Left to right: geologist Robinson Cecil and paleobotanist Howard Schorn study the fossil quarry at Lygodium Gulch in the Middle Eocene Ione Formation, Ione Basin, western foothills of the Sierra Nevada, Amador County, California. This is one of the most prolific and significant fossil leaf localities in all of California. It is a rare, essentially sea-level flora from the eastern shores of the great Eocene sea that covered California's Great Central Valley roughly 45 million years ago. The brilliant white, feldspar-rich shales here produce beautifully preserved fossil leaves stained an attractive reddish -brown (due to the mineral iron oxide). The Ione sediments accumulated here in estuaries and along the floodplains of a system of braided rivers under a chemically weathering climatic regime of high humdity, rainfall and heat--probably the climate was similar to that of southern Florida today. Image taken on June 3, 2003.
After our visit to Lygodium Gulch, Howard, Robinson and I returned to our motel rooms in Jackson for the evening. The next day, after breakfast at famous Loreta's restaurant in Ione, Howard and Robinson continued their tour of significant Eocene fossil plant localities higher up the slopes in the western foothills of the Sierra Nevada--specifically, at the long-abandoned open-pit hydraulic gold mines in California's northern Mother Lode country. Later that summer, Robinson returned to the northern Mother Lode to measure several important leaf-bearing sections in the Eocene auriferous gravels of what geologists call the ancestral Yuba River system.
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.