Note 26 — The Age of Reptiles

Paul L. Williams, U.S. Geological Survey, told me in November 1978 that he observed H₂S-bearing spring water leaching the color from both the Entrada and Wingate Sandstones above Tabeguache Creek some 8 or 10 miles north of Nucla, Colo., and from the Wingate alone along Onion Creek in eastern Utah.