|
Department of Geology and Applied Geology, University of Glasgow, Glasgow G12 8QQ, UK
In upper-crustal structures, folding by flexural slip leads to the partitioning and ordering of strains, which are commonly expressed by means of faults, fractures and joints. Flexural slip occurs along only some of the numerous layer-to-layer contacts within a sedimentary rock sequence, and these active bedding-plane slip surfaces partition the succession into mechanical units, each of which, although composed of many rock layers, deforms as though it were a single beam. Thus, in upper-crustal flexural-slip folds, the strain domains associated with bending are sharply deliminted by the active slip horizons and also are related to structural position within the beam. Progressive folding leads to the development of additional active slip surfaces and, therefore, to an increased number of mechanical units which each develop bending strains. As a result of this sequence of events, there is a hierarchical overprinting of strains, which leads to considerable complexity in fracture fabrics; nevertheless, order in the fracture patterns is retained. Most petroleum reservoirs appear to be affected by fracture networks created during flexure, and their fluid flow characteristics are probably related to a fracture-dominated, flexural deformation state which is disposed relative to the layering, is inhomogeneous, and is not distributed stochastically throughout the whole rock volume.
This article has been cited by other articles:
![]() |
T. J. Wynn and S. A. Stewart The role of spectral curvature mapping in characterizing subsurface strain distributions Geological Society, London, Special Publications, 2003; 209: 127 - 143. [Abstract] [PDF] |
||||
![]() |
S. J. Jolley, I. H. C. Henderson, A. C. Barnicoat, and N. P. C. Fox Thrust-fracture network and hydrothermal gold mineralization: Witwatersrand Basin, South Africa Geological Society, London, Special Publications, 1999; 155: 153 - 165. [Abstract] [PDF] |
||||
![]() |
G. D. Couples and H. Lewis Effects of interlayer slip in model forced folds Geological Society, London, Special Publications, 1999; 169: 129 - 144. [Abstract] [PDF] |
||||