Welcome to GeoUnion, the graduate student body of the Department of Earth, Environmental and Planetary Sciences. GeoUnion strives to supplement the overall graduate student experience at Rice and DEEPS. GeoUnion represents DEEPS in the overall Rice grad student community, acts as a liaison between students and faculty and organizes a number of intra- and inter-departmental events throughout the academic year.
Date | Event |
---|---|
August 19-23 | O-Week |
September 6-8 | Overnight Camping at San Marcos |
September 13 | Welcome Barbecue |
Cancelled because of Imelda | Pre-GSA talk |
October 12-15 | Field Trip to Big Bend |
October 25 | Halloween Kickball Tournament |
November 26 | Multicultural Thanksgiving! |
Dec 6 | Pre-AGU practice session |
TBA | Enlightenment |
Here’s a list of the resources that you would need to use frequently as graduate students at Rice. The websites of the Rice Graduate Student Association (GSA), Office of International Students and Scholars (OISS), Graduate and Postdoctoral Studies (GPS) are platforms which graduate students can use to keep track of upcoming events, funding opportunities, changes in rules and regulations, etc.
Living in a vast city like Houston and exploring a new place can also be challenging, and so we have compiled a list of recommendations for housing and fun things to do in the Space City!
The effects of internal heating and large scale variations on tectonic bi-stability in terrestrial planets
New student paper out! Matt Weller, publishing in Earth and Planetary Science Letters, finds that planets migrate through tectonic states over time as their surface temperatures change. A planet even can have multiple stable tectonic states over time! [article]
We use 3D mantle convection and planetary tectonics models to explore the links between tectonic regimes and the level of internal heating within the mantle of a planet (a proxy for thermal age), planetary surface temperature, and lithosphere strength. At both high and low values of internal heating, for moderate to high lithospheric yield strength, hot and cold stagnant-lid (single plate planet) states prevail. For intermediate values of internal heating, multiple stable tectonic states can exist. In these regions of parameter space, the specific evolutionary path of the system has a dominant role in determining its tectonic state. For low to moderate lithospheric yield strength, mobile-lid behavior (a plate tectonic-like mode of convection) is attainable for high degrees of internal heating (i.e., early in a planet’s thermal evolution). However, this state is sensitive to climate driven changes in surface temperatures. Relatively small increases in surface temperature can be sufficient to usher in a transition from a mobile- to a stagnant-lid regime. Once a stagnant-lid mode is initiated, a return to mobile-lid is not attainable by a reduction of surface temperatures alone. For lower levels of internal heating, the tectonic regime becomes less sensitive to surface temperature changes. Collectively our results indicate that terrestrial planets can alternate between multiple tectonic states over giga-year timescales. Within parameter space regions that allow for bi-stable behavior, any model-based prediction as to the current mode of tectonics is inherently non-unique in the absence of constraints on the geologic and climatic histories of a planet.
Earth Science ESCI 334 Field Trip
ESCI 334 is one of the Earth Science department’s capstone undergraduate courses. The field trip takes us to a location near San Ysidro, New Mexico, because of the easy access to phenomenal rock exposures, which span approximately one billion years of geological time. Students map in detail rocks that were folded and faulted during the late Cretaceous Period (approximately 70 million years ago), as a consequence of the intense mountain building along the western margin of North America during that time.
During the field campaign, students integrate and apply knowledge they acquired throughout their undergraduate earth science core curriculum. The goal is for students to achieve their full potential in exploring and discovering the geology underfoot. Throughout the field trip students build their confidence in working independently. They make their own scientific observations, which culminate in an interpretive report that transforms their observations into geological understanding.
During the field trip students form bonds and friendships with one another that often extend beyond their studies at Rice. This sort of camaraderie and friendship is in part facilitated by our lodging arrangement. This year the group of students was rather large, but we were able to find a vacation rental on the outskirts of Albuquerque, which had two houses on a single property. Although quarters were tight, this allowed us to share meals and socialize in the evenings, after a hard day’s work in the field.
RUGS Students Visit 1 Billion-year-old Serpentinite
How do you get water back into the mantle? Serpentinites, of course! The main source of water in magmatic arcs like the Cascades comes from altered oceanic lithosphere. Interaction of the seafloor results in extensive hydration of the crust and lithospheric mantle, resulting in the conversion of olivine-rich rocks (peridotite) to a green phyllosilicate-bearing rock known as serpentinite. Studying serpentinites is the key to understanding the global water cycle, at least on million year timescales. What were subduction zones like billions of years ago? There are many examples of Phanerozoic serpentinites, but really old serpentinites are rare. It turns out that we have some ancient serpentinites right here in Texas, in the one billion year Grenvillian orogenic belt that cuts across our state.
Green, green olivine
Peridot is when you’re on show.
Drops of water,
Sooner or later,
You become serpentine.
