Sometimes the stones are small and gravelly. Sometimes they're mixed with broken branches. Sometimes they're almost square-cut and too heavy to move. On a hillside where I lived some years ago, the cliff face was clay, which oozed in rainy season; after the spring thaw, round rocks pushed their way through the clay and piled up at the bottom.
I stop often to poke around at the bottom of cliffs, cautiously, because the stones are usually unstable, and more overhead are just waiting to fall. Sometimes I bring home a stone or two in my pocket, only to abandon it later. A few end up in my garden.
I liked the pattern on these two rocks at the base of a cliff beside Buttle Lake.
The black stuff looks like tar; shiny, blue-black. But solid, welded to the rock. |
Another one. |
Scree is a collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces. (Wikipedia)
Wikipedia gives a list of processes that give rise to scree. Weathering, thermal and topographic stresses, biotic processes (burrowing, etc.). But they forgot this very common one; road building, blasting through rock to make a ledge. Unless that falls under biotic processes, actions by living creatures, in this case us and our earth-moving machines and dynamite.
Most of the scree at the side of the Buttle Lake road is man-made. Down on the shore, the stones are smaller, more uniform in texture and shape, a bit worn down; they've been there since before our time.
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