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Spatial skills are embedded in all aspects of the geosciences. The teaching and learning of spatial skills has been a challenging, but vital, endeavor. To support student learning of spatial skills in undergraduate courses, we designed scaffolds for spatially dependent content in a mid-level geoscience course using playdough to allow students to model and manipulate geologic structures and processes. Using a semester-long geology course as a case study, we explore the ways in which students reported playdough supported their learning of geoscience content during the course. Students found the playdough most helpful for visualizing geologic structures, such as faults and domes, which students were then able to encode into their long-term memories, or "mental libraries," for application to new contexts on assessments later. The playdough was more helpful at the start of the course when students were grappling with introductory course content and skills. Later in the course, the need for the playdough as a scaffold faded, as intended. Most students eventually sought new scaffolds, such as three-dimensional block models, which illustrate more complex and sophisticated structures and processes. Therefore, we see playdough as a useful scaffold for students in the early stages of spatial and geologic skill development as it aids students in developing both sets of skills. It is easy to utilize, inexpensive, portable, widely available, and familiar to most students.

Spatial visualization is an essential prerequisite for understanding geological features at all scales, such as the atomic structures of minerals, the geometry of a complex fault system, or the architecture of sedimentary deposits. Undergraduate geoscience majors bring a range of spatial skill levels to upper-level courses. Fortunately, spatial thinking improves with practice, and students benefit from intentional training. Several promising teaching strategies have emerged from recent cognitive science research into spatial thinking: gesturing, predictive sketching, and comparison, including analogy and alignment. Geoscience educators have traditionally incorporated many of these tools in their teaching, though not always consciously, intentionally, and in the most effective ways. Our research team, composed of geoscientists and cognitive psychologists, has collaborated to develop curricular materials for mineralogy, structural geology, and sedimentology and stratigraphy courses that incorporate these strategies intentionally and purposefully, supporting student understanding of the spatially challenging concepts and skills in these courses. Collectively, these two dozen learning activities comprise the Spatial Thinking Workbook (http://serc.carleton.edu/spatialworkbook/index.html). Pre- to posttest gains on a suite of assessment instruments, as well as embedded assessments, show that these curricular materials boost students' spatial thinking skills and strengthen their ability to solve geological problems with a spatial component.

Spatial thinking skills are critical to success in many subdisciplines of the geosciences. We tested students' spatial skills in geoscience courses at three institutions (a public research university, a comprehensive university, and a liberal arts college, all in the midwest) over a two-year period. We administered standard psychometric tests of spatial skills to students in introductory geology, mineralogy, sedimentology and stratigraphy, hydrogeology, structural geology, and tectonics courses. In addition, in some courses we administered a related spatial skills test with geoscience content. In both introductory and upper level undergraduate geology courses, students' skills vary enormously as measured by several spatial thinking instruments. Additionally, students' spatial skills generally improve only slightly during one academic term, in both introductory and advanced geoscience classes. More unexpectedly, while there was a tendency for high-performing students to be adept at multiple spatial skills, many individual students showed strong performance on tests of one spatial skill (e.g., rotation) but not on others (e.g., penetrative thinking). This result supports the contention that spatial problem solving requires a suite of spatial skills, and no single test is a good predictor of "spatial thinking."

Geoscience instructors and textbooks rely on analogy for teaching students a wide range of content, from the most basic concepts to highly complicated systems. The goal of this paper is to connect educational and cognitive science research on analogical thinking with issues of geoscience instruction. Analogies convey that the same basic relationships hold in two different examples. In cognitive science, "analogical comparison" is understood as the process by which a person processes an analogy. We use a cognitive framework for analogy to discuss what makes an effective analogy, the various forms of analogical comparison used in instruction, and the ways that analogical thinking can be supported. Challenges and limitations in using analogy are also discussed, along with suggestions about how these limitations can be addressed to better guide instruction. We end with recommendations about the use of analogy for instruction, and for future research on analogy as it relates to geoscience learning.

