Most of the La Jolla Group stratigraphy was deposited during the Eocene when sea level was higher than its present-day elevation. Eocene aged formations of the La Jolla Group include the Ardath Shale, Delmar Formation or Delmar Sand, Friars Formation, Mount Soledad Formation, Scripps Formation, and Torrey Sandstone (alphabetical order).[2] There are only abundant fossils found in some sections of the Del Mar Formation, mostly bivalve shells.