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Geology student researchers present in big numbers

The 2016 UW-Eau Claire CERCA event, the Celebration of Excellence in Research & Creative Activity, took place on April 27-28, and the Department of Geology was once again one of the most well represented departments on campus.

Poster presentations were made to represent the 15 different faculty-student collaborative research projects in geology, including the work of 30 students and 10 faculty mentors. That's pretty impressive! See the following excerpt from the program which outlines the projects, presenters, and mentors.

Comparisons of Estimates of Hydraulic Conductivity in the Unsaturated Zone
Kinzey Stoll, Justin Dowling
Faculty Mentor/Collaborator: Kent Syverson                                       

The main objectives of this research are to assess the effectiveness of ground penetrating radar (GPR) techniques for estimating hydraulic conductivity at multiple depths at the field scale and to determine the infiltration parameters needed to implement this technique. UWEC researchers have recently shown that GPR techniques can be used to estimate hydraulic conductivity and that hydraulic conductivity estimates from GPR data appear to vary with depth. Additional data acquisition using conventional methods for measuring hydraulic conductivity at different depths is needed to evaluate the variations in hydraulic conductivity indicated by the GPR data. Another important aspect of this research is to determine the infiltration parameters needed to provide the constant rate of infiltration Additionally, accurate estimation of hydraulic conductivity using GPR techniques requires constant (steady state) infiltration over the depth interval being investigated; this research seeks to determine the duration and intensity of infiltration needed to establish constant infiltration for a range of sampling depths and soil types using numerical simulation and laboratory column experiments. The results of this research can be used to generate practical guidelines for estimation of hydraulic conductivity in the unsaturated zone that would be of great interest to the agricultural and geological communities.     


Diagenetic History of Cambrian Sandstone Units in Western Wisconsin: Implications for Resource Extraction
Justin Poirier, Ray Fliflet
Faculty Mentors/Collaborators: J. Brian Mahoney, Kent Syverson            

The Wonewoc Jordan Formations in the upper Midwest were deposited as cratonic sheet sandstones during Late Cambrian eustatic sea level changes. These formations, comprised of quartz arenite, are highly valued by the petroleum industry for hydraulic fracturing due to its ultra-pure composition, round, high-strength grains, and weak cementation. The diagenetic history of these formations is poorly understood, and is important for both economic and environmental reasons. Petrographic analysis of the Wonewoc and Jordan formations quantifies the composition of framework detrital grains and interstitial cement. Framework grains are primarily monocrystalline quartz (95%), polycrystalline quartz and microcline. Interstitial spaces are occupied by voids, calcite, sericite, authigenic orthoclase feldspar, and hematite. Variation in the composition and quantity of interstitial material within and between formations suggests a complex multistage diagenetic history of orthoclase feldspar cementation, dissolution, multiple calcite cementation events, hematite cementation, and a final dissolution event. One of the primary environmental concerns with frac sand mining is the potential for the generation of crystalline silica particulate matter. This fine-grained material would most likely be derived from cements during processing. However, silica cement is very rare, is restricted to the upper Jordan contact, which renders the material non-economic because it inhibits disaggregation.        

Evaluation of Nanoparticles and Colloids in a Public Water Supply from Well-Head to the Consumer Tap
Sarah Kintner
Faculty Mentor/Collaborator: Robert Hooper                                            

Nanoparticles (NP) are nanometer (1-100nm) sized amorphous to crystalline solid materials that are ubiquitous in low-temperature natural environments, and many NP are being synthesized for use in industry. Manmade NP are appearing in many urban public water supplies. NP’s small size results in large effective surface area; consequently, NP chemical characteristics differ from similar bulk materials characteristics. We evaluated natural NP from three wells, mid-treatment and from two consumer taps to evaluate NP throughout the public water supply distribution system in Eau Claire WI. Samples from the water supply were analyzed using Transmission Electron Microscopy and particle composition was determined by energy dispersive x-ray spectroscopy. Each of the three wells had distinctive NP compositions but the major components were primarily amorphous CaCO3 and Fe-Mn oxides enriched in Silica, Mg, P, Sulfate and Cl. Zinc was a common trace element in almost all NP. Tap water samples rarely contained significant NP concentrations and none of the samples contained NP of real concern for public health. The Eau Claire treatment process appears to effectively remove both natural NP and NP made during water treatment. Unlike Flint MI, the Eau Claire water supply has very low levels of NP of any environmental concern.            


