|Paleobotanist Howard Schorn documents with a digital camera several fossil leaves he's just dug up from Lygodium Gulch, Middle Eocene Ione Formation, Ione Basin, California. At this point, we've yet to call in the backhoe operator to help us more efficiently expose the supremely fossiliferous horizon here. Image taken on July 28, 2002.|
Paleobotanist Howard Schorn gets down to business at famous Lygodium Gulch, in the Middle Eocene Ione Formation, Ione Basin, California. This was late morning on July 28, 2002, during our first day of digging at the fossil quarry. Already the sun was blazing, auguring extremes of 100-plus temperatures for the western foothills of the Sierra Nevada. But, we were game. We were working hard, plunging mining-style picks, geology rock hammers and shovels into the Ione strata there to expose to their first light of day, in some 45 million years, the beautiful Middle Eocene leaf fossils. The specimens here are stained a striking reddish-brown on a brilliant white matrix of shale that contains a high percentage of biotite and feldspar. Lydodium Gulch is situated high in the lower member of the Ione Formation, and the rocks carry greater quantities of feldspar than the primarily quartz-rich and kaolinite clay-saturated strata lower in the section. The presence of feldspar and biotite in the Lygodium Gulch section denotes less humid paleoconditions during deposition of the fossiliferous layer. Image taken on July 28, 2002.
After our first day of heavy-duty, brute-force digging by sheer brawn, Howard made a command decision--he'd hire a local backhoe operator to entrench Lygodium Gulch, exposing with efficient ease huge blocks of leaf-bearing shales for us to split with greater effectiveness. We'd found many quality leaf specimens that day...but, the digging was going far slower than we'd expected.
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.