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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