Understanding and communicating uncertainty is a key skill needed in the practice of science. However, there has been little research on the instruction of uncertainty in undergraduate science education. Our team designed a module within an online geoscience field course which focused on explicit instruction around uncertainty and provided students with an uncertainty rating scale to record and communicate their uncertainty with a common language. Students then explored a complex, real-world geological problem about which expert scientists had previously made competing claims through geologic maps. Provided with data, expert uncertainty ratings, and the previous claims, students made new geologic maps of their own and presented arguments about their claims in written form. We analyzed these reports along with assessments of uncertainty. Most students explicitly requested geologists' uncertainty judgments in a post-course assessment when asked why scientists might differ in their conclusions and/or utilized the rating scale unprompted in their written arguments. Through the examination of both pre- and post-course assessments of uncertainty and students' course-based assessments, we argue that explicit instruction around uncertainty can be introduced during undergraduate coursework and could facilitate geoscience novices developing into practicing geoscientists. [ABSTRACT FROM AUTHOR]

Managing uncertainty is fundamental to geoscience practice, yet geoscience education generally does not incorporate explicit instruction on uncertainty. To the extent that students are exposed to scientific uncertainty, it is through in-person field experiences. Virtual field experiences - which rely on pictures, maps, and previously collected measurements - should therefore explicitly address uncertainty or risk losing this critical aspect of students' experience. In this paper we present a framework for teaching students to assess and communicate their uncertainty, which is grounded in best expert practices for conveying uncertainty and familiar terms-of-art in geology. The starting point of our framework is the recognition of uncertainty in both geologic data and models, the latter of which we use as an encompassing term to refer to potential geological processes and structures inferred on the basis of incomplete information. We present a concrete application of the framework to geological mapping and discuss how it could enhance student learning in both traditional in-person and virtual experiences. Our framework is extensible in that it can be applied to a variety of geologic features beyond those where uncertainty is traditionally assessed, and can also be applied to geological subdisciplines. [ABSTRACT FROM AUTHOR]

Structural geologists support their mind with tools, and these tools are increasingly computer based. The advent of Intelligent Systems will allow creation of research teams that combine the strengths of the human mind and computer processing to produce new research results. The efficacy of these approaches will require a solid grounding in cognitive science. Critical to this approach are databases, which are potentially transformative solely in their ability to allow access to data, in a primary form. Emerging more recently, however, is the concept of a dataguide, in which computer-aided analysis informs ongoing decisions about where and what data to collect. The creation of human and computer teams can expand the types of questions that can be addressed in structural geology and tectonics research, but it will take a community-based effort to understand the value of data to experts and how computers might aid an expert in the field. • Human-computer field research teams could combine the strengths of human minds and computer processing to transform research. • Databases can provide new types of data to experts in the field, to support new field workflows. • Dataguides can aid data collection decisions, but must combine geology, cognitive science, and computational science. [ABSTRACT FROM AUTHOR]

Capturing the nature of students' mental representations and how they change with learning is a primary goal in science education research. This can be challenging in spatially intense domains, such as geoscience, architecture, and engineering. In this research, we test whether sketching can be used to gauge level of expertise in geoscience, using new technology designed to facilitate this process. We asked participants with differing levels of geoscience experience to copy two kinds of geoscience images-photographs of rock formations and causal diagrams. To permit studying the process of sketching as well as the structure and content of the sketches, we used the CogSketch system (Forbus et al. , Topics in Cognitive Science 3:648-666) to record the time course of sketching and analyze the sketches themselves. Relative to novices, geoscience students included more geological structures and relational symbols in their sketches of geoscience materials and were more likely to construct their sketches in a sequence consistent with the order of causal events. These differences appear to stem from differences in domain knowledge, because they did not show up in participants' sketches of materials from other fields. The findings and methods of this research suggest new ways to promote and assess science learning, which are well suited to the visual-spatial demands of many domains. [ABSTRACT FROM AUTHOR]

The Rock Springs uplift of Wyoming and the Douglas Creek arch of Colorado are intrabasinal, Laramide-age basement uplifts within the Rocky Mountain foreland, and are currently separated by the east-west-trending Uinta Mountains. The geometry, timing, and progressive development of these uplifts were investigated using a combined geophysical and geological approach. New gravity surveys were combined with existing regional data to provide a regional Bouguer gravity anomaly map of these two uplifts and the intervening Uinta uplift. The gravity data show a distinct and continuous north south-striking gravity high along the trend of the two uplifts that crosses the east-west-trending Uinta uplift. The relatively constant amplitude (∼40 mGal) of the gravity anomaly indicates that the inferred basement relief is similar for both arches (∼4 km). Sedimentation patterns indicate that the Rock Springs uplift and Douglas Creek arch formed simultaneously in the Late Cretaceous. The intrabasinal setting of the uplifts records aspects of foreland deformation that are overprinted or obscured in better-developed uplifts. On the local scale, neither the Rock Springs or Douglas Creek uplift apparently reactivates a pre-existing structure. On a regional scale, there is no change in structural style or timing of the two uplifts, despite their formation in different crustal provinces. The Rock Springs uplift occurs within the Archean Wyoming province north of the Cheyenne belt, whereas the Douglas Creek arch occurs in Proterozoic crust south of this boundary. Timing relations, available floor the basinal stratigraphy, indicate the uplifts were initiated as broad arches in the Late Cretaceous before developing into more concentrated uplifts. Thus, large-scale folding, and not reactivation of pre-existing structures, may be the primary control on the initial pattern of north- to northwest-trending foreland deformation. [ABSTRACT FROM AUTHOR]

