August 14, 2012
[I don't want to leave!]
A tremendous day to end a tremendous field session! Again, I am blown away. By the rocks themselves and our luck to find their fossils, by my incredible new geology friends, by the whole adventure of it all. I could not have imagined a better trip.
We have enough exciting fossils and rocks to publish a new interpretation of this sequence, and to reveal important events following the mass extinction. We went far beyond the fundamental questions I posed in my proposals. And, we have a mind-boggling collection of fun challenges for the future.
We went to the site by the farm today, and the farmer indeed left the gate unlocked for us. Almost no fossils to see there, but plenty of sedimentary structures. When the waves interact with bits of sand and shell on the seafloor, they can leave lasting marks in the rocks. 200,000,000 years later, I’m interpreting these layers of sand and shell and muck to determine the history of the environment where our animals lived.
A key challenge of this expedition is tackling several different field sites. This way, we can see the conditions in different parts of the environment that simultaneously recorded responses to the mass extinction.
The last site of the trip was spectacular, and the highest elevation, in the Sierra Nevada range. I’d been marginally interested after a preliminary scout session on Saturday. Then, yesterday morning Julio brought me cores from Sierra Nevada, and I knew I wanted to see it with my last remaining half day.
WOW. So many fossils, so many peculiar associations. In fact, these rocks looked most like my material from Nevada. I spent three hard years banging my head (well, my rock hammer) against those rocks before finding their secret of sponges. Now, it seems like Mission: Impossible Fossil is my specialty. This afternoon, I was looking at rocks equally frustrating. I’m riveted!
A crucial skill in geology is reconstructing the history of a pile of rocks. Fossils are great, but they can only inform us about mass extinction ecology – specific animals at a specific time – if we can organize the rocks into relation with others. If we can discover the correct stratigraphic order, the correct sequence of the rocks, then we have a guide. Sure, rocks are often stacked on top of each other. But what about when they point straight at the sky? Or when they twirl around and flop over on themselves. Picture a gigantic taco shell made of 40-foot thick rock. That’s what I saw today.
Over lunch – fried trout from tiny family farms – Julio and I talked about jobs and vacations and vocation. He’s an exploration geologist. His life, like mine, is full of daily mysteries, and mysteries that take years to tackle. He’s been looking at this taco shell of rock for six years.
Today we searched for and found fossils. Together we collected notes, photos, observations, and samples for microscopic analysis. Raul is stellar at finding fossils, it turns out, and chiseled out a half dozen for me while I photographed those too tough to remove.
We were at close to 14000 feet of elevation today. Conveniently, the site led to a steep slope with a road at the bottom, so the drivers pulled the trucks around and then met us half way. Easy! Still I got winded – glad I ran all those stairs back in LA.
Dark clouds moved in and the cold sharpened in a persistent wind. Julio and Armando and I agreed it was time to go, and we were only half way down the slope. Wouldn’t you know, we kept sighting more fossils all the way down. We kept agreeing to leave, then finding something too good to pass up – just a photo! Just a photo. Finally, it started snowing. Snowing. OK, OK, now I will get off the rocks.
There was just a bit of snow but it was already five, and Raul would have to drive in the dark on the windy roads down to his valley hometown In the lessening light and sprinkling snow, I gathered all my samples, exchanged contact info, goodbyes and hugs all around. Man I hate to leave these rocks. I hate to leave this countryside and I hate to leave these damn fine geologists. But everybody’s got other fish to fry, and I have a hunch I’ll be back.