Elverton Drive is a very distinctive place in the high hills, not so much for its housesthough no insult meant to their ownersas for its bedrock. From end to end, it offers the best exposures anywhere of the Claremont chert.
If it weren’t for the parking situation, this would be a great spot for a class exercise in field mapping. The strata are clear, the winding road offers a range of orientations to refine measurements, and the rock isn’t totally uncomplicated. Take this spot.
What is the nature of the change between neat rows and rumpled layers? What can the student conclude from the evidence, and what should the student look for elsewhere to test those conclusions? I don’t know; I’m just asking and I didn’t inspect this closely. Besides, it might be on someone’s homework.
A few years ago, Elverton was blocked by a landslide. Residents could get in and out from either end, so it wasn’t that bad, but I stayed away until a few weeks ago. I think that this spot must be where it was. (If it’s not obvious, this is sculpted concrete.)
Near the road’s east end is an old excavation, perhaps a small quarry, where you could examine these rocks at leisure and collect a specimen. But do notice the presence of fallen blocks, and if you feel an earthquake while you’re there, step the hell back.
East of Elverton, the chert crosses the ridgeline into the Huckleberry Preserve and trails into the back hills.