Geologic Mapping and Petrologic Modeling of the Green Mountain Shield Volcano, Oregon
Chase Friedemann, Forest Friedrichs
Faculty Mentor/Collaborator: Phillip Ihinger                                                          

External Faculty Mentor/Collaborator: Samuel Castonguay, Treasure Valley Community College                                                                                               

The Green Mountain Shield Volcano (GM)—dated at 740,000 Ka—is located in Eastern Oregon at the intersection of the Oregon High Lava Plains Province and the northernmost Basin and Range Province.  In a preliminary study, Friedemann and Friedrichs (2015) observed minimal variation in geochemistry across the suite of GM lavas. In this study, we refine our petrologic model of the GM Shield Volcano through detailed geologic mapping as well as additional geochemical analysis using XRF spectroscopy on a more complete suite of GM basalts. We compare the GM lavas to an additional, yet much older, volcanic province in western Oregon: the Siletzia terrane. Our geochemical results confirm that the Mg# of the GM suite of lavas remains constant suggesting that all GM magmas experienced a similar degree of crystal fractionation. Our results also show that the GM basalts are geochemically distinct from the Siletzia basalts as well as others. Additionally, we have procured a radiometric age (40Ar/39Ar) for the basal sequence of the GM shield volcano by collecting samples from the ‘lava lakes’ in the center of one of the erupted maars: 891.7 ± 183.5 Ka.            

Geology of the Precambrian Rocks Hosting the Flambeau Volcanogenic Massive Sulfide Deposit in Rusk County, Wisconsin
Zacharie Zens
Faculty Mentor/Collaborator: Robert Lodge                                                

This investigation examines the geochemical and petrographic characteristics of the volcanic strata hosting the Flambeau Cu-Au volcanogenic massive sulfide (VMS) deposit in Ladysmith, WI. Research on the deposit essentially ceased after the mine closure in 1997 and the site has been successfully reclaimed. This study revisits the volcanic strata hosting the Flambeau VMS deposit through examination of historic drill cores to describe the geology in light of almost 20 years of advances in the fields of geochemistry, economic geology, and the tectonic evolution of the region. Flambeau mine drill cores were re-logged and analyzed using X-ray Fluorescence and Inductively Coupled Plasma Mass Spectrometry. This new geochemical data was compiled with historic mine maps and cross sections to develop a coherent scientific model describing the nature and evolution of the volcanic and hydrothermal system that hosts and formed the deposit. The Flambeau deposit formed as a series of stacked ore lenses in a rifting arc geodynamic setting where a submarine volcanic arc was undergoing extension and likely developing a back-arc rift. Geochemical alteration indices reveal that a pre-metamorphic sericite-chlorite-pyrite mineral assemblage formed along with ore-forming hydrothermal circulation. These results are currently being prepared for publication in peer-reviewed journals.            

Geology the Eisenbrey Zn-Cu-Pb Deposit, Rusk County, WI
Nathaniel Jackson, Bruno Henrique De Moura Merss
Faculty Mentor/Collaborator: Robert Lodge                                               

The primary objective of this research is to study the geological characteristics of the poorly understood Eisenbrey Zn-Cu-Pb deposit in Rusk County, Northwestern Wisconsin. Volcanogenic massive sulfide (VMS) deposits are significant sources of metals such as zinc, copper, lead, silver and gold in the form of sulfide minerals. Despite the proximity of the Eisenbrey deposit to the more infamous, past-producing Flambeau Cu-Au VMS deposit, there has been essentially no research completed on the rocks hosting the Eisenbrey nor has there been any volcanic and tectonic linkages made to the strata hosting the Flambeau. Understanding the tectonic and metallogenic framework of the Eisenbrey and any potential genetic relationship to the Flambeau deposit will significantly improve our understanding of the Precambrian geology of northwestern Wisconsin. Initial phases of research included re-logging and sampling of historic drill core collected during mineral exploration. The samples of the metalliferous ores and their host rocks are currently being analyzed to determine their petrographic and geochemical characteristics and to re-interpret the economic geology of this region.            

