Geological Discontinuity
I took this image because of the impressive geology featured. The rock layers plunging from the middle of the image off to the lower right are relatively finely layered orange and darker sedimentary material. But below them is a much more monolithic grey mass.
The materials suggest to me that two different methods of deposition occurred in the past, although I'm not expert enough to explain the lower one (oolitic limestone perhaps?). The finer layers exhibiting bedding planes would suggest sandstone to me.
Note that the monolithic grey material breaks up quite readily when not covered. On the mid-left of the image, the finer layers have gone, and the underlying grey rock has broken up down to the level I'm standing on, apparently as a resulting of rapid vertical cracking (some visible in the interface between the left and right).
These rocks are in the north wall of the Grand Wash, one of two deep but easily-accessed canyons along the scenic drive at the centre of Capitol Reef National Park in Utah.
Grand Wash offers a pleasant, safe introduction to narrow canyon hiking, although even here there are prominent warnings of the dangers of flash floods.
The wash cuts right through the reef and features sheer cliffs of Wingate and Navajo sandstone up to 150m high (in the background above), with many colourful strata and eroded rock formations.
The exact location along Grand Wash Road is arbitrary as I can't remember exactly. In terms of scale, the top of the bedding planes is about 4m above the floor in the foreground. The image is scanned from a negative.
Geological Discontinuity
I took this image because of the impressive geology featured. The rock layers plunging from the middle of the image off to the lower right are relatively finely layered orange and darker sedimentary material. But below them is a much more monolithic grey mass.
The materials suggest to me that two different methods of deposition occurred in the past, although I'm not expert enough to explain the lower one (oolitic limestone perhaps?). The finer layers exhibiting bedding planes would suggest sandstone to me.
Note that the monolithic grey material breaks up quite readily when not covered. On the mid-left of the image, the finer layers have gone, and the underlying grey rock has broken up down to the level I'm standing on, apparently as a resulting of rapid vertical cracking (some visible in the interface between the left and right).
These rocks are in the north wall of the Grand Wash, one of two deep but easily-accessed canyons along the scenic drive at the centre of Capitol Reef National Park in Utah.
Grand Wash offers a pleasant, safe introduction to narrow canyon hiking, although even here there are prominent warnings of the dangers of flash floods.
The wash cuts right through the reef and features sheer cliffs of Wingate and Navajo sandstone up to 150m high (in the background above), with many colourful strata and eroded rock formations.
The exact location along Grand Wash Road is arbitrary as I can't remember exactly. In terms of scale, the top of the bedding planes is about 4m above the floor in the foreground. The image is scanned from a negative.