Saturday, May 21, 2016

Day 11 - RIP Eugene

On this fine Cambará do Sul day, we started out with a hearty breakfast at our homely hotel. Our goal for the day: go to the Itaimbezinho Canyon in the national park and try to figure out what actually happened 135 million years ago to form the rocks there. But first, we were struck with a death in the family, as one of our trusty steeds, Eugene, kicked the bucket on the dirt road to the national park. After we paid our respects, we rearranged into the other three cars and made our way to the canyon.



As soon as we arrived at the parking lot, Lydia took off gleefully skipping down the yellow brick road toward the canyon. There, we made observations for the next couple hours, and individually attempted to hypothesize the types of eruptions that created this colossal canyon. There was one very clear horizontal band that showed a break in eruptions, but what else was the canyon wall trying to show us? After this independent deliberation, we proceeded to have yet another glamorous field lunch of meat and cheese sandwiches complete with cucumbers, tomatoes, and a cuddle puddle for Guil’s camera. As soon as the perfect family photo was captured, we brought our deliberations together and compared them to Guil’s best guess; he thought that there were three major bands of rhyolite eruptions, with a basaltic layer at the bottom of the canyon. Additionally, we hypothesized that the middle band of rhyolite was formed by a series of explosive eruptions, but the top layer displayed elements that did not represent either an effusive or explosive eruption, although there were clear signs of effusive eruptions in the paths we walked on.



We put that layer under the table for now and took an extremely odd turn for the afternoon: ECOLOGY! Ecological and yoga guru Jen took the helm at full steam, and formed us into groups of two. She shooed us into the nearby pasture where we picked plots of 1.5 by 1.5 meters and counted the species of flora within those plots. We also had to describe the distribution of each species, as well as a general physical description. Then, after talking about how cows wrecked the flora in this pasture, we proceeded to do the same exercise in the nearby forest, where there were at least four times the flora species present in the plots. We saw how the presence of trees in this forest not only added another species, but also created an entirely new ecosystem for several plant species to survive in. After this short ecological exercise, we walked back to the beginning of the canyon and saw the waterfall and how it continues to actively expand the canyon. As the water eats away at the canyon wall at the base of the waterfall, it is weathering the rock to the point where eventually, the cliff face above it will collapse into the canyon below, creating a wider canyon.

When we got back to the hotel, we were greeted by a surprise: a new steed, the same model as Eugene (but with a radio!) was waiting for us. Affectionately dubbed “Newgene,” this car will join us for the last two weeks of our geological and ecological excursions in Brazil.

Andrew and Nathan


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