These were found in the Moab Utah area. They are small, fragile, and hard to photograph when Man is way ahead of me on our hikes (speed shooting from the hip, no time to set up a tripod, which I refuse to carry, frame quickly, zoom a bit, shoot, try another shot, run to catch up to Man on the trail).
There is a great article on the soil crusts at the Canyonlands National Park web site, which explains what it is, how fragile, how to protect.
My photos don't do justice, but here they are. The prickly pear are about 3 or 4 inches high, that gives some size reference.
I actually really love this one, showing the crust in the foreground and the fabulous red rock formations in the background.
Below, the best close up shot I could get without stepping on crust to get a photo of crust.
Who knew? Black, small, unassuming crusty stuff, that looks similar to tar, could be such a challenge to photograph and so interesting too. I so wanted to reach out and touch, but, I didn't. The phrase, "It's all in the details", keeps coming to mind. Slow down, look around, look for the minuscule, it can be downright fascinating.