Infrared Spectroscopy of Quartz and Feldspar in Alpine Hydrothermal Veins
William Fitzpatrick, Eric Brinza, Steven Brost
Faculty Mentor/Collaborator: Phillip Ihinger                                       

With the aim of discerning fluid conditions present during hydrothermal activity associated with Alpine metamorphism, we present new results on the abundance and distribution of hydrous impurities in co-crystallizing hydrothermal feldspar and quartz crystals.  The crystals were extracted from a hydrothermal vein in the Lepontine Zone of the Swiss Alps.  Gemmy specimens of coexisting albite (Na-feldspar) and quartz are analyzed using infrared spectroscopy at high spatial resolution (100-μm spot sizes).  We note the presence of distinctive absorption bands associated with each mineral type.  We observe absorption at 3450, 3270, and 3100 cm-1 in all spot analyses of feldspar wafers.  The abundances of the three bands range over an order of magnitude (100-1400 Abs/m at 3450 cm-1; 30-600 Abs/m at 3270 cm-1; and 20-200 Abs/m at 3100 cm-1) and co-vary smoothly with one another as our analytical traverses approach and cross structural features, including cleavage fractures and twin planes.  Within the quartz crystal, abundances of HOH, LiOH, and AlOH (at 3400 cm-1, 3380 cm-1, and 3480 cm-1, respectively) also covary with one another.  We explore the potential that infrared measurements have for discerning variations in fluid conditions present during and subsequent to crystal growth.            

Mapping the Precambrian Bedrock Geology of Rusk County
Samuel Helmuth
Faculty Mentor/Collaborator: Robert Lodge                                         

The primary objective of this project is to create a new regional geologic map of Rusk County, Wisconsin, highlighting the characteristics of the Precambrian bedrock hosting the past-producing Flambeau Cu-Au mine and various other metallic mineral deposits in northwestern Wisconsin. An updated geologic map of this region, along with petrographic and geochemical analyses of the volcanic and intrusive rocks will help constrain the volcanic and tectonic setting and will provide an improved framework for exploring for additional metallic mineral deposits in the Penokean orogen. Over the past year, field mapping and sampling of Precambrian bedrock outcrops in the rivers, roadcuts, and quarries throughout Rusk County were completed. In addition, samples of bedrock from drill core were also obtained in regions with no exposed outcrop. Petrographic and geochemical analyses of these samples were completed to fully characterize the rocks and interpret their geologic histories. This new data was integrated with compilations of historic maps and USGS aeromagnetic surveys in ESRI® ArcGIS software in order to produce a modern, re-interpreted geological map. This new map contains additional information such as geochemical plots and photographs of samples. The project is currently being prepared for publication with the Wisconsin Geological and Natural History Survey.            

New Zircon U-PB Ages for the Choiyoi Silicic Large Igneous Province of Argentina that Define a Strong Episodic History of Magmatism and Mass Extinction in the Permo-Triassic Time
Carly Mueller, Samantha Bartnik, Adam Wiest
Faculty Mentor/Collaborator: J. Brian Mahoney                                   
External Faculty Mentor/Collaborator: David Kimbrough, San Diego State University                      

The Choiyoi magmatic silicic large igneous province (SLIP) of central and southern Argentina and Chile (23°S-42°S) was emplaced along the eastern edge of Gondwana in Permo-Triassic time.  This magmatic province qualifies as a SLIP due to: 1) aerial extent of ~500,000 km2 and variable thickness of at least two kilometers, 2) dominate rhyolite-ignimbrite composition, 3) the correlation of Choiyoi magmatism to widespread Permian ash falls, and 4) strong episodic magmatic record over ~30 m.y.  The 26 new laser ablation ICP-MS zircon ages for Choiyoi rocks from two key transects in Mendoza (32°S) and San Juan (33°S) define strong bimodal age distribution with peaks at ~246 Ma and 266 Ma. The older peak dominates the distribution encompassing 20 of 26 ages that are statistically indistinguishable and which yield a weighted mean age of 265.9 ± 1.0 Ma (95% conf.). This ‘flare-up’ is documented strongly in a compilation of all available zircon U-Pb ages over the extent of the province (25°S–40°S) and the Neogene foreland basins. The ~266 Ma peak represents a short duration (1-6 m.y.) of silicic volcanic activity that overlaps with several end-Permian events and extinctions, including Olson’s extinction event marking the transition from basal synapsids to therapsids.            

