Pleistocene river terraces - Qi1r, Qi2r, Qi3r - are capped by clay-rich, reddened soil horizons with obvious CaCO3 accumulation and situated above the landscape relative to the modern river.
From Cook and others, 2011, Mapping of River Alluvium Along the Verde River and Major Tributaries, Central Arizona.
https://library.azgs.arizona.edu/item/PPPP-1552427407753-684
Photographer: Joseph Cook
Photo Date: circa 2011