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Fossils from a lost sea Mail Tribune / Bob Pennell Ed Vaughan found what appear to be 100-million-year-old fossils on his South Stage Road farm. A Jacksonville-area man digging an irrigation canal on his land finds remains from 100 million years ago amid sandstone rocks By BILL VARBLE Mail Tribune Ed Vaughan turned over some sandstone rocks near Jacksonville and found the fossilized remains of sea creatures from 100 million years ago. Vaughan, who lives near Jacksonville, was digging an irrigation system along the edge of a section of his pear orchard eight years ago when he found the remains of animals that made their home there when the area was at the bottom of an ancient sea. Some look like snails, some like spiral-shaped worms and some like ridged clams. Vaughan has kept some of the smaller samples in a coffee can in his shop for the past eight years. "We're probably driving over the top of a bunch of them now," he says as his farm truck bounces through the fields north of Jacksonville. As storm clouds swirl around Roxy Ann Peak and meadowlarks sing, Vaughan turns over several chunks of rock near a diversion ditch in the field. He uncovers two fat black widow spiders but no fossils. Later he shows off fossils embedded in basketball-sized sandstone rocks. Geologists say the sediment containing the fossils is a mudstone mass known as the Hornbrook Formation. Underlying much of the Bear Creek Valley, it dates from a huge inflow of ocean water into the area 100 million years ago. The clam-like fossil is a member of the Pterotrigonia genus, says Southern Oregon University geology Professor Monty Elliott. "It's an index fossil," Elliott says, "an unusual fossil that tells the age of the rock. It's the equivalent of the modern cockle. There are three species." Elliott says the worm-like critters could be species of either snails or ammonites, which have been extinct for about 65 million years. The snail-like fossils could belong to any of a number of species. It's not uncommon to find such things in the 4,000-foot thick Hornbrook Formation, Elliott says. "Especially the southwest margin of the valley, from Jacksonville toward Dark Hollow and behind Talent and Ashland." Elliott says the creatures were near-shore species, or high-energy environment mollusks with thick shells. They made their living in a turbulent zone characterized by wave action, currents and storm activity. Fossil clams appear often in Klamath Mountain rocks. Frank Callahan, president of the Roxy Ann Gem and Mineral Society, last year found a 90-million-year-old ammonite fossil in a piece of shale near Dark Hollow Road. The philosopher Aristotle taught that living organisms could arise by spontaneous generation from mud; in his view, fossils were animals-in-the-making that failed to complete the process. But scientists have long known that fossils are formed when groundwater permeates bones, teeth or shells, and the minerals in the water slowly replace the original material and leave it as durable as stone. Shells, bones and teeth, with their high calcium content, have a better chance of preservation than other organic material, although soft-bodied marine worms are sometimes preserved in such sites as the Burgess Shale of British Columbia. Vaughan says some of his 150 acres have deep soil and few if any rocks, while other areas are too rocky to plow. "My father-in-law calls one spot Rocky Acres," he says. The Hornbrook Formation is sometimes exposed at or near ground level. Its rocks sometimes look like flagstones but shatter easily. Elliott says that people who find fossils and want to know more about them can bring them to the geology department at SOU. Geologists there can usually tell whether fossils are from near the shore or from a deeper marine environment. "That's one of our functions," he says. "We look at fossils, suspected meteorites, all kinds of stuff." Reach reporter Bill Varble at 776-4478 or e-mail [email protected] Mail Tribune Home | Ottaway Newspapers, Inc. | Dow Jones & Co., Inc. | Privacy | Contact Us Copyright � 2001 Mail Tribune, Inc.