Posted by seahunt on June 01, 2002 at 12:39:37:
In Reply to: Re: San Nicolas Island mystery sphere! posted by Brad on May 31, 2002 at 14:56:45:
I've never seen them on the east end.
In any case, what you see can occur anywhere there is good rock layering of relatively soft sedimentry rock. I've written a fair amount about that at the west end of Nic.
If there is a hard layer on top of a soft layer, you get the bathtubs and undercuts below holes that you see at Nic, La Jolla and other places. I'm assuming that the mortar and pestals as I call the holes with round rocks in them, are just another version of this.
I'll have to ask around some and find if I can get you a more specific answer.
Enjoy, seahunt