INVESTIGATING LANDSCAPE ANTIQUITY AND CENOZOIC DRAINAGE DEVELOPMENT OF SOUTHERN YUKON (CANADA), THROUGH RESTORATION MODELING OF THE CORDILLERAN-SCALE TINTINA FAULT
Topographic restoration and hydrological models show that the drainage of the Yukon River northwestward into Alaska via the ancestral Kwikhpak River was only possible at restored displacements of up to ~50-55 km on the Tintina Fault. We interpret the published drainage reversals convincingly attributed to the effects of Pliocene glaciation as an overprint on earlier Yukon River reversals or diversions attributed to tectonic displacements along the Tintina Fault. At restored fault displacements of between 230 and 430 km, our models illustrate that paleo Yukon River drainage conceivably may have flowed eastward into the Atlantic Ocean via an ancestral Liard River which was a tributary of the paleo Bell River system.
The revised drainage evolution, if correct, requires wide-reaching reconsideration of surficial geology deposits, the flow direction and channel geometries of the region’s ancient rivers, and importantly, exploration strategies of placer gold deposits.