Sunday, December 4, 2011
Spending a Day in the Earth's Mantle: Exploring Del Puerto Canyon in California's Coast Ranges
a bit of a ruckus about our state rock last year in the media and legislature).
But not all of the rock is turned to serpentine. In the upper reaches of the canyon, a mass of rock several miles across was pushed to the surface without quite the degree of metamorphic change, and as such it preserves some of the original minerals and textures of the mantle rock. We found some very nice samples of the chromite ore (below), a heavy metallic mineral that occurs in small grains within the ultramafic rocks.