Collaborative Research: Field-based Projects Exploring Geophysical Methods, with Applications to the State of Vermont

Laura Webb & Keith Klepeis, University of Vermont; Dave Westerman, Norwich University Introduction This proposal outlines a collaborative approach to acquisition and sharing of geophysical equipment that will facilitate the offering of field-based curricula in the application of geophysical methods to geological, environmental, and archaeological studies at the University of Vermont (UVM) and Norwich University (NU). Both universities have a tradition of successful undergraduate research in collaboration with the Vermont Geological Survey upon which we will build with new opportunities afforded by acquisition of the proposed equipment (ground-penetrating radar, electromagnetic induction, seismic refraction, and sub-meter Global Positioning Satellite technology). We will also be exploring collaborations with the UVM Department of Anthropology and its Consulting Archaeology Program and ways to broaden the interest in the new curriculum at UVM to include undergraduates in other majors such as Anthropology and Geography, and thus offer group projects and undergraduate research opportunities that span the disciplines. Newly acquired instrumentation, along with existing instrumentation, will be shared by both universities. Because the main field-based courses using this equipment will be offered alternating years at UVM and NU, the cooperative sharing of key equipment will maximize its impact and efficient use. Through inquiry-based learning, students will gain experience in experiment design and deployment of geophysical equipment to collect subsurface data that will be integrated with geological constraints to solve real-world geological and environmental problems deemed as priorities by the State of Vermont. Institutional Contexts

University of Vermont. UVM is a comprehensive mixed public-private institution with an enrollment of approximately 9,000 students. The Department of Geology is part of the College of Arts Sciences, which functions like a small private liberal arts institution within the larger university. Enrollment in the College is approximately 5,000 undergraduates and 1300 graduates (primarily master’s degree students with a handful of a few doctoral granting departments) and student-faculty ratios are ~16:1. The largest classes that a student might take in their first year enroll nearly 200 students but after the first year class sizes are much smaller, between 25–45 students. In the Geology major, class sizes average 10–12 students. Enrollments for the 2008–2009 academic year include 33 Geology majors (20 BS, 13 BA), 14 Geology minors, and 5 students in the Environmental Science program with Geology concentrations. The small size of Geology classes, combined with our location in a geologically rich and diverse region, makes it possible for field trips and field-based projects to be the focal points of most courses. The Department operates a fleet of four ten-passenger vans to support field trips. Approximately 10% of graduating seniors currently do independent research (see list of recent undergraduate theses in supplementary documentation), however this number is increasing annually, and newly implemented degree requirements for a BS in Geology now require an independent research project. The Department has two endowment supported grant programs to support these projects.

There is a distinguished tradition of field-project courses in the Geology Department, including a first year student field-based introductory geology course that has been a very successful recruitment vehicle for geology majors (Drake et al., 1997). This course is followed in the sophomore year with a field methods class that introduces students to the techniques of observation and data collection (Klepeis & Mehrtens, 2004). Students leave Field Geology with fundamental skills that are built on in many subsequent classes. Because Field Geology will be a prerequisite course for the new Geophysics course being developed, and we believe that this

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class demonstrates tradition and expertise in field-based student projects, the fundamentals of this course are described here in further detail.

Although using field-based classes in geology instruction is common, offering a “field camp” type of academic offering in a student’s third semester is, to our knowledge, unique (Klepeis & Mehrtens, 2004). Field Geology is based on three to five projects studied by teams of two to three students that meet for four-hour field labs twice a week. During this time students develop expertise in some of the “first principles” of field geology (e.g., cross-cutting relationships, laws of superposition, criteria for identifying geologic features, etc.) by conducting self-contained exercises that, over the course of several weeks, are pieced together to reveal the geologic history of the study area. Each project replicates the process that “real geologists” go through in the field. Over the course of the semester the projects build on previously developed skills, for example, mapping more complexly deformed terrain, or projects that involve synthesis of previously studied area, thus building on a student’s observational, quantitative, analytical and communication skills. At the conclusion of the field component of each project, students use the Department’s computer laboratory where they apply software programs useful for the display and interpretation of their data to produce a professional-style report that synthesizes field, map and graphical information. These reports require students to follow a logical progression through the scientific method they employed in the field. At least one project in the semester also involves preparation of a power point presentation that follows the format of a professional meeting. This type of learning demonstrates to students, through practice, how both faculty/professional geologists and students construct new knowledge, develop a deeper understanding of problems, and present our conclusions to the public.

The problem-based and inquiry-based learning approaches used in Field Geology are methods considered as effective in enhancing scientific literacy (Siebert & McIntosh, 2001). The pedagogical strategies employed in this course are aligned with the seven basic principles that Chickering and Gramson (1987) identified as characteristic of effective undergraduate learning experiences: (1) encourage faculty-student contact; (2) encourage cooperation among students; (3) encourage active learning; (4) provide prompt feedback; (5) emphasize time on task; (6) communicate high expectations and (7) respect diverse talents and ways of learning. These tested and successful approaches of Field Geology will be used in the new Introduction to Exploration Geophysics class.

Norwich University. NU is the nation’s oldest private military institution with an enrollment of approximately 2,000 students, with approximately 60% participating in the Corps of Cadets. The university offers majors in traditional liberal arts disciplines, as well as in professional programs of engineering, business, architecture and nursing. The university maintains an overall student-faculty ratio of ~16:1. The Department of Geology and Environmental Science is located within the School of Mathematics and Science, and freshman enrollment levels have risen steadily for the past three years, averaging 4 Geology majors and 7 Environmental Science majors. Freshman classes in Geology have target enrollments of 40 students with lab sections of 20 students, and upper-level courses average 9 students. The Geology program is strongly field-oriented, with the campus centrally located in Vermont on the eastern flank of the Green Mountains within 2 hours of Canada, Massachusetts, New York and New Hampshire.

