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Mendocino Geology for $1

You never know what you’ll turn up at a book sale. One man’s trash is another man’s treasure. While working on the Mendocino County history I’m writing I was thrilled to pick up “Mineral Commodities of California” (1957) for $1. In it were 736 slightly musty pages of geology and geography and references to Mendocino County.

Even with college classes in geology and geography in my past I wanted interesting LOCAL facts for my book. I discovered there is asbestos within the serpentine rock in the county. Graphite was mined 15 miles east of Point Arena. Chromite was mined near Leggett. On Salt Creek near Dos Rios was a coal vein mined for decades. Yorkville had a copper mine and the miners named their cluster of houses Little Penny.

Ever heard of Leech Lake, northeast of Covelo? There was a photograph in the book of jade mining there in the 1950s. If the claim is still there it is behind the locked gates of the Middle Eel-Yolla Bolly Wilderness area now.

While our geology in the county is not real exciting (lots of squished crumbled Franciscan formation) there are several guidebooks that can take rock lovers to interesting places for exploration.

A new one I really enjoy is “Shaping the Sonoma-Mendocino Coast: Exploring the coastal geology of Northern California” by Thomas Cochrane down at the Sea Ranch. It includes an 85 mile road log of Highway One to take you on a self guided geologic tour.

Places I describe in my new book, like Bowling Ball Beach down near Schooner Gulch, get detailed descriptions in this book along with information on the Devil’s Punchbowl and sea caves and blow holes near Point Arena.

If you enjoy poking around on public lands looking at rocks, traditional guides include “Gem Trails of Northern California,”

“Rocks and Minerals of California,” and “Rockhounding California.” The nice thing about these guides is that you can buy them used. Rockhounding locations never change. The access to the site may change but rock formations stay put.

One of my favorite guides is a 1974 copy of “California Gem Trails” by Darold Henry. Someday I’m going to go look for the jade family rocks described within on Tomki Creek and near Hearst and the North Fork of the Eel River. From my new old 1957 book I also want to try and find crocodolite, just because it has such a cool name. It’s a fibrous blue form of asbestos.

If readers like knowing more about local rocks and especially jade we have our own best living breathing source of information in Big Sam Gitchell at the Rock Stop on Highway 128 at Floodgate. Catch him on weekends and ask him to show you River Blossom Jade from a claim he has. That man is a walking encyclopedia of local geology.

The best places to find the guidebooks above are local independent bookstores and on-line for out of print titles.

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