(Late Neogene and Quaternary)
~10 million to 100 thousand years ago
While the Colorado Plateau is dominated by sedimentary rocks, Zion's proximity to the Basin and Range Province has caused it to be influenced by the relatively recent volcanism which rings the plateau. This volcanism takes the form of cinder cone volcanoes and basalt flows found throughout the Zion region.
The oldest flow found in Zion is ~1.4 million years old (significantly younger than any of the sedimentary layers), and the youngest-- the Crater Hill lava flow and cinder cone –is estimated to be just 100,000 years old –very young in geologic time!
These volcanic features can be seen along State Route 9 near the town of Virgin, and at several places along the Kolob-Terrace Road, including Lava Point.
Columnar joints, like these in the Crater Hill basalt flow, form as the lava cools and contracts, and are oriented perpendicular to the surface of the flow.
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Last updated: June 13, 2015