Yucatan Field Course

UF students in Merida
It was a busy first week for students attending the UF in Merida (Yucatan, Mexico) Program.  After arriving in Merida on the evening of June 17, students met on Monday (June 19) at the Centro Institucional de Lenguas, where they study Spanish.
On Wednesday, they headed for the town of Izamal, where they visited a technical university, interacted with local students, reaped the benefits of the culinary arts program, and encountered some of the gaily decorated horses and carriages in the main square (Photos 3-5).

Students enjoying culinary arts program Picture of gaily decorated horses and carriages
On Friday, it was off to the organic farm of Dr. Juan Jimenez, where students learned about cultivating dragon fruit, a native climbing cactus that blooms for one night only. It is know locally by its Maya name, pitaya.  The UF students also instructed a couple of students from the University of Yucatan on details of the “Gator Chomp”.
Gator chomp
Image of Dragon fruit
Dragon fruit
Then it was on to the town of Dzitya, where local artisans work with tropical hardwoods and local limestone.  Although they use power tools today, they used to rely on more traditional tools to work wood, like the foot-operated lathe.
Image of local artsian work with tropical hardwoods
Next, it was off to the archaeological site of Dzibilchaltun, where the group visited the “Temple of the Seven Dolls” and saw some of the local fauna, such as the ubiquitous “black iguana.”  Much as today, the ancient Maya “mined” the local rock to create their infrastructure, such as buildings and roads.  As you look around Williamson Hall, note that so much of what you see ultimately came from the Earth (walls, windows, desks, light fixtures, tiles, bathroom sinks and toilets, etc.).  Everyone was pleased to have the opportunity to take a dip in Cenote Xlakah, a sinkhole where the underlying aquifer is exposed.
Image of black iguana
Picture of temple of seven dolls
Students swimming in Cenote Xlakah
The next day, it was off to the west coast, and the town of Celestun.  Students toured the long coastal lagoon via boat, stopping at the “ruins” of an old village previously involved in salt production.  Heavy rains made it necessary to wade along parts of the inundated old road.  The lagoon is bounded by a barrier peninsula and rimmed by mangroves (4 species).  The very productive coastal lagoon system is a source of aquatic resources (e.g. crabs) , and is home to a large population of flamingoes.
Image of students riding boat
Picture of flamingoes at lake
At Valdiocera Spring, which discharges into the lagoon, we had the good fortune to see a young tiger heron.
Picture of young tiger heron
Full picture of young tiger heron

On the road to “Ground Zero,” where the Chicxulub meteorite struck 65M years ago.

Students at Las Coloradas, the 2nd largest salt production site in Mexico. In the background is a mountain of salt, precipitated in evaporation ponds.

Students covered in carbonate clay at Rio Lagartos


Group picture of students at beach
Image of sunset at Rio Lagartos

Image of black iguna

A group of caterpillars (“zatz”) on a tree trunk. At night they move up into crown of the tree to feed on leaves, but during the day, they aggregate, probably for defense against predators.

 

Using Noise to Monitor Permafrost


UF Geological Sciences PhD student Stephanie James has been advancing new methods to use seismic noise to monitor seasonal changes in depth to ice in Alaskan sediments. With co-authors from Sandia National Laboratory and UF, she recently published a paper “Improved moving window cross-spectral analysis for resolving large temporal seismic velocity changes in permafrost” in Geophysical Research Letters. This paper was selected as a recent “Editor’s Highlight”.
Stephanie James completed her PhD in May and received a National Science Foundation Postdoctoral Fellowship to continue her research in this field. She will be collaborating with researchers at the US Geological Survey in Colorado.