All Geology and Environmental Science majors are required to do field-based independent research in the fall of their senior year, and many of our students participate in the Norwich Summer Research Fellowship program. Geology majors and all Environmental Science majors with concentrations in the sciences or engineering are required to take Field Geology.

The NU Field Geology course, offered in alternate years with recent average enrollments of 16, has historically included a 5-week emphasis on exploration geophysical methods since the university acquired a suite of instruments in 1985 via a 50% matching NSF equipment grant. The course meets for 75 minutes one day each week and for a 5.5-hour lecture-lab block on a

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second day. During most weeks the second day is dedicated to lab, and several times each semester the lab is extended to allow for more involved projects. The title for this course is scheduled for change to Field Geology and Exploration Geophysical Methods for fall 2010.

Department personnel are actively engaged in research within Vermont (Barg et al., 2001; Becker et al., 2008; Dunn, 2006, Dunn and Springston, 2006; Dunn et al., 2004; Eliassen and Springston, 2007; Filip et al., 2008; Kim et al., 2006, 2009; Larsen et al., 2003; Miller and Dunn, 2009; Springston and Dunn, 2006a, 2006b; Springston and Kim, 2008, Springston and DiSimone, 2007; Westerman and Coish, 2008; Westerman, 1987, 1996). This engagement with their own research, often in collaboration with the Vermont Geological Survey, allows for a wealth of continuously new field exercises with students addressing questions for which the answer is not yet known. This approach provides students with experience similar to what they will encounter in the work force setting.

Students in Field Geology learn to operate all the geophysical equipment and to interpret the data they collect during their seismic, electromagnetic, magnetic and gravity studies. Such studies generally apply multiple methods to the problem. For example, many glacial lake deposits in the valleys of central Vermont contain magnetite-rich sands, having derived their sediments from the glacial materials picked up as ice traveled over the upstream greenstone horizons. Norwich students (Geisler et al., 1993) have investigated the magnetic character of these sedimentary basins to reveal buried valley profiles by inverting the magnetic data, with controlling parameters provided by seismic studies to determine of depth to bedrock and gravity studies to determine sediment thickness.

In addition to the required Field Geology course, a number of students subsequently choose to do semester-long, independent geophysical studies that lead to course reports with occasional publications (Hague, 1986; Gainer and Lukaskiewicz, 1988; Lovett, 1991; Geisler et al., 1993; Orton, 1993; Locke, 1995; Donahue, 2001; Primiano, 2002; Thompson, 2006). Student projects commonly involve extension of previous work, exploring the unanswered questions raised in those studies, and requiring that students learn how to integrate their work to existing databases.

Vermont Geological Survey. The Vermont Geological Survey conducts surveys and research relating to the geology, mineral and groundwater resources and topography of the State of Vermont. The Survey is located in Waterbury, Vermont which is approximately halfway between UVM (Burlington, Vermont) and NU (Northfield, Vermont). It is directed by Laurence Becker, State Geologist, and employs two Geologist/Environmental Scientists, Marjorie Gale and Jon Kim. George Springston (Research Associate, NU) works closely with the Survey on funded projects on a contract basis.

Consulting Archaeology Program at UVM. The Consulting Archaeology Program (http://www.uvm.edu/~uvmcap/) shares building space in Delehanty Hall with the Geology Department. The program is involved in a variety of efforts that include review and compliance studies required by state and federal regulations, research projects, educational outreach, and provides independent and work-study opportunities to current undergraduates. Major research themes include human interaction with the natural environment, technology, and regional trade and exchange. New Curriculum and Undergraduate Research Opportunities

Pedagogical design. The pedagogical approach underlying the course design for developing an Introduction to Exploration Geophysics class at UVM is grounded in combining inquiry-, field-based, and collaborative learning approaches in existing classes. It goes without saying that field work is an essential element to learning geology. There is abundant literature on the educational impact of field work, both geological and geophysical, on students (e.g., Witten, 2003; Barret et al., 2004; May & Gibbons, 2004; Lord et al., 2003; Bogner, 1998; Nundy, 2001; Mooney, 2006; Lonergran & Andresen, 1988; Fuller et al., 2003; Clark, 1991; Huntoon et

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al., 2001). As these authors have described, the learning outcomes of field work are not just academic objectives of improved ability to do science, but other transferable skills are acquired as well. For example, most field-based projects pair or group students (e.g., Barrett et al. 2004), and group work is important key skill to employers (Dunne & Rawlins, 2000; Mooney, 2006) as it develops student ownership of the research problem and fosters interactions among students which mimic those that will occur later in the workplace. Inquiry-based learning provides students with “hands-on” experiences that model the process of scientific investigation. Inquiry-based learning has been shown to be more effective than traditional classroom approaches in the sciences for both women and minority students (Byrne, 1994); indeed, the National Science Education standards identify inquiry-based learning as the preferred method for teaching science. With inquiry-based learning, students engage in many of the same activities and thinking processes as scientists (NRC, 2000). As summarized by Piburn et al. (2002), “learning occurs best in situations that are complex, problem-based, realistic and reflective of the actual content of instruction”. Project-based learning is the ideal vehicle for such inquiry. When students participate in the collection of field-based real-world data they gain first-hand experience with the constraints and limitations of data collection and hence, how it can be interpreted. The geoscience education community has embraced inquiry-based learning (e.g. Woltemade & Stanitski-Martin, 2002, George and Becker, 2003; Baker, 2006; Apedoe et al., 2006; Lev, 2004; Carlson, 1999) as an effective way to improve critical thinking skills.

