The Pit at Pt Lobos, California by ahochstaedter

The Pit is a small cove nestled between Coal Chute Point and Granite Point. The Monterey Peninsula is visible in the background. Within the cove, Harbor Seals rest on algae-covered rocks at low tide, and giant Kelp is visible just below the water surface.

Two main rock types occur in this image: the Santa Lucia granodiorite and the Carmelo formation. The 100-million-year-old Santa Lucia granodiorite is the lighter colored and heavily fractured unit cropping out in the left portion of the image. It has very distinctive, large, blocky potassium feldspar grains up to 5 cm in length. The Carmelo formation is the buff colored conglomerate cropping out towards the right in this image. The Carmelo formation contains interbedded conglomerate, sandstone, and minor mudstone. Graded bedding observed in some of these outcrops as well as elsewhere on the peninsula lead to an interpretation of a high-energy submarine canyon depositional environment. In this image, the sharp depositional contacts between the Carmelo formation and the granite are at a high angle to bedding in the Carmelo. These contacts lead to an interpretation of deposition within a submarine canyon. The large granite block near the center of the image is either a large block of granite that tumbled into the submarine canyon, or a vertical pinnacle of granite that was later buried by coarse-grained channel floor material. In any case, contacts with the Carmelo formation are sharp and at a high angle to bedding, indicative of the sides of a submarine canyon or central pillar of granite.