INFLUENCES OF TECTONIC AND GEOMORPHIC PROCESSES ON FAULT SCARP HEIGHT VARIABILITY IN AN EXTENSIONAL TECTONIC TERRANE, TETON FAULT, WYOMING
LiDAR-based mapping of the fault zone indicates that scarp height is affected by glacial geomorphology, mass wasting, and alluvial processes. At a broad scale, vertical separation across scarps increases in the central portion of the fault. At a finer scale, vertical separation of scarps is lower in the floors of deglaciated valleys than on neighboring glacial moraines (e.g., Phelps Lake), reflecting both valley floor processes and younger landform ages. Anomalously high scarps (>15 m vertical separation) are likely an artifact of greater landform age. Landslides influence vertical separation by erosion and burial. Scarps that cut alluvial landforms are typically lower and more diffuse other Teton fault scarps.
The vertical offset of normal fault scarps is expected to systematically increase in the central portion of the fault. However, overall vertical offset of Teton fault scarps increases toward the south. Typical vertical offset is ~12 m from the north end of the fault to the south end of Jackson Lake, ~16 m from Jackson Lake to the south end of Jenny Lake, ~11 m from the south end of Jenny Lake to Granite Canyon. Within the first two of these areas, vertical offsets decrease toward the ends of each. South of Granite Canyon, the fault bifurcates into two strands with typical vertical offset of ~28 m. These anomalously high scarps may be the result of greater landform age or variable offset rates. The transition zones between these four areas may represent boundaries between fault sections or segments.