In addition to using well tested pedagogies such as inquiry and field-based, collaborative learning, the proposed new geophysics class will develop a new pedagogical approach to enhance undergraduate training. We will be collaborating with the Vermont Geological Survey as we select sites for class projects. Although there are examples in the literature of collaborations involving community groups and environmental organizations (e.g. Knapp, et al., 2003), there are few (Tedesco & Salazar, 2006) examples of collaborations with local and state governments. We describe below an existing model for a state-university collaboration that we have utilized for senior research projects at UVM and which will be the template for the projects described in this proposal.

The Collaborative Model: An example of undergraduate research in collaboration with the Vermont Geological Survey. The goal of Karen Derman’s senior project at UVM was to investigate relationships between major bedrock structures and the location of bedrock well yields in Williston, Vermont (Derman et al., 2008). The impetus for the project was that housing and other developments in Williston have been stalled by low groundwater well yields. A field project was designed to help evaluate possible correlations between well yields, lithology, the presence and orientation of lithologic contacts, and the location of specific ductile and brittle structures. The structural data was compared to regional fracture data to establish potential mechanisms for the development of regional fracture sets. The significance of this research is based in pertinent environmental issues, including the delineation of bedrock aquifers and naturally-occurring arsenic contamination.

Detailed bedrock geologic mapping was conducted in the Williston Quadrangle during the summer of 2007 in collaboration with geologists at the Vermont Geological Survey. A geologic map was constructed that includes unconsolidated (glacial) sediment, as well as bedrock sedimentary rocks of Cambrian to Ordovician age. Comprehensive ductile and brittle structure data sets were also collected during the mapping and integrated with photolinear data derived from airphotos and yield information from domestic bedrock wells. Frequency-azimuth rose plots and equal area nets of ductile and brittle data were used to determine the dominant fracture azimuth in each rock unit mapped. Soil and rock radioactivity were measured using a new portable Geiger counter. The goal of this aspect of the project is to determine if areas of concentrated radioactivity correlate with large fractures where enhanced groundwater flow was predicted.

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The bedrock geologic map of the Williston area shows that the town is underlain by metamorphosed Late Proterozoic–Cambrian rift to drift stage clastic rocks that structurally overly Lower Cambrian–Middle Ordovician carbonate and clastic continental shelf sedimentary rocks on the west side. These sections were juxtaposed by the west-directed Hinesburg Thrust during the Ordovician Taconic Orogeny (Figure 1). Recent logs for domestic groundwater wells demonstrate that this thrust can be penetrated at depths ranging from ~100–1000’ depending on where the well is drilled relative to the thrust front; these wells frequently have high yields.

Figure 1. Excerpt of bedrock geologic map draped over LIDAR data, and geologic cross section from Kim et al. (2007). Red lines in cross section are wells that penetrated the Hinesburg Thrust; wells that did not penetrate the thrust are indicated in blue. Well yields are shown in gallons per minute.

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Rocks in the upper plate of the Hinesburg Thrust underwent four phases of ductile deformation. The dominant foliation (SD) in these rocks is a NNE-trending gently east-dipping S1/S2 composite spaced cleavage formed by two generations of isoclinal folds. Asymmetric shear bands also locally define S2. Bedding is only preserved in S1 microlithons. SD was deformed by NNE-trending, tight, asymmetric, gently plunging, and west-verging F3 folds with an axial planar crenulation/fracture cleavage. Whereas F3 folds can be identified conclusively in lower plate rocks, S1 and S2 cannot be consistently correlated across the Hinesburg Thrust boundary. Open F4 folds with steeply-dipping E-W trending axial surfaces warp all earlier structures. Frequency-azimuth fracture plots show multiple statistical peaks with ~E-W trending fractures being dominant. Pronounced linear topographic patterns observed on slope maps generated from LIDAR data are consistent with the orientations of ductile and brittle structures in the bedrock. Cross sections that were drawn across Williston and Hinesburg from well and structural data demonstrate that the Hinesburg Thrust surface is irregular. The results of this work were presented at the 2008 Geological Society of America Northeastern section meeting (Derman et al., 2008). Ongoing analysis seeks to correlate the Hinesburg Thrust subsurface morphology with elements of its complex structural history.

New Curriculum in Geophysical Methods. This project will result in permanent offering of new curriculum as well as new opportunities in undergraduate research for students at both UVM and NU. NU will be offering a Field Geology and Exploration Geophysics course in the fall of even years. UVM will begin offering Introduction to Exploration Geophysics with a field and laboratory component in the fall of odd years.

The new Introduction to Exploration Geophysics course at UVM will have both a lecture and laboratory component. Initially, lectures will focus on theory and laboratories will emphasize application. Students will develop skills in geophysical field methods (e.g., seismic refraction, ground-penetrating radar, electromagnetic conductivity) on small, guided projects on and near campus. These projects will facilitate student familiarity with instrument deployment, data collection, processing and interpretation. Several potential targets areas have been identified as appropriate for both our available equipment and methods and the need for guaranteed access in mind (i.e., UVM property or city parks). For example, at Townline Brook landslides have exposed a stratigraphy of gravel over sand over clay in a cliff wall. Geophysical data can be collected on a flat area on top of the cliff such that data profiles can be compared directly with an exposed section of the geology. Other examples include possible depth to bedrock investigations at Lone Point Meadow, UVM Fields, Redstone Campus Athletic Fields, and Oak Ledge City Park. The Barge Canal is open access area and Super Fund Site associated with an old coal gasification plant where the local stratigraphy includes artificial fill (sawdust) over coal tar, swamp deposits, and glacial to post-glacial sediments. Aquifers, including a perched water table, can be investigated at sites such as the UVM Fields.

