Using Layer-Cake Geology to Illustrate Structural Topographic Relationships

Most presently taught elementary physical and historical geology courses are inadequate as a foundation for advanced work and underaimed as environmental appreciation courses. It is recommended that physical geology be split into two courses: (1) an earth materials and interior course, and (2) geomorphology. It is further recommended that historical geology be split into (1) stratigraphy, and (2) paleontology.

Small-group cooperative-learning activities involving writing and/or oral presentations promote active learning in large lecture-based physical and historical geology courses. Groups include informal pairings of students for short discussions, writing peer-review groups of three to four students, and groups that work together throughout the semester on a variety of other projects. Writing assignments consist of ungraded in-class writing and graded short papers on a variety of geological topics. Oral presentations include debates, panel presentations, and skits. As students exchange ideas and work with one other in these activities, they are learning geology as well as improving their communication and collaboration skills. The learning communities that develop reduce the isolation many students feel in a large lecture class. To implement cooperative-learning, instructors should design activities that incorporate key elements of cooperative learning and are directly related to course objectives.

In the Earth sciences, the need for virtual field experiences (VFEs) is rapidly expanding. Not only has the pandemic increased the need for VFEs for use in Earth science courses that had to be adapted for remote teaching, but ongoing accessibility challenges also necessitate the development of alternative options to in-person field experiences. Towards that end, the EPICC (Eastern Pacific Invertebrate Communities of the Cenozoic) TCN (Thematic Collections Network) produced a series of virtual field experiences that explore various aspects of the Astoria Formation, a Miocene-aged unit located on the scenic central Oregon Coast. The Astoria Formation VFE can help educators and their students explore the ecological, geological, and scientific forces that shape the fossil record along the Oregon Coast. As one module of the project, the EPICC VFE outreach team created a taphonomy-focused VFE, From death and decay to database and display: the journey of a fossil through time and space, designed to explore the process by which dead organisms become fossils. Place-based learning features heavily in this module through extensive use of photographs of modern faunal assemblages from Oregon Coast tidepools and beaches as well as in situ fossils of similar ecosystems preserved in the Astoria Formation. To help instructors implement this activity, a student guide was developed with active learning activities that can be modified for either classroom or lab activities. This learning tool is appropriate for a wide range of educational levels, from instructors of grades 7-12 to college instruction, in which ready-made VFEs can be integrated into physical and historical geology courses.

Incorporating Writing into a General Educational Historical Geology Course

Although digitized, geological maps have poorly evolved since their inception and still retain the constraints imposed by printing: heterogeneity between map sheets, limited point data, and challenging update procedure that remains essentially nonexistent.The heterogeneity of geological maps also complicates their integration to Information System. Maps, based on rules and concepts that evolved over time, are no longer suited to the precision required by database structures. As concepts and models evolve in geology together with the scientific knowledge, the choice of the representation on the map also depends on the authors’ interpretations and the period of production. As a result, the mapped geological units reflect arbitrarily chosen characteristics of the rocks concerning either their protolith nature, their metamorphic characteristics or alteration transformations, considered as the most representative at the date of publication.In France, 1:50,000 scale geological maps provide a full territory coverage but do not escape these heterogeneity issues. To address this problem, the BRGM (French Geological Survey) has implemented the RGF program (Référentiel Géologique de la France), which aims to develop a methodology to overcome these limitations and propose an innovative approach to represent the geological knowledge. In this research program new data are acquired by PhD students allowing to improve geological knowledge and to produce updated and harmonized information on geological maps and boreholes.The tools developed and implemented over the past decade, based on the establishment of an Information System structured as a knowledge database called the Geological Reference System, now make it possible to offer a standardized representation of geological knowledge derived from traditional geological maps. This knowledge can be represented through different reference systems: lithostratigraphic unit, event (and thus the geological history), or domain and zone (e.g. lithotectonic units).Here, we present some of the results obtained from works conducted in the Alps, the Pyrenees, and the Montagne Noire, illustrating how this structuring of geological knowledge into reference system enables the creation of new maps tailored to the geological information one wishes to represent and, consequently, to the scientific and societal challenges at hand.

