Titel: Postglacial slip distribution along the Teton normal fault, northeastern Basin-and-Range Province (Wyoming, USA) derived from tectonically offset geomorphological features
Andrea Hampel1, Ralf Hetzel2, Maria-Sophie Erdmann2
1Institut fuer Geologie, Leibniz Universitaet Hannover; 2Institut fuer Geologie und Palaeontologie, Westfaelische Wilhelms-Universitaet Muenster
Veranstaltung: GeoKarlsruhe 2021
Along the eastern front of the Teton Range, northeastern Basin-and-Range Province, well-preserved fault scarps that formed across moraines, river terraces and other geomorphological features indicate that multiple earthquakes ruptured the range-bounding Teton normal fault after the Last Glacial Maximum (LGM). Here we use high-resolution digital elevation models derived from Lidar data to determine the vertical slip distribution along-strike of the Teton fault from 54 topographic profiles across tectonically offset geomorphological features along the entire Teton Range front. (Hampel et al., Geosphere, in press, doi.org/10.1130/GES02370.1). We find that offset LGM moraines and glacially striated surfaces show higher vertical displacements than younger fluvial terraces, which formed at valley exits upstream of LGM terminal moraines. Our results reveal that the tectonic offsets preserved in the faults scarps are post-LGM in age and that the postglacial slip distribution along-strike of the Teton fault is asymmetric with respect to the Teton Range center, with the maximum vertical displacements (27-23 m) being located north of Jenny Lake and along the southwestern shore of Jackson Lake. As indicated by earlier 3D numerical models, this asymmetric slip distribution results from postglacial unloading of the Teton fault, which experienced loading by the Yellowstone ice cap and valley glaciers in the Teton Range during the last glaciation.
Zurück zur Übersicht