The semester will culminate in a final project involving a field area at which the Vermont Geological Survey needs subsurface information. Students will design experiments to address the identified problem, including instrument type and strategies for deployment. Working in groups, students will then collect, process, and interpret the geophysical data, and will synthesize the geophysical data and existing data (e.g., surface geology, well log data, etc.) The groups will present their results in 15 minute GSA-style presentations followed by discussion and debate. State Geologists will be invited to attend the presentations and participate in discussion. A final written report by each student will be turned in following the presentations; copies of reports and data sets will be made available to the Vermont Geological Survey.

An example of a possible class project would be groundwater-related studies in the Town of Williston, Vermont, discussed earlier in the proposal. Logs from groundwater wells drilled in the region demonstrate that the Hinesburg Thrust is folded and that wells penetrating the thrust have higher yields than do shallower wells. The subsurface geometry of the fault and fracture systems has important implications for groundwater resources in the area. While the

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LIDAR data and field studies reveal much about the geometry of folds and faults, surficial deposits cover much of the area. Therefore, geophysical investigations of aquifers and depth to bedrock would be highly beneficial to revising the existing structural models and groundwater exploration strategies. Importantly, students would see a direct societal benefit and application of their efforts.

While we have initially conceived the UVM Introduction to Exploration Geophysics course with Geology undergraduate students in mind, we will actively be looking for ways to broaden the interest in this course to include undergraduates in other majors such as Anthropology and Geography (c.f. Barrett et al., 2004), especially in light of our ability to explore collaborations with the UVM Department of Anthropology and its Consulting Archaeology Program and thus offer group projects and undergraduate research opportunities that span the disciplines.

Undergraduate research. In addition to using geophysical instrumentation in the course curriculum, we anticipate its use in undergraduate research projects. One issue of concern to the Vermont Geological Survey is quality assurance and quality control of the geophysical data sets and interpretative models produced during the class projects. A senior research project following up on the geophysics class project is one mechanism for acquiring additional geophysical field data and refining the products of the class project for use by the Survey. As the Survey will have access to software utilized in courses at UVM and NU, students can work closely with both faculty and State Geologists. The involvement of George Springston will provide in house knowledge of equipment, experimental protocols and software use at the Survey that will greatly facilitate collaboration. We anticipate an abundance of opportunities for student research utilizing the equipment in collaboration with the Vermont Geological Survey, the UVM Consulting Archaeology Program, and UVM and NU faculty, with applications in environmental geology, surficial geology, archaeology, stratigraphy, geomorphology, and structural geology. Examples of applications relevant to possible field exercises, course projects, and undergraduate research are briefly described below with information regarding the equipment and techniques that are the focus of this proposal. Geophysical Equipment, Techniques and Applications

Seismic refraction. Seismic refraction techniques have extensive applications throughout the geosciences. The standard shallow seismic refraction technique involves generation of a compressional sound wave at a source and measuring arrival times at a string of geophones placed at increasing distances from the source. Subsurface velocity variations and depths to layers can be inferred by analyzing the time-distance relationships of these first arrivals. Although the literature related to the subject is extensive, an excellent understanding of practical applications of shallow refraction techniques can be obtained from Ackermann et al. (1986), Haeni (1988), Kearey et al. (2002), Parasnis (1997), and Redpath (1973). Ackermann et al. (1986) and Parasnis (1997) provide particularly useful descriptions of how to deal with real-world seismic profiles involving complex refractor topography and lateral variations in refractor velocity. Each of the references cited above includes at least some discussion of the problems posed by low-velocity layers and the lack of resolution of thin layers of higher velocity material.

As with all geophysical methods, the seismic refraction method by itself does not always lead to a unique solution. However, if reversed seismic profiles are employed in conjunction with intermediate shots and beyond-endpoint shots, the solutions commonly become quite constrained. This is particularly true if the seismic method can be applied in conjunction with other geophysical methods and/or subsurface borings.

Many studies in Vermont and the northeastern United States have effectively used seismic refraction surveys to provide important subsurface information for groundwater, surficial geology, and engineering applications (Haeni, 1995); Springston, 2000; Stewart, 1971, 1973). Seismic refraction surveys can reliably provide a good indication of the depth to the water table

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and to bedrock (Haeini, 1995). They can commonly provide a good indication of the depth to dense till (Haeni, 1995; Springston, 2000).

The numerous seismic refraction profiles undertaken since the 1980s by the NU investigators have amply demonstrated that the use of a sledgehammer source and careful stacking of signals is quite adequate for most of the studies that we anticipate undertaking. With our longer 110-meter geophone cable we have commonly been able to discern bedrock refractors at depth somewhat beyond 35 meters if there is sufficient space to permit beyond-endpoint offset shots and the seismic noise from traffic or construction is not too excessive. NU has recently ordered a 165 meter geophone cable with 15-meter geophone spacings to help us “see” depths of up to at least 50 meters.

We anticipate that the enhanced filtering capabilities of the new seismograph/software combination will help us deal with the high seismic noise situations. Although simple seismic refraction problems involving level topography, two or three layers, and parallel boundaries are simple to solve with algebraic formulas and a spreadsheet, the analysis becomes much more complex when multiple, non-planar, and non-parallel layers are involved. The SeisImager/2D software will enable us to apply the delay time and tomographic inversion methods of seismic refraction analysis and undertake ray-tracing of subsurface models. These new capabilities will enable students to produce much more realistic models of the subsurface materials.

