One of the most spectacular features in the St. George basin is the series of late Cenozoic basaltic flows that were extruded near the base of the Pine Valley Mountains and flowed southward into the ancestral drainage of the Virgin River. These flows are now preserved as south-trending inverted valleys up to 400 ft(120 m) high which stand in bold contrast to the brilliant red and white east-west trending cliffs and slopes formed on the older Mesozoic rocks. The arid climate and sparse vegetation result in excellent exposures of the striking red, white, and black rocks of Utah’s “color country” and provide scenic emphasis for what is one of the most impressive examples of topographic inversion in North America.
Figures & Tables
Rocky Mountain Section of the Geological Society of America
One of six volumes generated by each GSA section for the Decade of North American Geology (DNAG) project, this Centennial Field Guide contains descriptions of 100 sites or site clusters representing outstanding geologic locations in northern Arizona, Colorado, Idaho, Montana, North Dakota, New Mexico, South Dakota, Utah, Wyoming, and Alberta.