University of Wisconsin–Madison

Spring Break Trip to Sierra Pampeanas, Argentina

This field trip was made possible by alumni contributions to the department. The faculty and, especially, the students would like to thank the alumni for supporting these field trips, which are an integral part of undergraduate and graduate education.

On a snowy day in March 2006, a group of UW graduate students and professors started a spring break trip to Argentina. Although we got dropped off at the Milwaukee airport (rather than the Madison airport, in order to save money), the weather was sufficiently bad that we had to catch a bus to O’Hare in order to catch our international plane to Buenos Aires. We barely made it. This was the auspicious start of our trip.

Basil Tikoff
Basil Tikoff explains the intricacies of thrust belts.

In fact, we had a fabulous time and learned a lot. The fieldtrip was led by two Argentine colleagues: Dr. Jorge Rabassa and Dr. Claudio Carignano. One could not ask for better geological and cultural guides. Exactly how the fieldtrip got planned is yet another long story, but Jorge had worked with Professor Emeritus David Mickelson and had started corresponding with Toni Simo about a possible field trip. Ultimately, there were three faulty (Alan Carroll, Brad Singer, Basil Tikoff), 12 graduate students, and two undergraduates. We also had the benefit of taking along a department alumnus—Charlie Andrews—who was a great addition to the trip (and a particularly fine walking-around-Buenos-Aires compatriot).

We also tried to do our part for international relations, as each person in the group took a box of academic geology books for the new university in the La Rioja province where Dr. Carignano is a faculty member. Only a group of geologists would consider carrying 15 boxes of books through Buenos Aires as “light” work (paper has very low density compared to rocks).

Carboniferous glaciogenic sandstone/conglomerate valley fill, above unconformity.

We first spent a day in Buenos Aires (seeing where Evita gave her famous address, tangoeing, visiting neighborhoods), getting over the lack of sleep, and getting used to the concept of summer. The next day, after procuring geological maps, we got on an overnight bus to the field area. The next day, we woke up to warm desert day in the province of La Rioja and started doing geology (and unloaded the books).

Sunset in the Triassic fluvial rocks at the Talampaya National Park.

What we saw in the next seven days was amazing. We were principally visiting the Sierra Pampeanas, an area of “Laramide-style”, basement-cored block uplifts. These uplifts are interepretted to occur because of flat-slab subduction underneath South America. Drs. Rabassa and Carignano are geomorphologists, so we spent a lot of time looking at evidence of uplift of the Sierra Pampeanas prior to the on-going Andean orogeny. In fact, we were shown pretty convincing evidence that at least part of the topography was old (Late Paleozoic?) in age, dated by sedimentary rocks in the paleo-valleys.

There were several highlights of the trip. We went up to see the volcanoes on the southern edge of the Puna plateau, including the Cerro Bonete Chico volcano (translated as “Party Hat”, which I must admit it looks like). In addition to the volcanoes, there were cryogenic soils and flamingos in shallow lake basins (at 14,000 ft!). Another highlight was the amazing Talampaya National Park, with its amazing organ-pipe-like geomorphology. And, of course, we can’t forget to mention the empanadas (a mini pasty-type treat we ate for lunch, which worked well until the last day: this is a story you probably don’t want to hear).

The real highlight of the trip was the interaction of people. The graduate students (and faculty) from different areas in the department worked together to understand the different areas. This involved peer teaching and group problem solving (and a fair amount of “winging it” by the professors). Getting to know our Argentine hosts, as well as the people we met when traveling throughout the country, was also wonderful.

Originally published in The Outcrop for 2006, UW-Madison Department of Geology and Geophysics, p. 18.