Driving into the Earth’s Mantle

Del Puerto Canyon is a tectonic incision. As you drive eastward, you descend backward through deep time, crossing geologic layers normally buried miles below the surface. Here, ultramafic mantle rock, serpentinized and sculpted by pressure, emerges into daylight.
 

Faultlines and Subduction Histories

This region lies along the Tesla-Ortigalita Fault, part of a tangled web of fractures left behind by the Pacific Plate’s relentless push beneath North America. The rocks here were once oceanic crust—from far out at sea—pushed upward by ancient subduction zones. The Great Valley sequence and Franciscan Complex both testify to this upheaval.
 

Serpentine & Ultramafic Identity

Much of the canyon is carved into serpentinized peridotite, a metamorphic rock formed from Earth’s mantle. It’s rich in magnesium, poor in nutrients, and utterly inhospitable to most plant life. And yet, it gives rise to rare endemic species and some of the most distinct geology in California.
 

Magnesite Veins & Mining History
Within these serpentine exposures run veins of magnesite, a mineral once mined heavily in the early 20th century. Remnants of these mines can still be seen tucked into the canyon walls, part of California's forgotten mining frontier. These veins are part of the story, this place was formed under crushing heat and pressure.
 

Time Made Visible
Every exposed rock face here is a page from an ancient book. From seafloor sediment to mantle peridotite, Del Puerto Canyon makes visible the hidden bones of the Earth. This is experiencing geology on another level, you are seeing inner earths secrets pushed up past the surface.