An undescribed fossil leaf preserved on a chunk of feldspar-rich shale from the Middle Eocene Ione Formation. Note the well-preserved midrib (primary vein) , secondary veins and the margin; venation is pinnate, the leaf margin entire--that is, the edge of the fossil is smooth and non-serrated. Paleobotanists should be able to identify this specimen, eventually. Reddish-brown coloration is due to the presence of the mineral iron oxide, which formed during Eocene times in a semi-tropical, humid, chemically reducing paleoenvironment. The roughly 45 million-year-old specimen came from an extraordinarily rich locality on private property in Amador County--a specific site currently under formal paleobotanical study by Dr. Jack A. Wolfe (retired member of the United States Geological Survey) and Howard E. Schorn (retired Collections Manager of Fossil Plants at the University California Museum of Paleontology in Berkeley), among others, who hope to use the fossils to help approximate the paleoelevation of the ancestral Sierra Nevada region during the geologic past.
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.