This story is part of our summer series "Beachcombing," in which KPCC reporters will explore the ecology, economy and culture of Southern California's beaches and coast. Let us know what you think in the comments below or on KPCC's Facebook page.
If you’ve walked on a southern California beach, you’ve made direct contact with the region’s ancient geology.
“I suppose I take it for granted,” says UCLA geology professor Tony Orme. He’s spent 40 years studying the way this coast has been shaped. Over millennia, sediment on beaches came down to the coast through mountain watersheds, and eroded off of coastal cliffs.
The sand on beaches between Point Dume and Redondo Beach comes in part from the San Gabriel Mountains: silvery mica, milky quartz, whitish-gray granite with flecks.
KPCC's Molly Peterson reports on what SoCal sand is made of.