So the Rice Undergraduate Geology Society (RUGS) organized a one day trip out to central Texas today to look at these 1 billion year old serpentinites. We started out at 6 am in the morning and hightailed out to the Coal Creek serpentinite. We met one of our professors Cin-Ty Lee out there – he had arrived several hours earlier to search for a rare Mexican bird called a Striped Sparrow. A couple of faculty from UT Austin also joined us. The day turned out to crystal clear, with mild temperatures. We could not have asked for a better day weather-wise.
We arrived at the serpentinite outcrop. We immediately noticed that the quarried sections were light green, but the weathered surfaces were red, a common feature of ultramafic terranes. There was almost no vegetation growing on the serpentinite surfaces, in stark contrast to the surrounding amphibolite rocks, which had small live oaks growing on them. We spent a couple hours scrambling over the quarry, trying not to roll our ankles, all the while pondering what type of peridotite protolith this was. Was it oceanic lithosphere, fore-arc lithosphere, sub-arc lithosphere, or back-arc lithosphere? How would we tell? Does the serpentinite represent a suture between the collision of two continents? What we all agreed upon was that this serpentinite looked old! No hints of fresh olivine anywhere, but everywhere, there were hints of serpentinizing fluids in the form of syndeformation veins. We also found a couple of local samples that appeared as if they were originally troctolites based on relic cumulate texture.
After having lunch on these green rocks, we decided to head to Enchanted Rock to look at granites up close and personal. Unfortunately, when we arrived, the park had reached its capacity for the day and they were not letting in anymore visitors until 3 PM. So we went back towards where we had just come from and stopped to look at an unconformity where Proterozoic granites and migmatites were overlain by Paleozoic limestones. A hundred million years missing beneath our feet! We spent a half hour crawling over some beautiful exposed migmatites and discussed what conditions are needed to melt the lower crust.
Daylight was running out, so we thought we would take one more shot at getting into Enchanted Rock State Park. We arrived there with only about 2 hours left of sunlight and a long line of cars inching their way through the entrance. We eventually got in with enough time to climb to the top of one of the granite domes. It was a nice way to end the day! Participants (see our group shot above) included from left to right: Elli Ronay, Xun Yu, Detao He (behind Xun), Larisa LaMere, Sriparna Saha, Michael Farner, Lexi Malouta, Rachel Marzen, Jackie Rios, Adeen Denton, Tierra Moore, Emily Paine, and Cin-Ty Lee (taking the picture!).
IMPORTANT NOTICE
Because of COVID-19, the field trip is being postponed to later (date TBD) this year. The seminar will continue via remote meetings through the end of the Spring 2020 semester.
As earth scientists we seek to understand the natural processes that have shaped the world around us through time. The most fundamental requirement to acquiring a deeper understanding of these mechanisms is through observation. EEPS has a strong heritage in field-based research that when combined with analytical excellence, produces skilled scientists with a broad view of Earth as a system. While Rice University is well placed to take advantage of a broad array of research resources, students in Houston do not always have immediate access to nearby geological sites that represent Earth as a system.
A generous gift from Mike Johnson enables EEPS students the opportunity to observe classic and fundamental geologic concepts in the field. Students are in charge of proposing, selecting and managing a field excursion that will benefit everyone in the department. A year-long seminar-based class run by the students prepares them to visit the locality they have selected. Papers are selected, presented and discussed, followed by activities that educate the students on how to run a field-based project. During the field excursion, elected stops will be led and presented by individual students. The knowledge gained before and during the field trip will cumulate into a multi-media field guide that will be made available to the department and public following the trips conclusion.
A significant benefit of a department-wide field excursion is the interaction of students with scientists from various disciplines. Many earth scientists only carry out field work with specialists in their own field. The real discoveries in modern earth science occur when the different disciplines are part of a collective discourse. This trip will have scientists with different backgrounds observe the same outcrops; fostering fruitful discussion that results in the generation of new and unique questions. In addition, this trip may inspire fellowship among EEPS graduate students that will hopefully create life-long collaborations and a cohesive department.
General route starting in Albuquerque, New Mexico
This year, EEPS elected to utilize Mike Johnson’s gift to lead graduate students on a 7 day field expedition to observe some of the most diverse and economically important geologic terrains in the United States.
In early June of 2020, EEPS will travel through New Mexico, Colorado and Utah, which have easily accessible exposures of metamorphic, sedimentary, and igneous rocks. Starting from Albuquerque, New Mexico they will explore the Rio Grande Rift, the San Juan Volcanic field, and the well exposed Mezozoic stratigraphy on the Colorado Plateau. Observing these diverse geologic terrains will give EEPS graduate students a chance to see how their research interests dovetail with what they observe in nature and provide opportunities to create new ideas.
Pre-Trip planning seminars
Fall semester: The graduate student of the winning field trip proposal organizes a weekly reading group focusing on the regional geology of the four corners region and come up with potential stops.
Spring semester: The weekly reading group continues. Students pick the final outcrops that they would like to visit. Each student is assigned to be an expert on 1-3 stops. Before the field trip, each student will submit their description(s) of their stop for the field guide.