Shear folding in low-grade metasedimentary rocks - reverse shear along cleavage at a high angle to the maximum compressive stress
- 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.
Author details: | Patrick A. Meere, Kieran F. Mulchrone, Martin Timmerman |
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DOI: | https://doi.org/10.1130/G34150.1 |
ISSN: | 0091-7613 |
Title of parent work (English): | Geology |
Publisher: | American Institute of Physics |
Place of publishing: | Boulder |
Publication type: | Article |
Language: | English |
Year of first publication: | 2013 |
Publication year: | 2013 |
Release date: | 2017/03/26 |
Volume: | 41 |
Issue: | 8 |
Number of pages: | 4 |
First page: | 879 |
Last Page: | 882 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
Peer review: | Referiert |
Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |