Last Day at Monturaqui

Thursday and Friday, Dec. 11 and 12

Thurday turned out to be my last day at Monturaqui. Ingrid and I started on the south side of the crater and followed a gully around the outer slopes of the crater for most of the day. Our hope was that we might find some iron shale that had washed away from the flanks of the crater. We followed the gully as long as we continued to find melt rock, picking that up while searching for rusty colored shaley bits of rock. Meanwhile the other crew of Nathalie, Edmond, and Carlos combed through one of the small ejecta lobes, also searching for anything that fit the iron shale description or that was magnetic enough to make the compass needle spin. It seemed especially hot out, since Ingrid and I were blocked from the breeze down in the gully. We were pretty exhausted and ready for a shower and a nap when we finally went back to the cars, but at least we had some more impactite to show for our efforts. Our fieldwork at Monturaqui is finished for this year, but we have more samples than I think anyone expected, so there is plenty of lab work ahead.

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Sarah scouring the gully for impactite

Friday the Iowa crew decided to check out a few different sites. I have been working on samples from Laguna Lejia and David has been working on samples from Cerro Overo, and since we are both here now Ingrid thought it would be a good idea for us to actually see these incredible places! We took the short (but slightly more difficult) road to get to Lejia first. The route included a very sketchy road through a very steep ravine, a significant climb in elevation, lots of birds and wildlife, and unbelievable views of Lascar Volcano and others. When we finally got to the laguna it was briskly cold outside and super windy, but there was enough sun to stay warm. We looked at several outcrops of the carbonate rocks and sediments from the paleolake terraces. Ingrid even showed me exactly where some of my samples came from. We also took time to snap a few photos of the lake and the reflections of the volcanoes in the background.

Next we drove up a little higher to check out Cerro Overo. This is an incredible maar volcano crater located not far from Chiliques, another volcano that sticks out of the Altiplano behind the crater. Just inside the rim of the crater there is a large basalt outcrop that blocks the wind nicely. We sat there in the sun for our lunch break, enjoying the view from just under 15,000 feet. After lunch I went to check out another outcrop, David grabbed a few more samples, and we all took several photos before heading out. We decided to take the longer road home, to see some new scenery. We got much closer to Lascar on the way out, and David and Ingrid picked up samples from a couple different volcanic flows to use for teaching purposes. It was both a productive and beautiful way to cap off our work here, and future University of Iowa Geoscience majors will have a lot of Chilean rocks to study.