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| Mosaic Canyon |
Mosaic Canyon interests me due to the diversity of rock within one area. In the photo above we have fairly well-sorted sediment on the floor, then breccia made up of darker ground mass and containing large, angular fragments that are not well-sorted. Upon closer inspection beneath the breccia, one can see larger rock fragments that is consistent in size and shape among the other small accumulation of similar grains beside it. It's also asymmetrical. Meaning one doesn't see the same larger fragments on the left side left side of the canyon.
The bend in the center suggests that the floods that come through here must first run into the right side from a bend behind the photographer, and bending in the opposite direction than the bend ahead. So the canyon in this location forms an S curve. This is important because the eroded edge on the right wall in the center probably impedes flow, causing eddies to form and therefore causing larger sediment to lose sufficient velocity so that it accumulates on the right.
Some questions I have are:
Is the "finer" floor sediment also the same as the ground mass in the breccia? Is it just broken down and better sorted? Perhaps older, and dislodged upstream and transported here eventually?
The very large clast is interesting. It looks more rounded than the rest of the clasts. This suggests it traveled much further. Given its size, it must've also been part of a flood with immense velocity.
What are the age differences of the rocks? A geological map will be useful here. It might be interesting to ascertain the probable extent of travel by calculating the kind of velocities that would be required to transport the larger clasts to this location from upstream and from various distances. This would give us a realistic upper flow velocity bound for floods, which could help us narrow our search in the geologic map by confining it to a certain distance from this location.
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