Bouse herringbone pattern (IMAGE) University of Oregon Caption The herringbone pattern seen in cross-bedded carbonate sands in the Bouse Formation, University of Oregon researchers conclude, is the result of the classic back-and-forth movement of water unique to ocean tidal systems. UO researchers have published two new papers that solidify their belief that the lower Colorado River valley, now a desert region, was covered by marine tidal basins during a hot, humid climate more than 5 million years ago. 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.