Flume Gorge Rock Formation
The Flume Gorge rock formation is a natural occurance of solid granite at the base of Mount Liberty discovered in 1808.
The solid Conway granite rock formation at Flume Gorge is a natually occuring chasm that was discovered in 1808.
The explanation of how the gorge formed is that it is a fossilized remnant of a basalt dike or cast.
Magma flowed into a crack in the granite which then widened it to the point you see today.
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Eventually the basalt (or old magma) eroded faster than the granite could then leaving the crack as you see it today.
Some of the basalt is still visible in a cave at the head of the canyon.