There was a reported find of a mammoth tooth in the tide waters of Tomales Bay, part of our ‘backyard.’ The relic is fragile and will be studied at length. That this extinct animal flopped over dead near the bay could be a result of pollution, the area is rift with cows. Some science exists that proves cows are an important factor in ground and water pollution and expel vast amounts of methane gas. Possibly their three-stomach digestive process is the culprit behind the flatulent cows. More likely the poor beast ate some bad clams.
In the local fossil record, there is evidence that the ocean waters have risen and fallen consistently over cyclical periods. Not just woolly mammoth evidence right here in Sonoma County but fossilized seashells in the low hills around the county. This suggests that indigenous people ate a lot of seafood or the cyclical nature of the earth is just that, ‘cyclical.’ In reading the opinions of scientists on the varying nature of seawater levels a picture emerges of massive changes in seawater levels. There is evidence of saltwater levels so high that you could dig clams in Cotati. Look at a map of the county and you will see that the middle is a wide, shallow bowl with low mountain ranges forming the sides of the bowl known as the Santa Rosa plains. The adobe mud we all know and love to hate, is itself a fossil record of a muddy sea floor.
A quick study of timeline charts of periods of glaciation (Google Image: Ice Age Cycles, to read the same charts) throws a monkey wrench into the mix. The charts are all over the map! If you look at just the period of human occupation of the Americas, the cycle is a bit less murky. It is a widely accepted theory that man came here only twelve thousand years ago during a mini-glacial period that froze so much water that a land bridge formed linking Siberia to the North American continent. In theory it was this land bridge that opened the western hemisphere to human occupation. If you focus on only the last twelve thousand years, the chart begins to come more into focus, sort of. Given the average temperature charts, the sea-level charts, the ice core records, and sea floor records reveal that the earth is a dynamic environment, constantly changing. So, the next time you find a seashell in your back yard it may not have been from the oyster feed two years ago but a true record of sea levels right where you stand.
In terms of geologic time humans are but a tiny layer in the four-billion-year years since the earth was formed. To get a closer look at geologic evidence take yourself to the Gem and Mineral Society annual show at the Veteran’s Building in Santa Rosa. The show opens at 10 a.m. both days and is stuffed with fossils, gems and displays. You may be able to purchase a fossil or two, petrified wood is always fun to hold in your hand, as is a dinosaur bone fossil or a real meteorite. The local Gold Bug Cub will host a free display of their favorite metal and will teach young ones how to pan for gold. There will also be activities for children, rock painting, jewelry making and prizes to be won, think shiny rocks. For more details go to their web site: http://www.srmgs.org on the right hand side of the page you will find clicks for show details, one of which is a ‘dollar off’ coupon. Alternatively, you can go to Facebook and search for SRMGS or, Santa Rosa Mineral and Gem Society, for details. Kids under twelve are free, adults are six without the coupon.
Bill Hanson is a Sonoma County native and a lifelong sportsman. He is the former president of the Sonoma County Mycological Association. Look for his column in The Community Voice each week.