Chisel #2: Low-tech

Posted by Ellen

That's me with the chisel in my mouth, some summers ago, during geologic field work in the North Cascades, in the state of Washington. I'm climbing a hill called Lincoln Rock that rears up about twelve hundred feet above the apple orchards along the banks of the Columbia River. We'd been told there were some good garnet coronas up there--garnets with white rings around them---the metamorphic feature I was trying to interpret for my thesis project.

We'd also been told that Lincoln Rock was the one place in the North Cascades where a geologist named Bob Miller--a man who climbed cliffs for fun when he couldn't think of an excuse to climb them for research--fell badly and almost cracked his head open. This was my last day in the field that summer, and though I'd had wonderful fun, I was beginning to shift gears mentally, to look forward to getting back home so I could stop worrying about slipping and falling and leaving five children motherless.

Perhaps because of Bob's misadventure, but surely also because I was old and out of shape, I was by far the slowest climber. While I toiled upward inch by inch in the August sun, the rest of the gang was already lolling about in the shade of an overhang at the top of the hill, eating lunch and making fun of me. As I finally approached the scene of this snapshot, a Ph.D. student named Carlos Zuluaga asked if I wanted my picture taken. Then he suggested I put the chisel in my mouth. It seemed like a good idea at the time, it really did.

Anyway, there were indeed nice-looking garnet coronas all over the hilltop, and Carlos and the others kindly helped me smash them out of the outcroppings. We all made it down safely, with rocks in our backpacks. When I got a look at my Lincoln Rock samples under the microscope, however, I discovered that the garnets were rotten; they'd cooled too slowly after their metamorphic odyssey, and a mineral named chlorite had replaced much of the garnet. My thermodynamic models wouldn't work on rock with rotten garnet, so I put the Lincoln Rock samples in a drawer in the basement of the geology building, and maybe they are still there today.

Fortunately, I had plenty of other samples. And I'd love to be back up there again.....