Peer-Reviewed Journal Details
Mandatory Fields
Meere, PA;Mulchrone, KF;Timmerman, M
2013
August
Geology
Shear folding in low-grade metasedimentary rocks: Reverse shear along cleavage at a high angle to the maximum compressive stress
Validated
Optional Fields
PRESSURE SOLUTION DEFORMATION VARISCIDES IRELAND STRAIN FAULTS
41
879
882
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.
BOULDER
0091-7613
10.1130/G34150.1
Grant Details