Certainly, this is one the richest and potentially most productive fossil leaf-bearing zones in the Middle Eocene Ione Formation of the Ione Basin. The horizon is marked by the red backpack at lower middle. The protruding brownish sandstone ledge at lower right contains innumerable fossil plants, layered one atop the other as if they had fallen like leaf litter on the ancient forest floor. Their preservation here, though, is likely the result of deposition in a floodplain setting---leaves attached to plants growing along the estuaries and floodplains of subtropical Ione Formation times were probably torn free and transported by agitated waters of an Eocene storm, then winnowed out in quiet waters, where they accumulated one atop another, preserved in time for some 45 million years. I discovered this locality during a hike amidst the Ione Formation of the Ione Basin in the mid 1990s. Please note: All fossil localities in the Ione Formation of Amador County, California, presently occur on private property; explicit permission from the land owners must be secured before collecting fossils there. |