Sample Project: NU owns a hillside cemetery that overlooks the NU campus in the Dog River valley. A recent embarrassing moment raised considerable concern in 2004 when preparation of a plot for a prominent alumnus revealed less than 6 feet of sediment resting on the local metamorphic bedrock. Fortunately, this occurred when Field Geology was in progress and the 11 students in the class carried out a seismic survey using the department’s Geometrics Model ES-1225F 12-channel seismograph. Shot points were chosen to reduce intrusion on the site while maximizing the number of depth-to-bedrock solutions for the survey. Data was extracted from printouts as well as from the screen, and solutions to the simple two-layer problem were carried out manually. Additional data constraining bedrock depth was acquired by driving rebar rods to refusal, and knowledge of the general porpoising pattern of local glaciated bedrock surfaces was assessed to provide guidance in contouring (Figure 2).

This exercise provided an unexpected, real-life opportunity for students to produce a marketable product using a wide variety of skills and knowledge that they had acquired earlier in Field Geology and in other courses. Similar exercises are available in abundance, given the number of settings with sloping and/or undercut layered glacial deposits that exhibit sharp rheological contrasts amongst themselves and with the underlying bedrock, and for which hazard assessment is needed.

Ground penetrating radar (GPR). GPR utilizes pulsed high frequency electromagnetic

waves to image the subsurface in a manner analogous to seismic reflection. For GPR, the critical factor that controls wave speeds in geologic materials is permittivity (dielectric constant). Reflections (and refractions) occur at interfaces of materials with different permittivities that can be a function of both lithology and water content (e.g., the top of the water table itself may be a reflector). An antenna transmits a pulse that is nanoseconds in duration at a given frequency and either the same antenna or a second antenna receives reflected waves and records a two-way travel time from reflecting surfaces at depth.

GPR surveys with our proposed instrumentation from Geophysical Survey Systems, Inc. can be conducted in various fashions, for example: 1) Data can be acquired in moving-mode operation with a single antenna (monostatic; 200 or 400 MHz) acting as both transmitter and receiver to produce a time-distance record (e.g. two-way travel time plot of reflectors versus distance traversed) over a transect line. 2) The two antennas can be specified as a transmitter/receiver pair (bistatic) with a fixed offset and data can be collected at regular intervals over a transect line. 3) The bistatic system can be used to collect a common-midpoint

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survey with an initial offset between antennas that is progressively increased symmetrically over a line of transect. The advantage of the moving-mode monostatic setup (1) is the speed and ease with which a survey can be collected. The advantage of the bistatic fixed-mode setup (2) is flexibility depending on ground conditions and the ability to record different polarization components. The advantage of bistatic common-midpoint surveys (3) is that velocities can be determined to refine two-way travel times and thus improve the geologic model. Surveys can be directly integrated with GPS for sub-meter position accuracy, or distance can be recorded with an attached survey wheel, or by tape measure to record position information. Data can be viewed in real time in the field with the SIR-3000 Data Acquisition System. Processing of data will be completed on a PC with the RADAN software package that includes an interactive 3D module (www.geophysical.com/software.htm). Antennae are frequency specific and depth of penetration of GPR surveys are a function of frequency, which range from 25 to 1000 MHz for the GPR method; the lower the frequency, the deeper the penetration (Figure 3; Note: antenna frequencies of 100 MHz and lower are regulated by the FCC and not available to the PI’s). Penetration is also very much a function of the conductivity of the geologic materials surveyed. For example, saline or sodic soils and wet clays are highly conductive and can limit penetration depths to the uppermost meter or less. Soil suitability maps for the conterminous United States are available online from the National Resources Conservation Service and show that much of Vermont is amenable to GPR studies (soils.usda.gov/survey/geography/maps/GPR/index.html).

Figure 2. Contoured depth to bedrock map for the NU Cemetery.

Examples of GPR applications relevant to projects that undergraduates at UVM and NU might undertake include: 1) groundwater and hydrologic systems (e.g., de Menenzes Travassos and de Tarso Luiz Menenzes, 2004; Doolittle et al., 2006a, 2006b); 2) bedrock fractures (e.g. de

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Menenzes Travassos and de Tarso Luiz Menenzes, 2004; Kadioglu, 2008; Luodes, 2008; Porsani et al., 2006); 3) slope stability (e.g., Ganerod et al., 2008; Saas and Krautblatter, 2007); 4) clastic or carbonate sedimentation and stratigraphy (e.g., Cagnoli and Russell, 2000; Froese et al., 2005; Kadioglu, 2008; Nielsen & Vindum, 2003; Smith and Jol, 1997; Staggs et al. 2003); and 5) fault studies (e.g., Chow et al., 2001; McClymont et al., 2008).

Multi-frequency electromagnetic conductivity meter. Electromagnetic conductivity meters detect variations in subsurface conductivity. Alternating magnetic fields produced by a transmitter at specific frequencies induce a small amount of current to flow through materials in the subsurface, which in turn produces a secondary magnetic field that can be detected by a receiver. Our proposed profiler system, the Profiler EMP-400 from Geophysical Survey Systems, Inc. has a fixed separation (4 feet) between transmitter and receiver and can be deployed in either the vertical or horizontal dipole mode, simultaneously measuring up to three frequencies between 1000–16,000 Hz. The output can either be apparent conductivity in mS/m or the mutual coupling ratio (Q) in ppm for both the in-phase and quadrature components. The unit is integrated with a wireless PDA Data Logger with12-Channel WAAS GPS so that spatial data is collected in concert with conductivity data and both can be displayed in real time. Files are structured in Excel spreadsheet format (ASCII text file) for simple download to a PC for further evaluation utilizing third party software (e.g., Surfer from Golden Software).

