Strain analysis of deformed granitic rocks (Helikian), Muskoka District, Ontario
作者： Donald M Davidson
DOI: 10.1016/0191-8141(83)90043-3
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摘要: Abstract Three-dimensional analysis of irrotational, longitudinal, finite strain was carried out on samples from a crescentic sheet which intruded and deformed with host gneiss unit probable Helikian age. Analytical methods were compared using feldspar grains representing four ideal degrees intensity observed in the porphyritic sheet. The polar plot R f / φ , s proved most reliable sensitive. Data derived fabric at 38 sites units suggest two-stage deformational sequence. first stage produced recumbent, isoclinal, similar (class 2) folds northwest-trending hinge surface traces. This fold form modified during second to produce an overall type 2 interference pattern. upright, open buckle as well resultant currently observed. Strain confirms general geometries model, also documents competency contrasts between matrix increased magnitude. Deformation involved modification low magnitude ( ϵ = 0.3) k value near unity magnitudes 2.6 0.6. Matrix intensities are consistently higher than those markers variation is related differences grains. Fabric anisotropy accounts for gradient gneiss.
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