Bouse Formation riverbed (IMAGE) University of Oregon Caption Kevin Gardner, an earth sciences doctoral student at the University of Oregon, stands in a riverbed in the Palo Verde Mountains, about nine miles southeast of Palo Verde, California. Behind him is Meaghan Emery-Wetherell, who earned a doctorate from the UO in 2016. The riverbed, within the Bouse Formation, contains white tidal flat carbonates that overlain by red silts and muds, evidence that points to a seawater past. Credit Photo by Rebecca Dorsey Usage Restrictions use credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.