Petrographic Analysis of the Flambeau Sulfide Ore Body
Maile Olson
Faculty Mentor/Collaborator: Robert Lodge                                            

The Flambeau volcanogenic massive sulfide (VMS) deposit was the only one of several potentially economic deposits to be extracted in Wisconsin. Despite being a source of essential base and precious metals such as copper, zinc, and gold, a limited amount of research has been published on this deposit and company  reports focused on the secondary enriched ore that was the only part of the ore body to have been extracted. This project is designed to examine the mineralogy, texture, and composition of the ore body and to determine the base and precious metal phases that are present in the primary ore zone. Petrographic and geochemical analyses of ore-forming minerals have helped constrain the nature and evolution of economic mineralization. The current phase of this research project has involved mineral analyses of polished thin sections of Flambeau ore samples.  Using the SEM in the Materials Science Center at UW – Eau Claire, the habit of gold alloy grains have been documented. Research utilizing reflected light petrography and the SEM has improved the identification of ore minerals, their chemistry, and characterization of the precious metal mineral-hosts. The data gathered here is contributing to a larger study that is seeking a complete a geochemical and petrographic understanding of Wisconsin’s VMS deposits.            

Quantifying Grain Shape Characteristics and Fragmentation in Raw and Processed Frac Sand from Western Wisconsin
Kaelyn Blotz
Faculty Mentors/Collaborators: Geoffrey Pignotta, J. Brian Mahoney        

Different sand formations, including the Wonewoc and Jordan, are mined in western Wisconsin in part for frac sand, which is used in hydraulic fracturing for hydrocarbon extraction. Health concerns regarding frac sand mining exist in part due to the possible presence of fine grained respirable silica, which if inhaled by human lungs in high volumes over extended periods of time could cause a respiratory condition known as silicosis. One possible source for this respirable silica could be fracturing and fragmentation of sand grains during processing.  To determine the extent of fracturing and fragmentation of sand grains, representative samples of raw and processed samples were analyzed manually and digitally. Samples were manually point-counted from different sand formations to determine a baseline for raw, unprocessed sand. Representative raw sand yield < 3.2% fractured grains while representative processed sand yield < 3.7% fractured grains. To further quantify characteristics of raw and processed sand including degree and size of fragmentation, digital image analysis techniques were utilized to examine grain shape characteristics, such as roundness, sphericity, circularity, and roughness. Comparing digital and manual results shows statistical similarity between the two methods. Digital image analysis allows for a rapid and more statistically robust of grain shape.            

Schematic Illustration of Evolving Tholeiitic and Calc-Alkaline Magmatic Systems: New Models
Eric Brinza
Faculty Mentor/Collaborator: Phillip Ihinger                                             

The dramatic contrast in the geochemical evolution of tholeiitic and calc-alkaline magmatic systems has remained an enigma since their original characterization nearly a century ago.  Recently, two new models that describe the evolution of each magma type have been developed that explain the enigmatic features observed in the classic intrusions of each magma type (Ihinger, 2015).  The long-standing paradoxical observations within the tholeiitic Skaergaard (Greenland) and the calc-alkaline Shonkin Sag (Montana) intrusions are now understood to represent magma chambers wherein evolved felsic liquids have buoyantly segregated from a host residual crystal mush.  Here, we present our efforts using Adobe Illustrator to schematically illustrate the processes that lead to the geochemical and textural variations observed in the crystallized intrusions.  We support these illustrations with actual thin-section photomicrographs taken from the intrusions.   Our images document the evolving geochemistry of both residual liquid and complementary crystal phases throughout the duration of crystallization.  Our representations capture the details of the chemical evolution and show the roles that the processes of crystallization, liquid immiscibility, and compaction play in the development of each magma intrusion.            

