Warning: That Oregon coast trail is covered in loose shale

Last weekend, I was hiking along the Oregon coast and almost fell on loose shale. It got me thinking about how the ocean wears down the rock over years. Why do some parts of the coast have more of this loose stuff than others?

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3 Comments

danieltaylor7mo ago

Near Heceta Head, the shale is really loose because of constant wave action. The ocean hits some cliffs harder due to how the coast curves. Softer rock types break down quicker into that slippery gravel. Areas with more rain and freeze-thaw cycles also crumble faster. Over time, these spots just have more loose stuff piled up. It's all about how exposed the rock is to weather and water.

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jessetorres7mo ago

I mean, danieltaylor's point about wave action is solid, but it got me thinking. Is it just about how hard the waves hit, or does the angle of the cliff face play a bigger role? Like, if a cliff is steeper, does it shed shale differently? Idk, maybe it's just me, but I've seen spots where the trail cuts close to the edge and the loose stuff seems way worse. Are there any studies on how trail placement affects how fast the rock wears away?

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sullivan.margaret7mo ago

Devil's Slide in California has this one spot where the trail hugs the cliff edge. I'm so clumsy I probably kicked loose enough shale to change the erosion rate myself. Steeper angles do shed rock faster, especially when trails cut close and disturb the slope. A study from the University of Oregon found trails within three feet of the edge doubled the wear on some shale layers.

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