We highlight a recent investigation by the Vermont Geological Survey as an example of an application for the EMP-400 Profiler unit (Figure 4). Domestic water wells in East Montpelier, Vermont were found to be contaminated with high nitrate levels. Two possible sources of nitrate contamination included: 1) neighboring agricultural fields of the Fairmont Farm fertilized with manure comprised a non-point source, and 2) a bedrock ravine adjacent to the agricultural fields that had been filled with liquid manure comprised a point source. Monitoring wells were installed and revealed some general information about directions subsurface flow, but ultimately it was the employment of an EM conductivity meter that revealed how the two sources were interacting.

Figure 3. Skin depths for different frequencies and resistivities modified after Mussett and Khan (2000). Electromagnetic (EM) waves are progressively attenuated and decrease exponentially with depth as they travel through a conductor. Skin depth refers to the depth at which the amplitude of EM waves is reduced by a factor of 1/e (approximately 1/3). Lower frequency waves will penetrate deeper in any given geologic material than higher frequency waves. Likewise, EM waves will penetrate deeper in geologic materials with higher resistivity. EM Profiler range shown is specific to the EMP-400 Profiler Instrument quoted in this proposal. 200 and 400 MHz GPR antennae, also quoted, are indicated.

Several studies have shown the benefits of integrated electromagnetic conductivity and

GPR field studies (e.g., Yoder et al., 2001; Inman et al., 2002; Witten, 2003; Stepler et al., 2004) including the fact that preliminary electromagnetic conductivity surveys can be extremely

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beneficial to planning GPR surveys because the depth of penetration of the GPR method can be extremely limited when highly conductive materials are present. In other words, regions of high conductivity can be identified relatively quickly with preliminary electromagnetic surveys and proper locations for the GPR grid to maximize depth resolution identified.

Figure 4. Results of a geologic investigation and an electromagnetic conductivity survey of Fairmont Farm, East Montpelier, Vermont. Red dots = domestic bedrock wells; green dots = bedrock outcrops; pink stars and blue triangles = monitoring wells; purple upside down triangles = locations where fluorescent dye was introduced for flowpath tracing; red arrows = flow vectors deduced from well tests. The non-point source for nitrate contamination is the light colored field on the left hand side. The point source for nitrate contamination is the bedrock ravine in the lower center part of the image (circled in brown). The yellow rectangle represents the area that was surveyed with an electromagnetic conductivity meter (results shown in lower image). The green lines represent the three regions of high conductivity imaged and azimuths correspond to regional trends in bedding/foliation and fractures. An azimuth of 024 corresponds to bedding/foliation, while azimuths of 087 and 311 correspond to fractures. Wells 1065, 1073 and 1074 saw the most dramatic change in nitrate levels following remediation efforts and is believed to reflect the fact that the paths controlled by subsurface foliation and fracture networks were piping nitrates from both point and non-point sources toward the aquifer tapped by the wells. Figures courtesy of Vermont Geological Survey.

Submeter accuracy GPS. Although standard code-phase GPS with WAAS corrections

may be adequate for some of our geophysical surveying needs, the sub-meter GPS with

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external antenna will give students the capability of accurately and rapidly collecting data on tightly spaced grids and provide a level of accuracy sufficient for horizontal control of our gravity survey points. We will accomplish this high accuracy by post-processing of the GPS data. The Vermont Agency of Transportation operates a network of 15 continuously operated reference stations (VT CORS). These are situated such that any point in the state is within about 50 km of a reference station. Students can access this data at the Vermont Agency of Transportation website (http://vcap.aot.state.vt.us/CORS/vtcors.htm).

Obtaining vertical control for gravity stations has long been a difficult process. Although the vertical accuracy to be expected with the Trimble GeoXT and Hurricane antenna is likely to be greater than one meter and this is not adequate for gravity corrections, LIDAR elevation data can be utilized to help solve this problem. LIDAR is increasingly available in Vermont and we plan to use the sub-meter GPS for horizontal location of gravity stations in areas where we have LIDAR coverage. With sub-meter GPS supplying the horizontal location and LIDAR supplying the vertical position, we will be able to obtain sub-meter vertical accuracy for gravity surveys.

Equipment maintenance. NU’s existing geophysical equipment was purchased in 1985 with funds from a NSF DUE grant (award # 8650939) and has successfully been maintained and used in undergraduate teaching and research for over 20 years. This proposal represents the first major upgrade (hardware and software) following that award. Likewise, we anticipate a long lifetime out of the exploration geophysical equipment proposed for acquisition here. The ground-penetrating radar system and the electromagnetic profiling systems include rugged, field-tested components including military-spec cabling and connectors. Neither system requires factory recalibration or maintenance. The bases of both 200 and 400 MHz antennas have skid plates that occasionally need replacement (estimated after several years of use and costing roughly $100). Computer and software upgrades will be the chief cost over the nearer term and these will be planned for and covered using department funds (see letter of support). Expected Measurable Outcomes and Assessment Plan

This grant seeks funds to acquire instrumentation for field-based courses in geophysics, a new addition to the Geology curriculum offered at UVM with potential to attract students from other majors such as Anthropology and Geography, as well as to diversify undergraduate research opportunities at both UVM and NU. Student learning objectives for the new Geophysics curriculum at UVM include the following abilities of students at the end of the course: 1) apply geophysical theory to the study of both deep Earth and near surface environments; 2) design and execute geophysical experiments involving a variety of instrumentation; 3) interpret the results of geophysical experiments, including analysis of the limitations of the data; 4) synthesize geophysical and geological data and evaluate non-unique solutions; and 5) communicate research findings to the lay public. We hypothesize that acquiring this instrumentation to mount project-based field studies in geophysics will: 1) improve students’ 3D visualization; 2) improve cognitive activities in students that are critical to developing their inquiry skills, such as experiment design, and developing and testing alternative explanations for data sets, and synthesizing results obtained from different instrumentation; and 3) determine if university-agency collaborations effectively generate synergies to produce scientifically relevant research opportunities for students, while providing meaningful scientific data for state and local agencies. We will assess the success of the collaborative approach as well as student learning objectives using several approaches.

