Developing cave

Yachats, Oregon. The light gray rock is old mudstone, the reddish-black rock is overlying basalt lava. The little knob of light gray rock in the red-black lava? Probably stirred up and mixed into the lava as it flowed over. This is called "breccia." The cave is probably developing along a seam of loosely congealed breccia. Cool? Cool.

Done