Using Noise to Monitor Permaforst

Greenland project aims to develop a understanding of weathering across forelands of retreating ice sheets

Ellen and Jon Martin led three NSF-funded field deployments to Greenland over the past two summers, for a total of 20 weeks in the field.  The project introduced 2 UF Postdocs, 2 PhD students and 3 undergraduates to high latitude field work in remote locations, and has employed additional undergraduates to help analyze samples back at UF.
The goal of the project is to sample two types of streams in Greenland, those that drain ice sheet meltwater from newly exposed landscapes and others that drain annual precipitation and permafrost melt (no glacial water) from more mature landscapes.  The team analyzes the chemical composition of these two stream types to determine how they differ and how those differences may vary over a range of time scales from daily, to annual, to millennial.
Jon Martin, Andrea Pain (Postdoc), Scott Schnur (PhD student, Emory University), Mark Robbins (PhD student), and Hailey Hall (undergraduate) sampling waters and gas exchange along a river outside of Sisimiut, a town of ~1500 residents on the west coast of Greenland. (Photo by Ellen Martin)

Their results should contribute to our understanding of how weathering in these two types of streams affects delivery of nutrients to the ocean as well as the amount of carbon dioxide in the atmosphere and the oceans to help refine predictions of future responses to ice-sheet retreat and to provide context that will allow scientists to interpret past ice-sheet retreats and climate changes, based on chemical records.

See information about ongoing NSF-funded Greenland Research aimed at developing a holistic understanding of weathering across forelands of retreating ice sheets: https://grainfluxes.geology.ufl.edu/

GeoClub Summer 2018 Field Trip – Missouri and Arkansas

The trip: organized by GeoClub officers Ashlyn Spector, Nikita Kepezhinskas, and Graduate student Anthony Pivarunus, exposed sophomore and junior undergraduate students to excellent examples of igneous and sedimentary geologic structures in the St. Francois Mountains of Missouri and the highlands of Arkansas.

St. Francois Mountains
Over the course of three days, students practiced rock and outcrop identification and descriptions, as well as a mock mapping assignment in local roadcuts, outcrops, and quarries. Students were split into groups of two or three (upper-level student with a lower division student) and introduced to the area’s extrusive and intrusive features.
Students were familiarized with the geography of the area, frequently identifying major rivers, hillocks, ridges, and other defining topographic features. Students were stressed the importance of systematic note taking-comments on notes were compiled each night during the trip by Anthony Pivarunus and Nikita Kepezhinskas.
The last full day in the St. Francois Mountains was spent on two large-scale activities. The first being a roadcut exposing ignimbrite, a micro gabbro dike, and Paleozoic strata was given as practice in rock identification, outcrop sketching, and geologic history construction. The second activity involved rudimentary mapping introduced at Johnson Shut In’s State Park. Students practiced mapping the contacts of three rock units (rhyolite, siltstone, rhyolite) in a defined area, along with providing relative thickness and simplified rock descriptions on a final map.

Arkansas Highlands
After our time in the St. Francois Mountains, students were given a brief overview of Arkansas geology with stops at Buffalo National River (Ozark Plateau), Mt. Nebo State Park (Arkansas River Valley), Hot Springs National Park (Ouachita Orogeny), and Crater of Diamonds National Park (Ouachita – Coastal Plain transition).
At Buffalo National River, students completed basic outcrop sketches and rock identification. A small hike lead the group to an overlook exemplifying the interaction between imbedded rivers and uplifting plateaus.
At Mt. Nebo State Park, students were introduced to the concepts of hogbacks, razorbacks, cuestas, and mesas and how each morphologic feature expresses larger scale geologic structure. At a scenic overlook over the Arkansas river valley, students were given an exercise to identify the underlying geologic structure of the river valley using the exposed topographic expression.
At Hot Springs National Park, students took a tour of the historic bath houses in the park. A geologic map in the museum provided an excellent opportunity to explain the complex fold and thrust structure of the Ouachita Mountains and its relation to the park. Students were able to view one such active hot spring and taste the water from the park.
At Crater of Diamonds National Park, several students were introduced to lamproites. A review of kimberlitic and lamproitic pipes and geology was administered. Several excellent outcrops of lamproitic magma, breccia tuff, and ash tuff gave excellent context to explaining maar eruptions.

Human Activities Create Corridors of Change in Aquatic Zones

Thomas Bianchi and Elise Morrison’s article in AUG’s EOS addresses the need to establish aquatic critical zones (ACZ’s) and understand how human manipulation of the surface through canals, dammed reservoirs, irrigation ditches, and pollution effects species diversity, microbial communities, and nutrient levels in aquatic zones across the planet. Through this research, they hope to get a full picture of the extent of the Anthropocene and understand how these changes will continue into the future as climate change.

Photo Credit: iStock.com/AlexKazachok2