The UVM Center for Teaching and Learning (CTL) will oversee the assessment process (letter of support attached). Formative assessment techniques, such as concept maps (Zeilik et al., 1997), will be used in the early stages of field project development to assess each student’s understanding of the “big picture” problem at hand. Field projects themselves will be assessed using project reports (oral and written) that mimic those used by the environmental business community. We will specifically assess improvements in students’ 3D and critical thinking using

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a modification of pre-class knowledge surveys (i.e., pre-course “concept inventory tests”). Instead of multiple question tests (e.g. Reynolds, 2004), we will “flag” specific exercises in the prerequisite Field Geology class at UVM to serve as benchmarks identifying levels of student understanding regarding 3D thinking such as projecting surface geology to the subsurface. The flagged exercises will be coded by CTL. The same exercise will be given to students at the end of the Introduction to Exploration Geophysics class, returned to the CTL for coding so that a geology faculty member unaffiliated with the grant (UVM Geology faculty member Professor Charlotte Mehrtens) can rate student understanding of all responses as “naïve, developing, or accomplished” (Figure 5) without knowledge of student identity or course performance. CTL will collate and report results. At NU, where the geophysics instrumentation will be used in the introductory field methods class, an appropriate pre-class knowledge survey will be administered at the beginning of the class, coded by the CTL, and results compared to coded responses at the end of the semester. Over the past 10 years, student participation in undergraduate research at UVM has fluctuated widely, but averages 5 to 6 per year. We believe that an increase of at least 10% (one more student per year) will be significant over time. At NU, where undergraduate research is required for all Seniors, engagement in summer research programs now averages 2–3 students per year and we anticipate an increase to 4–6 students per year over the course of the grant. We will assess our success at increasing student participation in undergraduate research at both institutions by tracking the numbers and topics of research projects. Finally, we will qualitatively assess our success of the higher education-state collaboration through annual meetings between the P.I.s and the State Geologist to ascertain the degree to which we have produced quality subsurface geologic information in critical areas of interest to the Vermont Geological Survey.

Naïve Developing Accomplished

General Information

illustrations lack basic information

illustrations include some basic information

but are incomplete

illustrations have captions, scale, legend, units are

labeled

Vocabulary use of non-technical terms

such as: "goes away", "disappears", "changes to"

vocabulary is a mix between non-technical and technical geologic

terms

use of technical terms such as: "pinches out", "transitions laterally", "facies", "truncates"

Geologic Content

only most basic relationships and characteristics are

recognized (e.g. color, layering)

recognizes basic relationships and

characteristics (rock types inferred, notes dip

of bedding/foliation)

rock types are distinguished, cross-

cutting relationships noted, orientation of faults, folds,

etc. are described

3D Interpretation

no attempt or unable to project relationships to

depth

major features such as faults projected to depth

reasonable interpretation of features such as faults

and folds at depth; transitions observed at

surface taken into account in subsurface

Hypotheses poorly formulated with no criteria for testing

one or more hypotheses presented but poorly developed criteria for

testing

multiple hypotheses presented with criteria for

testing

Figure 5: Sample evaluation rubric for assessment exercises. Dissemination Plan

The outcomes of the approaches outlined in this proposal will be disseminated in a variety of venues, including technical sessions (Geoscience Education) at 2012 GSA annual meeting, articles in Journal of Geoscience Education, and through NSF’s Project Information

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Resource System and/or National Science Digital Library. What is innovative about this proposal is the hypothesis that the collaboration of institutions of higher education and the Vermont Geological Survey and UVM’s Consulting Archaeology Program will result in greater student engagement in real world problems at the same time it provides these agencies with valuable subsurface data. Results of this work will also be published in technical reports issued by the Vermont Geological Survey and the Consulting Archaeology Program, and in peer-reviewed publications. Laurence Becker, the Vermont State Geologist is Chair of the Association of American State Geologists Earth Science Education Committee. We anticipate presenting the results of this project to this organization’s annual meeting, which we hope will facilitate broader application of these types of collaborations (see attached letter of support). Role of the Principal Investigators and Senior Personnel

Laura Webb, Assistant Professor, UVM. Webb will develop the new Introduction to Exploration Geophysics course at UVM, to be fully developed and taught with the field methods component in the fall of 2011. In the first year of the project she will oversee acquisition of items related to the UVM budget and attend training at the Geophysical Survey Systems, Inc. for both the GPR and EM systems. She will work with Springston and Westerman in the fall of 2010 when the new geophysical instrumentation is used for the first time in the Field Geology and Exploration Geophysics course at NU. Webb will also supervise undergraduate research that utilizes the new instrumentation.

Keith Klepeis, Professor, UVM. Klepeis teaches the Field Geology course at UVM each fall semester and will administer the flagged exercises used in assessment. Klepeis will also help supervise undergraduate research undergraduate research in conjunction with the Vermont Geological Survey that utilizes the new instrumentation.

