Late Cenozoic lava dams in the western Grand Canyon

"The Late Cenozoic history of the western Grand Canyon is one of profound and rapid transformation. The constantly changing morphology and dynamics of the canyon during this period have been recorded in spectacular geologic features, such as frozen lava cascades and lava dams, as well as volcanic cones, necks, and dikes. All of these unique features, which make the western part of the Grand Canyon strikingly different from other parts, resulted from the interaction of basaltic lava flows and vigorous erosion by the Colorado River." "The volcanic phenomena in the Grand Canyon were created by eruptions of basaltic lava in the southernmost part of the Uinkaret volcanic field. Some lava flows were extruded on the Uinkaret Plateau and cascaded over the outer rim of the Grand Canyon into Toroweap Valley and Whitmore Wash, while others were extruded within the Grand Canyon itself and partly covered the Esplanade Platform. The remaining flows cascaded over the rim of the canyon's inner gorge. Red molten rock cascading into the canyon and forming lava dams must have presented a spectacular scene, the likes of which have never been viewed by human beings." "Even more spectacular is how quick