Abstract
Faulted drape-folds are produced experimentally at a confining pressure of 1.0 kb, room temperature, and an axial shortening-rate of 10⁻⁴/sec by forcing a block of essentially brittle sandstone (2 by 3 by 12.6 cm) along a lubricated saw cut into three sedimentary layers of Indiana Limestone, Coconino Sandstone and Indiana Limestone (each layer: 0.3 by 3 by 11.3 cm). Internal stress distributions and patters of faults in the deformed sedimentary layers are mapped by (1) petrofabric observations of the locations and orientations of reverse and normal faults, microfractures, and compression and extension axes inferred from orientations of calcite twin lamellae, and (2) analytical solutions of principal-stress trajectories by means of Airy's stress function and predictions of potential faults by means of the Mohr-Coulomb failure criterion. Boundary conditions for the numerical models are similar to those of the experiments. Petrofabric observations show that the orientations of the principal-stress trajectories are nearly independent of the applied displacement along the lower boundary of the sedimentary layers. The solutions of two-dimensional elastic analyses also show that the orientations of principal stresses up to the onset of failure depend only upon the size of the layer (thickness and length) and Poisson's ratio. Modulus of rigidity, Lame's constant, and applied displacement are not significant in determining the orientations of principal stresses.
Min, Kyung Duck (1974). Analytical and petrofabric studies of experimental faulted drape-folds in layered rock specimens. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -172491.