Glacier project students and Amy Myrbo analyzing cores in the LacCore lab.
Submitted by Kelly MacGregor (Macalester College)
Kelly MacGregor (Macalester College) and Amy Myrbo (LacCore, University of Minnesota) and eight Gateway students collected water and sediment transport measurements as well as lake core samples in the Many Glacier region of Glacier National Park, Montana in summer 2018. We spent two weeks in the field collecting data and sampling, and another two weeks at the LacCore laboratory conducting core descriptions and analysis. Students determined that Fishercap Lake was shallow (~1 m deep), and is unlikely to be a significant sediment trap in the valley system. They discovered a layer of gravel below ~50 cm of fine-grained sediment that may represent a period of lake dessication or possibly a major flooding event; radiocarbon dating (ongoing) will help constrain the timing of this event. In addition, Swiftcurrent Lake cores sampled three volcanic ash units from the western U.S., including the Mazama ash (Crater Lake, OR; 7.6 ka) and the Mt. St. Helens J ash (~13.7 ka). Coring along a transect across an inlet delta in Swiftcurrent shows increasing deposition rates with distance from the inlet stream.The students presented their work to Park Rangers, and talked daily with Park visitors during the project. They will be presenting the results of their research at two posters at the Geological Society of America meeting in November 2018.
- Sediment Transport And Deposition In Fishercap Lake And The Swiftcurrent Valley, Glacier National Park, Montana, USA
- Using Lake Cores To Analyze Sediment Transport And Environmental Change In Swiftcurrent Lake, Glacier National Park, Montana, USA
Keck Alaska 2018 research team standing on a thick sandstone bed of the Valdez turbidites near Meares Glacier at the end of Unakwik Inlet, Prince William Sound, Alaska.
Submitted by Cameron Davidson (Carleton College)
The Keck Alaska team made up of John Garver (Union College) and Cam Davidson (Carleton College), and six students, Will Fisher (Union), Victor Garcia (UT-Austin), Nick Gross-Almonte (Carleton), Alysala Malik (Carleton), Caitlin Noseworthy (St Norbert), and Mollie Pope (Union) spent four weeks in northern Prince William Sound, Alaska. We also had the pleasure of being joined by Caitlin’s research advisor, Professor Tim Flood (St Norbert College) for a few days while we were in Valdez. Our field effort included collecting over 70 samples from the Valdez and Orca Groups of the Chugach-Prince William terrane (CPW) along two roughly N-S transects across the Contact Fault. We already have mineral separates from 22 sandstones, with more in the pipeline, and have sent 36 volcanic and plutonic samples to the Hamilton Analytical Laboratory for whole-rock geochemistry. Will Fisher, Alysala Malik, and Nick Gross-Almonte will be using U-Pb zircon dating of detrital zircon from sandstone samples collected along the N-S transects to help constrain strike slip motion across various faults associated with the Contact Fault and to test if the rocks of the CPW were deposited in California and subsequently transported to Alaska, or if they more or less formed in place where we find then today. Mollie Pope is focusing on conglomerates found in the Orca turbidites and is using U-Pb zircon dating of detrital zircon from sandstone clasts to test models of sediment recycling in the CPW basin. Caitlin Noseworthy is using whole rock geochemistry from basaltic volcanic rocks associated with the so-called Glacier Island Ophiolite to test tectonic models for the emplacement of the ophiolite into the Orca turbidites, and Victor Garcia is using U-Pb dating and whole rock geochemistry to determine the age and origin of the Cedar Bay pluton that was emplaced into the CPW late(?) in its history. If all goes well we plan to present this work at the spring GSA Cordilleran Section meeting in Portland in 2019.
The Utah Advanced Program team on the oxidized Navajo Sandstone, south-central Utah.
Submitted by Ben Surpless (Trinity University)
Ben Surpless (Trinity) and four Advanced Program students (Charley Hankla, College of Wooster; Madison Woodley, Mt. Holyoke College; Caroline McKeighan, Trinity; and Curtis Segarra, Trinity) used structural field mapping and video captured by a quad-copter drone to investigate rock deformation within a major normal fault transfer zone, south-central Utah. Our team used these field data to establish patterns of deformation between fault segments, revealing significant variations in both horizontal and vertical networks of fractures and deformation bands in the spectacular Jurassic-age Navajo Sandstone. This summer and fall, our research team has begun computer numerical modeling to test the evolution of the fault-related stress field, assessing how strain produced in modeling compares to strain documented in the field. These results have implications for groundwater flow, oil and gas exploration, and earthquake slip propagation at fault-segment boundaries. Our team will attend a Geological Society of America meeting in spring 2019.
Catalina Gateway participants map tectonic blocks in mélange above clouds using digital mapping software.
Submitted by Zeb Page (Oberlin College)
Nine students along with Zeb Page, Nicollette Mitchell, and Clara Margaret Flood (Oberlin) and Jade Star Lackey (Pomona) used the variability of major and trace elements in garnets from metamorphic rocks on Catalina Island (California) to study fluid flow and melting process in subduction zones. Each group studied samples collected during the 2012 Catalina Keck Project using electron microscopy at Oberlin College, before traveling to California to conduct field work guided by their preliminary lab results. Finally, trace element analyses of garnet and lawsonite were conducted at Pomona College. The students broke up into three research teams each focusing on a particular sample of interest. The “Bee-Gees” looked at major and trace element records of slab melting in a subduction zone through the lens of a garnet amphibolite with large, 3cm diameter garnets. They found that major and trace element patterns were similar in a variety of samples with different garnet sizes and mineralogies, suggesting that similar processes had a hand in their formation. “Eastern Blok” studied metasomatic fluid flow in subduction zones using garnets in a tectonic block with a mineralogically distinct alteration rind, finding that garnet compositions can be used to distinguish garnets formed before, during, and after the influx of fluids. “Schis-toe-city” used trace-element mapping of garnets, a comparison of garnet and lawsonite rare earth element compositions, and back-scattered electron petrography to document the complicated polymetamorphic history of a blueschist block. Each of the three teams submitted an abstract to the fall national meeting of the American Geophysical union, and will present their results in Washington D.C. this December.
An article about the use of drones to study the Sevier fault was recently featured on the Texas Public Radio website. The article, which also includes an audio recording, describes research by Project Director Ben Surpless (Trinity University) and four Keck Consortium REU students to construct 3D models of the Sevier fault system in southern Utah.
Follow this link to view the full article.
Thirty-seven students and ten faculty directors have embarked on six different projects to investigate wide ranging questions about the earth, from soils, to paleoclimate, and tectonics. Two Gateway Projects for rising sophomores will conduct field studies in Glacier National Park, MT and Santa Catalina Island, CA. Four Advanced Research Projects for rising seniors are located in Prince William Sound, AK; the Mojave Desert, NV; along the Sevier Fault, UT; and in the Hanna Basin, WY. Watch the website for updates. See the Gateway and Advanced Research pages for additional information about the projects.