10.6084/m9.figshare.3454463.v1
C.L. Kirkland
C.L.
Kirkland
G.I. Alsop
G.I.
Alsop
A.R. Prave
A.R.
Prave
The brittle evolution of a major strike-slip fault associated with granite emplacement: a case study of the Leannan Fault,
NW Ireland
Geological Society of London
2016
joint
rotation
Malin Head Granite
NW Ireland
Malin Head region
Subsequent sinistral fractures
fault
Great Glen Fault zone
NE
granite emplacement
F 1
ductile sinistral shearing
Tullagh Point Granite
intrusion
Leannan Fault
Geology
2016-06-21 12:08:04
Dataset
https://geolsoc.figshare.com/articles/dataset/The_brittle_evolution_of_a_major_strike-slip_fault_associated_with_granite_emplacement_a_case_study_of_the_Leannan_Fault___NW_Ireland/3454463
<p>NE–SW-trending sinistral strike-slip deformation is widespread throughout the Highlands of Scotland and NW Ireland and has
been interpreted as a response to the subduction of Iapetus and continental collision. The southwestern continuation of the
Great Glen Fault zone is marked in NW Ireland by the Leannan Fault. Field evidence derived from the Tullagh Point Granite
indicates its intrusion along the fault during ductile sinistral shearing. U–Th–Pb zircon geochronology yields a crystallization
age of 422 ± 2 Ma for this granite. Detailed analysis of fracture patterns throughout the Malin Head region demonstrates that
sinistral fractures (F<sub>1</sub>) developed at an acute angle to the main fault strands. These fractures display oblique internal alignment of K-feldspar
and are overprinted by dilatational quartz-filled joints at a similar orientation. The trend of these joints is consistent
with <em>c</em>. 90° rotation of the σ<sub>1</sub> axes relative to F<sub>1</sub> as a result of intrusion of the Malin Head Granite dated at 412 ± 3 Ma. Subsequent sinistral fractures developed after dissipation
of granite-related forces. They define an anticlockwise rotation of the regional σ<sub>1</sub> and moved under a different stress tensor from F<sub>1</sub>. It is concluded that the Leannan Fault moved sinistrally at <em>c</em>. 422 Ma and after <em>c</em>. 412 Ma, and that granite emplacement had pronounced effects on the fault kinematics.
</p>