The Johnson Granite Porphyry and the Silver Pass Porphyry are two late-stage porphyritic intrusions in the Cretaceous Sierra Nevada Batholith, California. Both intrusions are characterized by fine-grained textures, miarolitic cavities, pegmatite veins, and abundant xenoliths. Microstructures in the Johnson Granite Porphyry record magmatic flow. Magnetic fabrics in the Johnson Granite Porphyry, determined by anisotropy of magnetic susceptibility, show that the poles to magnetic foliations define a NNE-SSW girdle and magnetic lineations plunge shallowly to moderately to the WNW and ESE. A gravity survey and three-dimensional inversion indicate that the Johnson Granite Porphyry is shallow and tabular, extending to 1.5 km depth beneath the southwestern margin. A second gravity anomaly was delineated southeast of the Johnson Granite Porphyry, suggesting the intrusion continues to depth. The Silver Pass Porphyry is deformed by the dextral Rosy Finch shear zone and records a gradient of high- to low-temperature, solid-state fabrics. Field and magnetic foliations in the Silver Pass Porphyry are subvertical and lineations are shallowly plunging. We propose that regional shear zones controlled the emplacement of these intrusions. The Johnson Granite Porphyry was emplaced in a three-dimensional tension gash associated with the termination of the Bench Canyon shear zone. The Rosy Finch shear zone facilitated the emplacement of the Silver Pass Porphyry, probably as a tension fracture associated with the shear zone. The field observations and magnetic fabrics suggest that the Johnson Granite Porphyry may record an extrusive event, suggesting that volcanism may be related to deformation along active shear zones. [ABSTRACT FROM AUTHOR]

The article discusses the style and magnitude of off-fault deformation across the San Andreas fault system in central California using geologic and global positioning system (GPS) data. The system reportedly has a combined 12 kilometers of fault-parallel motions at 4-6 millimeters/year, and fault-perpendicular displacements at 3-5 millimeters/year alongside the creeping segment. The article suggests that the onset of an active fault creep over geologic time scales promoted fold growth.

Abstract: A detailed structural and rock magnetic study of the Trachyte Mesa intrusion and deformed sedimentary wall rocks, Henry Mountains, Utah, indicates that the intrusion grew vertically and horizontally by the accumulation of multiple horizontal magma sheets. 2–3cm thick shear zones recognized by intensely cataclasized plagioclase phenocrysts define the contact between sheets. Sheets have bulbous and / or steep frontal terminations and are flat on top. The foliation within the interior of the sheets, near the frontal termination, is subvertical. This steep foliation rotates into the subhorizontal shear zones near the top and bottom contacts and provides a magma flow direction indicator. Away from the frontal termination, the interior foliation rotates to become subhorizontal, similar to the fabric in recent analog experimental studies. Sheets are interpreted as being emplaced as plug flows. Both the field fabric and the rock magnetic data collected from 103 locations on the top of the intrusion and from 73 locations along a vertical cross section exposed in a stream gorge support a multi-stage model of intrusion growth. Emplacement begins as narrow magma channels and magma spreads radially outward from the channels to form sheets. Sheets are stacked upon one another and stop at the same lateral termination. The deformation of the sandstones at the margin of the intrusion, which are rotated upward from the margin to become the roof, is partitioned into layer parallel extension, shearing and layer-parallel shortening components. Bulk strain within the thickest sandstone layer indicates ∼20% thinning and microstructures indicate that the thinning was accommodated by grain-scale fracture-induced porosity collapse. Extension occurred as the layer was stretched over the margin of the rising intrusion. Shearing and layer-parallel shortening are a result of coupling with the underlying sheets as they advanced and accommodated through numerous faults parallel to bedding and at low angles to bedding. The deformation of thinner sedimentary layers is consistent with the sedimentary layering immediately in front of an advancing sheet being translated upward and over the top of the sheet as the hinge zone migrates with the front edge of the advancing sheet. [Copyright &y& Elsevier]