alluvial

The forested ridges catch rain, and water percolates into the canyon’s alluvial soil, where the trees’ roots tap into shallow groundwater.

From Zabriskie Point, visitors can survey a wonderland of rock formations and alluvial flow, and it’s just about impossible to tell what happened last week from what happened last century.

“The weaker alluvial sediments can amplify shaking, and mountains are vulnerable to landsliding, including along the roads that lead to mountain villages.”

It’s a desolate alluvial fan on the southern flanks of the Cady Mountains, where sparkling calcite crystals and pieces of quartz, jasper and agate are continually carried down the slopes by thunderstorms and flash floods.

Prospectors call it “flood gold” — fine-sized flakes carried by alluvial waters and then deposited as flow recedes.