Barbara J. Tewksbury

Teaching Methods in Undergraduate Geoscience Courses: Results of the 2004 on the Cutting Edge Survey of U.S. Faculty

A survey of U.S. geoscience faculty provides an integrated look at the geoscience courses currently being taught and the teaching methods that are used in these courses. The survey data indicate that there is a wide array of offerings both at the introductory level and for majors and thus no standard geoscience curriculum. While teaching methods remain dominated by lecture, most faculty use a range of more interactive methods. Most students are asked to solve problems including quantitative ones as part of their courses although relatively few explore problems of their own choosing. Writing and reading in the primary literature are used extensively in courses of all sizes at both the introductory level and in courses for majors. Strategies and tools for assessing student learning are strongly dependent on class size; however, students are more likely to be assessed through problem sets, oral presentations or papers in courses for majors. There is no question that research on learning and the resulting recommendations for best classroom practice that have emerged over the past decade have had an impact on geosciences classes. On the other hand, there is room for growth. Our data suggest that most faculty are still using these techniques infrequently. These results strongly support the continued offering of professional development activities that both bring new ideas to faculty and address the practicalities of widespread implementation of these techniques.

Polygonal faults in chalk: Insights from extensive exposures of the Khoman Formation, Western Desert, Egypt

Although polygonal fault systems and related features are common in fine-grained sediments in modern submarine basins and have been studied in basins worldwide using three-dimensional (3-D) seismic data, extensive on-land exposures have remained elusive. We report here on the discovery of a polygonal fault system occurring in nearly continuous surface exposure over ∼900 km 2 in chalk of the Cretaceous Khoman Formation near Farafra Oasis, Egypt. Field exposures reveal polygon boundaries defined by clusters of dozens of normal faults with strongly grooved fault surfaces and coarse calcite veins along faults with evidence for multiple fluid flow events. Geometric patterns and fault intersections reveal that mechanically interacting normal faults with multiple orientations were active contemporaneously in a horizontal strain field that was essentially isotropic and extensional. We interpret the very steep dips (∼80°) to reflect fault initiation in response to elevated pore fluid pressures. In the uppermost part of the Khoman Formation, a terrain of isolated circular structures displaying shallow inward dips overlies the polygonal fault network. The spatial relationship to the underlying faults is consistent with these small circular basins having formed as fluid escape structures as the polygonal fault system evolved. Outcrops in the Khoman Formation provide an unprecedented look into the 3-D geometry of a polygonal fault system, providing context for the analysis of analogous systems in marine basins and other on-land exposures.

Developing and Applying a Set of Earth Science Literacy Principles

ABSTRACT The 21st century will be defined by challenges such as understanding and preparing for climate change and ensuring the availability of resources such as water and energy, which are issues deeply rooted in Earth science. Understanding Earth science concepts is critical for humanity to successfully respond to these challenges and thrive in the decades to come. As part of efforts to address this, a new program called the Earth Science Literacy Initiative (ESLI) was formed in 2008 with funding from the National Science Foundation (NSF). Its task was to create a succinct document outlining what citizens should know about Earth science. This document, called the Earth Science Literacy Principles (ESLPs), has applications in both public and private arenas. For example, the ESLPs have been used to define the core ideas of both a middle school textbook program and a new set of K–12 science education standards. The ESLPs, which are founded in a broad representation of the geoscience community, based upon current research, and endorsed by major government, industry, and academic geoscience organizations, represent an effort by the Earth science community to create a coherent and fundamental set of big ideas and supporting concepts that represent our fields.

Specific Strategies for Using the “Jigsaw” Technique for Working in Groups in Non-Lecture-Based Courses

The “jigsaw” technique is a versatile strategy that can be used in many different ways to increase the involvement of students in their own learning and to create an effective learning environment in a course that de-emphasizes lecture. Teams of students are assigned to investigate different aspects of the same problem or issue. Each team might, for example, analyze a different but related data set or read an article on different aspects or viewpoints on the same topic. Once each team member thoroughly understands his/her teams aspect of the problem, new groups are formed, with at least one representative from each original team. Each individual then explains her/his teams aspect of the problem to the new group. In this way, every student learns every aspect of the problem. Each group then uses the combined information to evaluate a summary issue. The technique works most successfully if 1) there are different but overlapping assignments for different teams, 2) individual students prepare before teams m...

Improving undergraduate STEM education: The efficacy of discipline-based professional development

Effective teaching practices are more common in courses taught by faculty who spend time learning about teaching. We sought to determine whether instructional practices used by undergraduate faculty in the geosciences have shifted from traditional teacher-centered lecture toward student-engaged teaching practices and to evaluate whether the national professional development program On the Cutting Edge (hereinafter Cutting Edge) has been a contributing factor in this change. We surveyed geoscience faculty across the United States in 2004, 2009, and 2012 and asked about teaching practices as well as levels of engagement in education research, scientific research, and professional development related to teaching. We tested these self-reported survey results with direct observations of teaching using the Reformed Teaching Observation Protocol, and we conducted interviews to understand what aspects of Cutting Edge have supported change. Survey data show that teaching strategies involving active learning have become more common, that these practices are concentrated in faculty who invest in learning about teaching, and that faculty investment in learning about teaching has increased. Regression analysis shows that, after controlling for other key influences, faculty who have participated in Cutting Edge programs and who regularly use resources on the Cutting Edge website are statistically more likely to use active learning teaching strategies. Cutting Edge participants also report that learning about teaching, the availability of teaching resources, and interactions with peers have supported changes in their teaching practice. Our data suggest that even one-time participation in a workshop with peers can lead to improved teaching by supporting a combination of affective and cognitive learning outcomes.

