Fossil Leaf From The Ione Formation

Western Foothills Of The Sierra Nevada, California

Middle Eocene, 45 Million Years Old

Here is an undescribed fossil leaf on a chunk of feldspar-rich shale from the Middle Eocene Ione Formation, western foothills of the Sierra Nevada, California. Midrib (primary vein), secondary veins, part of the petiole (stem) and the margin have all been preserved intact; venation is pinnate, the margin entire--that is the edge of the leaf is smooth and non-serrated; reddish -brown coloration is caused by iron oxide residues in the rocks, which formed during Eocene times under semi-tropical, humid, chemically reducing paleoconditions. Paleobotanists should be able to identify this specimen, eventually. 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.

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