Severe Weather Siren Protocol in Eau Claire: Does It Produce Intended Responses?
Jacob Larson, Lucy Horst, Kyle Tollefson
Faculty Mentor/Collaborator: Scott Clark                                                   

This study was conducted to investigate UWEC students’ knowledge, perceptions, and behaviors (KAB) of outdoor siren alerts in the City of Eau Claire. The city activates outdoor warning sirens whenever the National Weather Service issues a severe thunderstorm warning or a tornado warning for the city. The same sound is used for both severe thunderstorm and tornado warnings. Our hypothesis is that this practice may lead individuals to dismiss the potential risks associated with an approaching storm if they have repeatedly heard the sirens for storms that did not produce any strong winds or damaging hail. A Qualtrics survey was sent to students enrolled in six introductory geology courses. The survey asked students about their KAB related to the city’s outdoor sirens. Coding of responses revealed that many students are confused or do not know why the sirens are activated. The use of the same warning sound for severe thunderstorms and for tornado warnings causes students to take all siren alerts less seriously. If the city used different sounds for each, students state they would respond appropriately for tornado warnings, but not for severe thunderstorm warnings. Warnings of severe thunderstorms need to be taken as seriously as tornadoes. We recommend that the City of Eau Claire invest efforts into improving the public’s awareness of the warning siren protocol and into explaining why severe thunderstorms need to be taken as seriously as tornadoes.            

Tracking Basin Inversion in the RetroArc Foreland Basin:  Integrated Provenance Studies in the Cacheuta Basin, South-Central Andes
Samantha Bartnik, Adam Wiest, Carly Mueller
Faculty Mentor/Collaborator: J. Brian Mahoney                                   

Integrated stratigraphic, sedimentological, geochronologic and the thermochronology analyses of Neogene sedimentary successions yield a high fidelity record of organic exhumation and basin inversion within the RetroArc Foreland Basin of the south central Andes.  Neogene synorogenic strata of the Cacheuta basin record episodic sediment flux produced during eastward thrust belt propagation.  Initial basin subsidence is constrained as Early Miocene (19.20 +0.26Ma) by U/Pb geochronology on a tuffaceous sandstone near the base of the succession.  Provenance analysis identifies detrital contributions, in decreasing order of abundance, from syndepositional Miocene volcanism, Cordillera Frontal (Permo-Triassic clasts and detrital zircon), Precordillera, Cordillera Principal and Cordillera Costal (Jura-Cretaceous zircon).  Sediment influx and depositional rate vary systematically upsection, with the highest sedimentation rates reflecting elevated volcanism and rapid accumulation of tuffaceous sediment, and lower sedimentation rates corresponding to progradation of conglomeratic units dominated by Cordillera Frontal rhyolite, Precordillera metasedimentary clasts, and, Cordillera Principal carbonate and conglomerate clasts. Detrital apatite (U-Th)/He thermochronology records the initiation of rapid basin inversion at ~4-5 Ma.  Detrital apatite (U-Th)/He ages in strata younger than ~9.7 Ma match syndepositional zircon U/Pb ages, and apatite ages in strata older than ~9.7 M progressively decrease downward, and are consistently younger than volcanic tuff U/Pb ages.


Geology and Materials Science Center

Surface Water and Groundwater Chemistry of Western Wisconsin: Establishing an Environmental Baseline
Samantha Bartnik, Adam Wiest, Carly Mueller
Faculty Mentors/Collaborators: J. Brian Mahoney, Stephen Sellwood, Laurel Mc Ellistrem                                                                                       

The primary objective of this investigation is to conduct the first comprehensive analysis of surface water and groundwater chemistry throughout western Wisconsin. This analysis will establish an important environmental baseline that documents background variations in dissolved metal content in surface water and groundwater throughout the region. This environmental baseline is essential for accurate assessment of potential public health risks and identifying the source of these metals.These data are vital to the development of reasonable and responsible environmental safeguards that will facilitate economic growth and sustainable development of the silica sand industry while protecting water resources in western Wisconsin.  This investigation focuses specifically on concentrations and mobility of metals that are naturally occurring in geologic units in western Wisconsin. The study area encompasses surface water sampling sites between Barron and Tomah, Wisconsin, northeast of the Mississippi River and southwest of Medford, Wisconsin, in the northeastern upper Mississippi River watershed. The baseline established by this investigation is critical for the development of regulations on Nonmetallic Mining Operations in Wisconsin, and the results of this investigation will be of considerable interest to regulatory agencies (i.e. WDNR), scientific organizations (i.e. WGNHS and USGS), environmental groups, the silica sand industry, and the general public.