When it comes to exploring Oakland’s rocks, I’m pretty self-sufficient, once I’ve consulted a map. I don’t mind a climb or a scramble, and I can find little geeky things that interest me pretty much everywhere. But for most people, rocks are unfamiliar things that don’t have obvious messages. Maybe those people are more comfortable at home in familiar surroundings. Even a nearby place like Round Top, an everyday sight, seems better admired at a distance.
People need other people to show them geology. Here’s a new way to make that happen. EarthCaches are a kind of geocache that don’t require you to find a hidden box and trade a trinket; instead, they’re places to stand, specified by a precise GPS setting, where you can read a prepared lesson about the geology of that spot. Learn more about them at earthcache.org.
There are more than ten thousand EarthCaches around the world, each one vetted by geologists through the Geological Society of America. As of today, there are seven in and around Oakland:
Orinda Formation on Skyline Drive
Orinda and Moraga formations east of the Caldecott Tunnel
Rhyolite above Claremont Canyon
Claremont Chert (you’ll find this familiar)
Spheroidal weathering in Briones Park
Shell Ridge, Walnut Creek
Seems like there could be a lot more.