A 900 ky record of strath terrace formation during glacial-interglacial transitions in northwest China

The timing of the development of strath terraces with respect to climatic variability remains equivocal. Previous studies attribute strath-terrace formation to glacial or interglacial climates or to variations in sediment and water fluxes that cause lateral erosion followed by vertical incision. A chronology of strath-terrace formation spanning similar to900 k.y. has been generated on the basis of loess-paleosol couplets and paleomagnetic, thermoluminescence, and radiocarbon dating of strath terraces in the Qilian Shan of northeastern Tibet. Repetitive stratigraphic and geomorphic patterns on each terrace indicate that they formed during glacial-interglacial transitions. Long-term bedrock incision rates and inferred rock uplift rates appear steady and unrelated to strath formation over the past 900 k.y.