Phase II of the Oregon State University geology tour supplemental lingers round one building only, but what a building!
Stop 7. Gleeson Hall 1
So here’s a rock type I get very excited about, not because it’s fantastically beautiful, but because I find it fascinating. Travertine! I loves travertine. Travertine is a type of limestone, but it forms from solution rather than critters, and it’s got all sorts of weird voids and textures, and it can form from so many things – hot springs! Cold springs! Lakes! Streams! Ponds! Seeps! Basically, if there’s water full of the stuff limestone is made of, it can precipitate out travertine. Evelyn can tell you why travertine’s important.
Now we’re going to tear ourselves away from the travertine here, and go round the other side of the building to
Stop 8. Gleeson Hall 2
Here’s a nice transitional shot: we’re still looking at travertine (and note how the portions that bear the brunt of the weather show it!), but our eyes are also drawn by the big pink steps…
Those stairs are wild, people. Pink porphyritic granite, with enormous phenocrysts. Megacrysts? Could be!
Right. That brings us to the end of Phase II. Phase III will include some marble halls, and some extremely creative photo editing as I struggle to overcome the limitations of photographing subtle gray patterns in gray stone in gray twilight…