Falls Trail Stop 11

tan rock borders darker rock
Basalt tuff boundary marks old Rio Grande channel

Photo by Sally King

Stop 11: If you look at the northeast wall of the canyon, you can see a marked boundary between basalt and tuff. This demarcation represents one side of an old Rio Grande waterway. Before the eruption of the Jemez Volcano this is where the big river flowed. Its channel was changed and pushed southward by the new deposition of ash. Look a bit further downstream and you can see another basalt-tuff boundary outlining the far wall of the abandoned Rio Grande channel.

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Last updated: January 16, 2022

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