Connecting the Geology of Africa with the Prehistoric, Historical, Political, and Economic Evolution of the Continent as a Strategy for Teaching Introductory Geology and Attracting Minority Students to Geology

An innovative introductory geology course entitled The Geology and Development of Modern Africa was developed and offered at Hamilton College for the first time during 1994–95. The aims of the course are three-fold: 1) to attract African American students to take geology, 2) to help students draw connections between geology and non-science topics with which they are more familiar, and 3) to teach students rigorous geology in a setting that minimizes lecture and emphasizes hands-on investigative activities, self and group learning, and peer teaching. The course is structured around a series of geologic topics that have direct relevance to particular prehistoric, historical, political, or economic issues in Africa. The course emphasizes how an understanding of the geologic context allows a deeper understanding of the reasons for the prehistoric, historical, political, and economic evolution of Africa. In this course, students delve deeply into a limited number of topics: past and present fluvial processes o...

Teaching Without Exams – The Challenges and Benefits

The traditional way of motivating students and assessing whether they learn is to give examinations. Successful teaching without exams requires the use of alternative structures that are at least as effective for both motivation and assessment. Three of the courses that I teach regularly have no exams, and I rely on written and oral assignments both as learning tools and as a means to motivate students and assess their work. Each week, the students in these classes prepare one or two written or oral assignments in which they integrate data and readings, make comparisons with what they have learned previously, take positions on issues, and so on. Written assignments typically form the basis for group or class discussion or oral presentations. Frequent written and oral assignments accomplish the following. First, the assignments require that students process information in ways that are more significant and sophisticated than is possible on conventional exams. Second, students are forced to engage the mater...

Conjugate crenulation cleavages in the Uncompahgre Formation, Needle Mountains, Colorado

Abstract Multiply deformed metasediments of the Proterozoic Uncompahgre Formation contain a well-developed conjugate set of crenulation cleavages and related folds. Conjugate character is indicated by the presence of conjugate folds and crenulations, synchronous cleavage development, lack of consistency in sense of overprinting where overprinting exists, and bimodal attitude distribution on πS2 diagrams. Despite the overall conjugate character of the folds and cleavages, most outcrops exhibit only one of the two possible sets. Attitudes of fold hinges and intersection lineations suggest that these conjugate structures formed late in the second phase of deformation, after extensive D1 transposition and after D2 macroscopic folds were well-developed and cut by fold-related thrusts. Although considerable controversy exists regarding whether non-conjugate sets of crenulation cleavages develop parallel to the XY plane of the strain ellipsoid or not, it is clear that conjugate crenulation cleavages must develop at an oblique angle to the XY plane. Although individual outcrops may develop one member of a conjugate set to the exclusion of the other, mechanical and geometric constraints necessary for conjugate cleavage development appear to be such that it is extremely unlikely that only one member of a conjugate set would develop over an entire region to the total exclusion of its conjugate pair. Although similar in appearance, conjugate and non-conjugate crenulation cleavages appear to be two different species, one forming at a substantial oblique angle to the XY plane, the other probably forming parallel or nearly parallel to it.

Beyond Hazards and Disasters--Teaching Students Geoscience by Probing the Underlying Influence of Geology on Human Events.

An introductory geology course is described that both introduces geologic principles and explores the ways in which geology can have an underlying influence on human events that is much deeper and more subtle than the distribution of resource wealth and geologic hazards. The course aims primarily to help students draw connections between geology and the non-science topics with which many of them are more familiar. It revolves around a series of geologic topics that have direct relevance to particular pre-historic, historical, political, or economic issues in Africa. It is also designed to teach students rigorous geology in a setting that minimizes lecture and emphasizes instead hands-on investigative activities, self- and peer-teaching, and group-learning. The course serves as a model for designing similar courses.

Using the Geology of the Indonesian Region as a Basis for Introductory Geology Labs

Rather than focusing on teaching students to classify and identify, labs in my introductory geology course “Planet Earth” are woven around investigation of a tectonic/geologic map of the Indonesian region published by the U.S. Geological Survey. From the outset, students know that their goal in lab will be to analyze the geology of three separate areas of the region, formulate hypotheses for the tectonic evolution of each area, test and revise their hypotheses, marshall evidence to defend their views, and evaluate the uncertainties in their models. This is a tall order in an area as complex as the southwest Pacific, and individual lab exercises help students apply what they have learned in lecture to solve specific problems in the region. By the end of the course, students have gained enough experience both in the geology of the Indonesian region and in asking and answering geologic questions that they can quite successfully analyze three technically significant portions of the map that they have not inve...