Brief Geologic History of Monument Valley
Using all the observations, the most likely sequence of events
is as follows:
- The lower sandstone layer was deposited first.
- The environment changed and rivers deposited a number of mud
- Occasional floods deposited thin layers of sand with the mud.
- The environment changed again, and sand dunes covered the
region, depositing the cliff-forming sandstone.
- Evidence from adjacent areas indicates that other rock layers
were deposited on top, and the weight of these helped turn the
sand and mud into solid rock.
- The region was uplifted and eroded by streams, with erosion
removing nearly all of the sandstone and mudrock layers, except
that preserved in the buttes.
- The landscape continues to change slowly, with large blocks
falling off the cliff and rock varnish developing on those surfaces
that are stable for thousands of years.
- Space aliens, if they visited, left no record.
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