I almost fell off my stool, but according to this internet site, you’ll roll this “about 1.5 times every 100 rolls.”
So, like, no big deal I guess.
Local ‘grammer @mdwidget fills us in:
According to my Geology of the San Francisco Bay Region handbook, this is Lower Tertiary sedimentary rocks, including sandstone and shale, which started out horizontally as sand and mud on the ocean floor, now tilted and folded as to be nearly vertical. As seen on the #devilsslidetrail #california #bayarea #geology [link]
Now let’s listen to a great Bob Dylan song:
High up in some tall building in the middle of the Mission somewhere, right?