Geologic Map of Utah
Image courtesy Brigham Young University
Utah contains some of America's most spectacular geology. The western part of Utah is in the Basin and Range province. Due to plate movements on the far-off west coast during late Tertiary time, this part of the state and all of Nevada to its west have been stretched by some 50 percent. The upper crust split into strips, which tilted upward into ranges and downward into basins, while the hot rocks beneath rose up to elevate this region by nearly 2 kilometers. The ranges, shown in various colors for their rocks of many different ages, shed huge amounts of sediment into the basins, shown in white. Some basins contain salt flats, most notably the floor of former Lake Bonneville, now a world-famous test track for ultrafast automobiles. Widespread volcanism at this time left deposits of ash and lava, shown in pink or purple.
The southeastern part of the state is part of the Colorado Plateau, where the mostly flat-lying sedimentary rocks laid down in shallow Paleozoic and Mesozoic seas were slowly raised and gently folded. The plateaus, mesa, canyons, and arches of this region make it a world-class destination for geologists as well as wilderness lovers.
In the northeast, the Uinta Mountains expose Precambrian rocks, shown in dark brown. The Uinta range is part of the Rockies, but almost alone among American ranges, it runs east-west.
The screen-size version is 1200x1575 pixels (1 MB) and is fully legible, including the explanation of the rock units. The jumbo version is 1600x2100 pixels (1.1 MB) and preserves all the detail of the original scan.
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