostly strike-slip deformation and wide zones of mostly contraction. Zones of high strain align with offshore traces of late Tertiary strike-slip faults, suggesting that a previously undocumented component of late Tertiary shortening and strike-slip motion is accommodated within Fiordland.

AB - Structural data and U/Pb geochronology on zircon from central Fiordland, New Zealand show the role of pre-existing structural heterogeneities in the kinematic evolution of a newly discovered zone of transpression. The Straight River shear zone consists of steep zones of high strain that are superimposed onto older fabrics across a 10 × 80 km region. The older foliation formed during two periods of tectonism: contraction and magmatism of mostly Carboniferous (∼312-306 Ma) age and Early Cretaceous batholith emplacement ending by 113.4 ± 1.7 Ma followed by extension that ceased by 88.4 ± 1.2 Ma. The primary mechanism for the formation of steep shear zone foliations was the folding of these older fabrics. Conjugate crenulation cleavages associated with the folding record shortening at high angles to the shear zone boundaries. Fold axial surfaces and axial planar cleavages strike parallel to the shear zone with increasing strain as they progressively steepened to subvertical. In most areas, shear sense flips from oblique-sinistral (east-side-down component) to oblique-dextral (west-side-down) across zones of intermediate and high strain. High strain zones display subvertical mineral lineations, steep strike-slip faults and shear sense indicators that record strike-slip motion across the steep lineations. These patterns reflect triclinic transpression characterized by narrow zones of mostly strike-slip deformation and wide zones of mostly contraction. Zones of high strain align with offshore traces of late Tertiary strike-slip faults, suggesting that a previously undocumented component of late Tertiary shortening and strike-slip motion is accommodated within Fiordland.

KW - Shear zone

KW - Strain partitioning

KW - Transpression

KW - U/Pb geochronology

UR - http://www.scopus.com/inward/record.url?scp=41249084647&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=41249084647&partnerID=8YFLogxK

U2 - 10.1016/j.jsg.2007.12.004

DO - 10.1016/j.jsg.2007.12.004

M3 - Article

AN - SCOPUS:41249084647

VL - 30

SP - 410

EP - 430

JO - Journal of Structural Geology

JF - Journal of Structural Geology

SN - 0191-8141

IS - 4

ER -