Friday, January 1, 2010

The Other California: The Prairies of the Past

Photo from the San Joaquin Valley Paleontology Foundation

A colleague of mine in an earlier phase of my life at Santa Barbara City College was fond of saying to field trippers that "I wouldn't take you JUST anywhere!" And a great Peanuts cartoon talked about a field trip the kids went on, and how they went and saw...a field. And that's what we have today: not just anyplace, and it is ... a field. And not just a field, it's a real dump. Well, ok, more like a municipal solid waste landfill.

My home, the Great Valley geomorphic province, is, well, a field. A really BIG field, about 400 miles long, and roughly 50 miles wide. It ranges from sea level to at most a few hundred feet above sea level, and it is exceedingly flat. I wasn't too thrilled when I first moved here; we geologists like to have some kind of topography in sight. Little remains of the original landscape, maybe 5%; most has been altered by agriculture and urban development. I discussed some of the remaining grasslands in the original post of this series.

When Europeans first came upon the valley in the 1700's, they found a prairie/ savannah environment with tule elk, deer, pronghorn antelopes, wolves, coyotes, and grizzly bears. It could actually be dangerous to be out and about without weaponry. Today the big danger is to avoid getting run over by a tractor/combine on the isolated country roads.

I always tell my students that the geological story of your home is fascinating, no matter where you live. I was challenged to make our Great Valley interesting, but just like people, the most interesting aspect is inside, beneath the surface.

In 1993, Madera county was excavating a landfill at Fairmead (about 20 miles northwest of Madera) when the big shovels uncovered bone fragments at a depth of 40 or so feet beneath the surface. Because of state regulations, a paleontologist was called in, and an intriguing story unfolded. During the ice ages around 500,000-700,000 years ago, this landscape was cooler, with a more humid climate, and shallow rivers coursed across the grasslands. And a host of wonderful and strange animals lived out their lives here. In the last 17 years, some 14,000 bones, representing 37 species have been found at the site. Numerous horse and camel species, pronghorn, giant ground sloths (three species),and Columbian mammoths are included among the plant-eaters. The carnivores include coyotes, wolves, sabertooth cats, and the hulking short-faced bear. A wide variety of smaller rodents, fish, amphibians, and reptiles rounded out the ecosystem. It turned out to be the one of the most important Irvingtonian aged fossil assemblages to be found anywhere in California.

So what is a dump operator to do? Apparently, the right thing! A foundation has been established, the San Joaquin Valley Paleontology Foundation, and construction has begun on a Fossil Discovery Center at the landfill site that will serve as an education/research facility housing many of the specimens (most are currently at Berkeley and CSU Fresno). Science education opportunities are sorely lacking in the Great Valley, and this center will be a wonderful addition to the few resources that are currently available.

So, the next time you happen to pass through Madera or Fresno (presumably on your way to someplace else), check on the progress of the Fairmead Fossil Discovery Center. It's a unique part of the geological landscape of California.

Note: I haven't been there yet. All the photos are from the website for the San Joaquin Valley Paleontology Foundation and other online sources (credited below).

Camel bones at the Fairmead Landfill, photo from the California Integrated Waste Management Board

Painting by David Douglas for the San Joaquin Valley Paleontology Foundation

Geology and stratigraphy information about the site:

Preliminary 1996 report on the site

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