Abstract
Laboratory data suggest that shallowly buried granitic basement rocks behave in a brittle fashion. Field evidence confirms this suggestion. However, laboratory results suggest that the deformations of sedimentary rocks range from brittle to ductile and that layering may have an important influence on deformation. Field evidence also confirms this suggestion. Using these results to set limits on the behaviors of naturally deformed rocks in the Wyoming Province the analytical work of Hafner (1951) and Sanford (1959) on faulting is tested in naturally deformed areas. Their boundary conditions are mechanically reasonable, out their assumptions are not applicable to both basement and sedimentary rocks. As applied to the deformation of basement rock in the Wyoming Province, the model is a good representation of nature. However, field evidence shows this model does not fit the behavior of the sedimentary rocks which can deform by drape folding until large displacements are achieved. Field measurements determine that the folding within the Paleozoic carbonate section produces no thinning and that the folds have fixed hinges. These two conditions demand a regional detachment in the lower Paleozoic rocks to make a reasonable palinspastic reconstruction of the observed geology. At the fixed hinges there is extreme extension of the rock..
Stearns, David W. (1970). Drape folds over uplifted basement blocks with emphasis on the Wyoming province. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -181215.