After nearly a week, the unrest of “Mama” Tungurahua has become evident in the city of Quito, in the form a a thin film of volcanic ash. It’s most visible on cars, not unlike the road salt that covers cars back in Ohio. But this accumulation come comes from the thick haze across the valleys of the Inter Andean region of Ecuador.
Dissipating ash cloud near sunset
There are few countries more interesting than Ecuador for a Geology student like myself. I’m spending the second semester of my Junior year studying at a University in Quito, Ecuador’s capital and second largest city. Surrounded by 5000 m mountains and numerous active volcanoes, the city provides the perfect vantage point for observing …
(From left) Dr. Greene, Cory, and Conner after summiting the 11,947 ft. Vandever Mountain at Mineral King, with Mt. Whitney in the distance.
After nineteen days in sunny California, Dr. Greene, Cory, and I have returned to Ohio. Our field session was a great success, giving us scores of samples to begin analyzing in the coming weeks. Dr. Greene was an excellent field leader for us new geologists, and a big thanks goes out to him and his parents for hosting us during our days in San Francisco. The trip was a tremendous learning experience, and what better location than the beautiful Sierra?
The Mineral King Valley is located within Sequoia National Park, a few hours east of Visalia, California. …
Though we aren’t searching for gold, some of here in the Geo department do “rush” to California, but in search of a different mineral. Zircon is the keystone to much of the petrographic and volcanological research going on this summer. As Liz wrote earlier, there are different ways to get from a chunk of outcrop to the tiny zircon crystals that we can date. Both of us have used the “heavy liquids” in the lab for a density separation, but there is also another interesting method. That’s where gold comes in.
One method we have been experimenting with to separate zircon uses a “gold table”, the same thing that bearded prospectors use to get placer gold out of fine sediment. …
Zircon, or zirconium silicate, is a hardy mineral that typically forms in igneous systems like volcanoes. It is hardy because it is not easily broken down by weathering processes but can remain intact for billions of years. In fact, the oldest mineral so far discovered on Earth is a zircon mineral that is 4.4 billion years old. For reference, the Earth is 4.56 billion years old so zircon minerals are capable of being heated and squeezed repeatedly for many years without breaking down. This convenient property of zircon as well as the abundance of radioactive elements incorporated in its structure such as Uranium and Thorium allows researchers to date magmatic systems of all ages. Uranium is an element that decays …
At last we have gotten to the zircon! This last step requires mad-scientist lab gear and some heavy liquids. They’re called heavy liquids because they are relatively dense- and this is what we are using for the final type of separation to get to the teeny tiny zircon. Zircon is a dense mineral (about 4.6 g/cm3) and will sink to the bottom of the slightly less dense heavy liquid, methylene iodine (3.3 g/cm3), while the majority of the other grains will float. (For reference, water has a density of 1 g/cm3).
Did I mention that methylene iodine (MEI) is a carcinogen? That’s why I get to wear this lovely getup (see below).
Like I …
We tried to put it off but we could not avoid it- it is time to tackle the Frantz. The Frantz is a rather noisy machine that separates the magnetic and nonmagnetic components of our sample by running the grains between two electrically charged magnets. The point of all this is to further isolate the zircon minerals that we will be analyzing.
The crushed samples is fed into a funnel at the top right of the machine and travels between the magnets where it is separated into two buckets.
The only problem is that the machine has not been working properly. However, after fiddling with it for some time, I came across a video that made us a little less …
Summer has arrived in Granville. Warm winds suddenly change to thunder, and the Bluecoats’ music rumbles through campus. For some of us geoscientists, this signals the time to become enthralled in summer research. My second week of research work is coming to a close, and I’m not getting down to the nitty-gritty of why I’m here. Though I had never done summer research at Denison before, a semester of Directed Study led right in to crushing rocks on day one.
My summer will be all about zircon, the tiny crystals in many igneous rocks whose composition and structure allows scientists to gather data like ages and formation environments from isotopes within each crystal. My advisor, Erik Klemetti, will be studying …
Hello all! This summer I am back at Denison working on a project with Professor Erik Klemetti involving the magmatic evolution of the Lassen volcanic system in Northern California. Lassen is the southernmost volcano in the Cascades Range and has had eruptions as recently as 1915. Our goal is to analyze the zircon minerals that we extract from various samples representing different eruptions and phases of the system. We hope to have a better understanding of the composition, interactions, and overall evolution of Lassen’s magmatic system from this project. To get to the zircon, however, much pounding, sorting, and separating must take place.
Thus far, I have been focusing on samples from Eagle Peak which are 66 ka …
The 2012-13 school year has begun here at Denison, and tradition dictates that all the hardworking research students get to show off the science they’ve done. This year three Geoscience majors presented their summer research at the annual Summer Research Symposium. Check them out:
Mariann Bostic, presenting on stratigraphy of the earliest stages of the Kungurian Stage in the Pequop Mountains, Nevada(advisor: Kate Tierney)
April Strid presenting on models for carbon cycling in soils due to land use (advisor: Tod Frolking)
Amy Williamson presenting on pressure and temperature determinations for the Eagle Lake Pluton, California (advisor: Erik Klemetti)
Job well done … and now onto their senior year!…
Even though several groups of scientists hold different opinions on the prediction of the ENSO’s frequency in the future, they all agree that the predictions depend on many other complicated processes such as cloud feedback, etc. Therefore, so far no one can give a comprehensive answer to the future ENSO’s frequency. In this post, I will explain two extreme theories of the prediction.
Figure 1. Predicted temperature anomaly along the Pacific Ocean. The east shows a large increase of temperature, while the west warms up relatively in a small degree.
Timmermann et al. demonstrate that El Niño’s frequency would possibly increase due to the increasing carbon dioxide concentration (Timmermann et al., 1999). The model, developed by Roeckner in 1996, shows …