Okay, so maybe you recognize that. No? Take another look:



That's tafoni, peppering the Bishop Tuff on the volcanic tableland north of Bishop, California. I went there in September as part of a weeklong GSA Field Forum. Tafoni is a distinctive weathering pattern presumed to be caused by salt weathering, often in sandstones. This particular example wasn't in a particularly salty location, and the rock being weathered was the Bishop Tuff, a welded volcanic ash deposit. But it's clearly the tafoni pattern:



Here's some tafoni resources from the geoblogophere:
Through the Sandglass 1
Through the Sandglass 3
Tafoni from About.com 1
Tafoni from About.com 2
The Dynamic Earth 1
The Dynamic Earth 2
A previous mention here on NOVA Geoblog



And one more... ??

...Just kidding. This last one is a metate, a Native American grain-grinding depression. There were a couple of them at this location, too. Like the tafoni, it's a hole in the rock. Unlike the tafoni, it's man-made. Would you believe we didn't go there for the metates or the tafoni, but some normal faults instead? ...I'll have to share them in a future post.

Labels: anthropology, california, conferences, history, travel, weathering