Monday, March 14, 2011

A shorter hike

Sunday was another beautiful day so I had to get out and do something. My ankles were still a little achy from Saturday's hike. I didn't want to hike a long way. I decided to climb something.

My original plan was to climb this, maybe from this side (looks doable from here), maybe from the other side.

As I got closer to what I planned to climb, it looked less climbable. Maybe I could climb it from the other side. When I got over there, that side looked pretty steep, too. Well, I didn't go out there to struggle. I kept walking down the wash, looking for something else to climb. I got almost to the rock wall I climbed about a year ago before I found a gentle slope and started up. I didn't care if I got to the top of anything. I just wanted to climb for a while.

I'm going in that direction.

If you look closely at that last picture, you'll see that the rocks at the top of the cliff are black. Everything below them is very light colored rock. Everything except for the rocks that had fallen from up there, that is. Any spot that was level enough that pebbles up to refrigerator size boulders would stop rolling was littered with black rocks. I know that the dark rocks weren't released from the light rock by weathering because there are no dark rocks embedded in the light rock. So why all this discussion about the black rocks? Because you can tell that some of them have been sitting in the same place for a very long time. I don't know how fast that light rock erodes in the desert, but I would bet that some of those rocks have been sitting where they are for at least hundreds of years.

A prime example of a rock that has been in one place so long that the rock under it has eroded away to just a small pedestal.

I don't know what eroded the light rock away, either. You might think that rain falling could easily leave the pedestal. If that was the only cause of erosion, then those rocks have probably been sitting there for thousands of years.

I got high enough to have a view of the Superstition Mountains. I climbed around on that rock in the foreground when I hiked up to Richard's Arch a few weeks ago.

Much of the light rock is covered with thin soil and moss. The moss could grow right up to the black rocks but of course could not grow under them. I believe the moss helps break down the light rock into soil. As it "ate" away at the light rock at the edges of black rocks, it was able to undercut the black rocks and eventually leave the black rock on a pedestal. There is no moss around the black rocks in my pictures, though. Well, there are large areas where the rock is bare. I think cattle could have tromped around up there (there is a stock tank nearby, and barbed wire fence) and their weight would have broken up the fragile moss and soil, making it susceptible to erosion by rain. The pedestals are created by plants converting the light rock to soil and revealed by soil erosion caused by cattle brought here by Europeans. Couldn't deer have damaged the soil? Well, I rarely see deer footprints anywhere but in sandy washes (they are lighter) and I don't think deer are as concentrated as cattle tend to be. The number of deer would have been kept in check by mountain lions and wolves, but those predators were wiped out to protect cattle. I may be full of beans, but I think it's an interesting idea.

Down there is the rock wall I climbed on a very warm day last summer.

Click below to see all of the pictures.


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