I've been doing a bit of surfing today. I have to confess that everything actually stemmed from reading macros on LiveJournal. Yes, I am aware of how unbelievably stupid they are, but some of them can be quite funny, so I started my day of surfing at LolScience.
That, in turn, led me to the maintainer of the community who has a very sensible blog, Green Gabbro. In fact, that was what retriggered my desire to have a place where I could ramble on to my hearts content about rocks 'n stuff.
Also found All of my Faults are Stress Related and the Science Blogs. So far I've only read bits of Pharyngula, but I think I might give some of the others a try.