Dave Westerman, Professor, Norwich University. Westerman will develop the modification to the Field Geology and Exploration Geophysics course at NU and supervise undergraduate research that utilizes the new geophysical instrumentation.

George Springston, Research Associate, Norwich University. Springston will act as the main liaison between NU, UVM, and the Vermont Geological Survey, and will attend training at the Geophysical Survey Systems, Inc. for both the GPR and EM systems. He will also work with Westerman on new Field Geology and Exploration Geophysics course at NU, and with the Webb during the fall of 2011 when NU instrumentation is being utilized in the new Geophysics course at UVM. Springston will help supervise undergraduate research that utilizes the geophysical instrumentation in conjunction with the Vermont Geological Survey projects. Intellectual Merit The geophysical instruments proposed for acquisition are strategically chosen to increase curricular and research opportunities for undergraduate students to participate in geological investigations pertaining to real-world problems with geological, environmental and archaeological implications. The collaboration between UVM and NU has the benefits of: 1) the partnering of an early career faculty member developing new field-based curriculum in geophysics with established faculty and staff whose experience will serve as a resource as both institutions seek to improving STEM (science, technology, engineering, and mathematics) teaching and learning. 2) Partnering of public/private academic institutions with the Vermont State Geological Survey and the UVM Consulting Archaeology Program to provide opportunities for students to work on real-world problems relevant to citizens of the State of Vermont. And 3) because the main field-based courses that will utilize the equipment will be offered alternating years at UVM and NU, the cooperative sharing of key equipment will maximize its impact and efficient use.

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Broader Impacts This project supports the curriculum development efforts of an early career female faculty member at UVM and will improve STEM teaching and learning through the use of technology at both UVM and NU. New opportunities for undergraduate students in the form of group projects and individual research will be created. The results of these new student opportunities will have direct applications to environmental issues, such as groundwater resources in the State of Vermont, and thus provide a powerful mechanism for STEM-related educational outreach to the public. Results from Prior NSF Support

Results from prior support for L. Webb. 1) Acquisition of an Excimer Laser System for Syracuse University Noble Gas Isotope Research Laboratory, (EAR-0345822, $77,340; 07/15/04-06/30/07). This grant, cost-shared by Syracuse University, funded the purchase an excimer laser, permitting the measurement of argon isotopes within a textural context. The laser system will be used in studies that investigate the timing of fabric development in polymetamorphosed and/or multiply deformed rocks. The laser has also been used to investigate diffusion profiles in helium-doped crystals with colleagues from Rensselaer Polytechnic Institute. 2) Collaborative Research: Strike-Slip History of the East Gobi Fault Zone, Mongolia: Modes of Intraplate Deformation, Sedimentary Basin Evolution, and Regional Fault Linkages, (EAR-0537165 & EAR-0929902, $267,223; 03/01/06-03/31/10). This project employs a multidisciplinary approach to constrain the timing, kinematics, and amount of offset associated with two sinistral strike-slip phases along the East Gobi Fault Zone: Late Triassic ductile shear and Cenozoic brittle faulting. The project is in collaboration with C. Johnson (University of Utah). This work will result in one PhD thesis (J. Taylor, Syracuse Univ.), one MS thesis (M. Stypula, Univ. of Vermont), and the involvement of two undergraduate students in research (I. Semple, Syracuse Univ.; G. Hagen-Peter, Univ. of Vermont). To date, this research has resulted in ten co-authored published abstracts: Webb et al. (2006, 2007), Webb and Johnson (2006), Taylor et al. (2007, 2008), Heumann et al (2007, 2008), Semple et al. (2007), and Johnson et al. (2006); the first of several manuscripts is near submission.

Results from prior support for K. Klepeis. 1) Lower crustal deformation and vertical coupling and decoupling in the continental lithosphere during late orogenic extension (EAR-0337111, $224,327; 01/01/04-12/31/06). Mesozoic granulite and eclogite facies exposures in Fiordland, New Zealand were used to determine how extensional strains were transferred vertically through a rheologically evolving crustal column. This project generated 4 MSc. theses (Marcotte, 2004; King, 2005; Judge, 2006; Betka, 2007); 2 undergraduate projects (Zimmerman, 2005; 2006); contributed to 2 PhD theses (Flowers, 2005; De Paoli, 2010); and 11 peer-reviewed publications (Hollis et al., 2004; Klepeis et al., 2004; Schröter et al., 2004; Klepeis & Clarke, 2004; Stevenson et al., 2005; Flowers et al., 2005; Clarke et al., 2005; Marcotte et al., 2005; Klepeis et al., 2007; King et al., 2008; Klepeis & King, 2010) with another paper in review (De Paoli et al., submitted). 2) Lithospheric weakening, deep crustal flow and the initiation of orogenesis at a noncollisional convergent margin in the Andes (EAR-063594, $293,063; 09/01/07-09/01/10). In the first 1.5 years of this project we mapped poorly known regions of the Darwin metamorphic complex in southernmost Patagonia (55°S latitude). This complex contains the largest exposure of Mesozoic, moderate to high-P (8-10 kbar) metamorphic rocks in the Andes south of Ecuador. We have shown that these high-P rocks constitute a mid-lower crustal wedge of metamorphic basement and have obtained 10 new ages (U-Pb on zircon) that date the time of deformation and ophiolite obduction in a retroarc setting. The project is in collaboration with colleagues from Chile (Hervé) and Australia (Fanning). We already have 6 abstracts (Klepeis et al., 2008; Klepeis et al., 2007; Álvarez et al., 2007; Hervé et al., 2007; Fanning et al., 2007; Pankhurst, et al., 2007) and one submitted paper (Hervé et al., 2009) and two others nearing the submission stage.