TY  - JOUR
A1  - Meere, Patrick A.
A1  - Mulchrone, Kieran F.
A1  - Timmerman, Martin
T1  - Shear folding in low-grade metasedimentary rocks - reverse shear along cleavage at a high angle to the maximum compressive stress
JF  - Geology
N2  - Shear folding, which is also referred to as slip folding, involves shear along planes that are oriented approximately parallel to the axial plane of the fold structure. These planes, which are typically axial-planar cleavage planes, facilitate high-angle reverse slip leading to fold limb rotation and amplification. This study builds on recent advances in our understanding of the role of weak fault zones in facilitating slip on misoriented faults; i.e., faults at a high angle to the maximum principal tectonic stress (sigma(1)). Analysis of folded marine sedimentary rocks from the Variscan of southern Ireland provides unambiguous microstructural evidence for reverse shear on chemically weakened cleavage domains. Significant silica loss in these cleavage domains, and as a consequence marked mechanical weakening, is seen as the primary cause for the reverse slip associated with the shear folding of these sedimentary rocks.
Y1  - 2013
U6  - https://doi.org/10.1130/G34150.1
SN  - 0091-7613
VL  - 41
IS  - 8
SP  - 879
EP  - 882
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Meere, Patrick A.
A1  - Mulchrone, Kieran F.
A1  - McCarthy, Dave J.
A1  - Timmerman, Martin Jan
A1  - Dewey, John F.
T1  - Prelithification and synlithification tectonic foliation development in
a clastic sedimentary sequence
JF  - Geology
N2  - The current view regarding the timing of regionally developed penetrative tectonic fabrics in sedimentary rocks is that their development postdates lithification of those rocks. In this case, fabric development is achieved by a number of deformation mechanisms, including grain rigid body rotation, crystal-plastic deformation, and pressure solution. The latter is believed to be the primary mechanism responsible for the domainal structure of cleavage in low-grade metamorphic rocks. In this study we combine field observations with strain studies to characterize considerable (>50%) Acadian crustal shortening in a Devonian clastic sedimentary sequence from southwest Ireland. Despite these high levels of shortening there is a marked absence of the domainal cleavage structure and intraclast deformation that are expected with this level of deformation. Fabrics in these rocks are predominantly a product of rigid body rotation and repacking of extraformational clasts during deformation of a clastic sedimentary sequence before lithification was complete.
Y1  - 2016
U6  - https://doi.org/10.1130/G37587.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 44
SP  - 291
EP  - 294
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - GEN
A1  - Meere, Patrick A.
A1  - Mulchrone, Kieran F.
A1  - McCarthy, David J.
A1  - Timmerman, Martin Jan
A1  - Dewey, John F.
T1  - Prelithification and synlithification tectonic foliation development in a clastic sedimentary sequence
T2  - Geology
Y1  - 2016
U6  - https://doi.org/10.1130/G38103Y.1
SN  - 0091-7613
SN  - 1943-2682
VL  - 44
SP  - E397
EP  - E397
PB  - American Institute of Physics
CY  - Boulder
ER  -