The scientists hypothesize that the crumbly rock also started clean and gray, but underwent chemical transformations, perhaps from water.

They reached a level height made [107] up of crumbly rocks.

Anyone can mark a crumbly rock, sure, or tell a tree to write a sigil with its branches.

With maddening slowness, he clambered along the narrow canyon that separated the back of the building on one side from crumbly rock on the other.

Soft, crumbly rock shifted and broke under the impact of their steel-shod feet.

Allegedly there are 250 steps carved into the crumbly rock but I think they missed a few and I struggle to reach the top.

The surface was irregular enough to allow climbing, but the crumbly volcanic rock made it necessary to test each hold before transferring his weight.

Above her bed, however, where the walls meet the ceiling, are gouges exposing crumbly gray rock and rusty wire mesh.

Since slippery and crumbly rock makes climbing somewhat difficult here, High Rocks is notable mostly to local climbers.

Late in the day on their summit push, the two Americans climbed a stratum of steep, crumbly rock- the infamous Yellow Band.