The Story in the Rocks - Southwestern U.S.

This is Quil Creek Reservoir, east of the town of Hurricane, Utah. We are looking west Note the exposed strata to the left and the three buttes in the distance. Zoom in for better detail. Closer to the buttes we can see that they are uplifted on the side facing us and the flat surface on the top now tilts back away from us. There is a long line of uplifted blocks following the south side of the fault visible here. The outcroppings on the right form an uplifted ridge on the north side of the fault. I do not know what kinds of forces are buckling the surface along the fault. Are the two sides pushing against each other, or sliding along each other, or is something more complicated going on here?I am assuming that this is the same Hurricane fault that crosses the Grand Canyon.I have more shots from different positions including the back sides of the buttes.I think it is interesting that it looks like the fault runs right through the middle of the reservoir and that houses and the town of Hurricane are right on top of the fault and around the buttes.Edited by Tanypteryx, : grammerEdited by Admin, : Narrow image width.

I am not sure what you mean, but in edge's shot you can see a horizontal band and in many other deposits, I have seen clear layering bands. I do not know what the layering represents as far as the deposition event(s). Sorry if I implied I did.

In the bottom picture above is the ash the white slab like pieces at the bottom of the picture?

No. Those are sandstone or limestone that were hauled from somewhere else. I think the light colored material that shows in the outcropping on the right is ash.ABE: the light colored material in the center of the top photo looks like an ash deposit, also.Edited by Tanypteryx, : No reason given.

Because there are sandstones and mudstones interbedded with the ash flows. You can see the layering with more fluvial sediments in this picture. The reddish beds are more oxidized than the green-gray reduced beds. The tan beds are more resistant sandstone. I've also seen burnt coal beds mixed in with the ash. Looking for a picture.

Coalmine Canyon east of Tuba City has some layers like that, I think

So are you saying that in the pinnacle the topmost tan material is sandstone?Is the greenish part below that volcanic ash?What is the tan material at the bottom?

Yes, that layer is more resistant to erosion. Yes, and there are several layers of it. It is another layer of sandstone.ETA: By the way, if you google 'volcanic ash', you can get a lot of interesting photographs including fossils. Edited by edge, : No reason given.

How do you know there are several layers of it?

Contrasting colors and textures, coal seams, etc.Maybe pictures don't do it justice...

You've mentioned coal seams several times. How would a coal seam get formed?

In between eruptions, in a swamp-type of environment. Remember there are sandstone and shale interbedded with the ash as well. Some of the sand is pretty clearly fluvial and it's only a short step from there to a swamp or bog.

Swamps and bogs are one thing, mud stone and shale another, but how can actual coal be explained?

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Swamps and bogs are one thing, mud stone and shale another, but how can actual coal be explained?

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Are you saying that river sediments, sands and muds are not found with coal beds?I suppose there are some alternate ideas out there ...Here is a link to a review on how coal forms.Page not found, Kentucky Geological Survey, University of KentuckyAnd here is a picture of fluviatile sediments associated with coal in a New Mexico coal mine. Coal occurs at the bottom of the mine, with sandstone and mudstone layers above it. You can see a sandstone channel at the top of the highwall on the left edge of the image.Now, just imagine this sequence being deposited during a volcanic episode of rather large proportion, derived from one or more of the larger volcanic fields in the region.Perhaps I'm not explaining very well here, but I know that as we drilled for deep oil fields in the region, we encountered a lot of coal on the way down through the clay beds that you've seen in the these photos. I've also seen layers of 'clinker', the term for baked clay related to coal seam fires, interbedded with the ash; certainly ancient in timing.

So you are saying that there are actual layers of coal between layers of volcanic ash, correct?Edited by jar, : No reason given.