What did we find out?

Sandstone comes from pebbles and sand that get "glued together" over time. Sandstone sure seems to vary a lot and the differences affected our biking. Porcupine Rim was crazy. There was a lot of loose gravel and large rocks along the trail. There were also a lot of jumps and broken rock. The sandstone seemed to be made from larger rocks and pebbles, which break easier and clutter up the trail. Slickrock's sandstone only had small sand grains, and a lot of bowl-shaped valleys. It was a smoother ride than Porcupine Rim, with very little debris. We figured the differences come from the way the two areas formed. Porcupine Rim's rock must have been put there by flowing water, maybe a river that dried up. Slickrock looks like a petrified sand dune, which tells us that wind must have brought all the sand here. We're going to bike some more and look for more clues to confirm our theories. more...