GEOMETRY AND TECTONIC IMPLICATIONS OF THE NORTHERN SNAKE RANGE FOLD AND THRUST SYSTEM

The northern Snake Range metamorphic core complex is an ideal natural laboratory for investigating the Mesozoic contractional history associated with most Cordilleran metamorphic core complexes. Previous work in the area suggests the continental shelf stratigraphy of the northern Snake Range experienced depths of approximately twice the original stratigraphic thickness of 10 km. New mapping and structural data from the western flank of the range suggest a complex interplay between map-scale thrust faults and folds may be responsible for the deep burial of lower plate rocks. This hypothesis is being tested through restorable cross section construction and U-Pb zircon dating of local cross cutting intrusions. In addition to assessing burial depths, microstructural analyses of quartzite units located along the western flank are being conducted to quantify the type, orientation, and magnitude of strain experienced by the lower plate rocks. These results will be compared to the highly strained quartzite units that characterize the eastern flank of the range.