The main side of the W. Smith’s work — geological mapping — has been shown to be expressed in the series of maps, created by him, and first of all in the «Map of layers of England and Wales». The layers represented for Smith an object for mapping. His stratigraphic tables constitute the lists of stratons, systemized in the order of their bedding and origin. W. Smith discovered a general sequence of 34 layers ofEnglandandWales, in more detailes separated the deposits, substracted later in the Jurassic system. Fossils were considered by W. Smith as specific features of layers, being mapped. The very combination of the characteristics of talented geologist — map-maker und collector of fossils — allowed making the famous conclusion that every layer contained the fossils, typical exactly for it. W. Smith showed the specifics and continuity of paleontological characteristics of different layers, predefined the oportunity of their recognition and identification and designed the base for the development of biostratigraphic method and historical geology in a whole. The short biographic data for Smith has been given.

The Appalachian Project is an integrated five-week project for teaching about geologic maps. The project frees the student to work at his own pace either within or outside the laboratory. Each student receives a 15′ topographic quadrangle from the Valley and Ridge Province of Pennsylvania and a generalized geologic map of the area. The student identifies rocks and fossils encountered in the area and completes a stratigraphic column. He also completes a cross profile as the basis for a structure section that uses the generalized geologic map and topographic expression as guides. The student then constructs a more detailed geologic map of the quadrangle from the topographic expression of the rock units, and completes a report on the geologic history and economic prospects of the map area. Lafayette students have found this project to be the most valuable and interesting part of beginning geology.

The Platte River of south-central Nebraska was studied at three scales to place the river in its geological context and to trace its evolution through geologic time.At the largest scale the Elm Creek West and the Newark 7.5 minute quadrangles were mapped.These quadrangles are located just west and just east of Kearney and serve to illustrate the main geomorphic elements of the present Platte River Valley.The central elements of the quadrangles are the Platte River channels, islands, and bottomlands, which are fl anked by terraces that step up away from the river to the north and south.Significant other elements of the landscape are eolian sand and loess deposits.The geologic maps are supplemented by topographic profi les of the mapped terraces and graphical representations of subsurface units in test wells that occur within the quadrangles.An intermediate-scale study consisted of examining descriptions of well cuttings in a 17 county area in southcentral Nebraska, which includes the Platte River Valley, and building a database of information about sediment lithology and thickness.The wells penetrated a sequence of gravel, sand, silt, and clay beds from the ground surface to the top of the subsurface Tertiary Ogallala Group or Cretaceous formations.The sequence consists of Pliocene-, Pleistocene-, and Holocene-age strata that document the deposition of a veneer of alluvium by late Tertiary and Quaternary streams intermixed with and overlain by wind-blown loess.Various isopleth and structure maps illustrate the distribution and alluvial architecture of the sedimentary sequence, and support the interpretation of former positions of the Platte River.A regional-scale study consisted of documenting the geologic history

The Apollo mission data and samples have led to substantial advancements in our understanding of the Moon's geological history and processes. By incorporating new data from recent orbital missions, we systematically developed high-resolution geological maps for each Apollo landing site [e.g., 1-3]. The present study offers a detailed geological map for the Apollo 15 site. The Apollo 15 mission is noteworthy for its significant contributions to lunar geology, leading to substantial advancements in our understanding of volcanic activity, impact cratering, and the Moon's thermal evolution. Notwithstanding this progress, there are as yet unanswered scientific questions, which have been articulated as objectives for future missions such as the 500-day Hadley Max design reference mission (DRM) [4,5].The Apollo 15 landing site is located east of Hadley Rille on mare basalts that border the Imbrium basin. A thorough geological mapping of the area has revealed the presence of multiple units associated with the Imbrium basin, including its rim and ejecta deposits. These units have been classified based on their distinguishing topographic features. The surrounding area also contains plains deposits, such as Imbrian light plains, along with several mare basalt units of Eratosthenian and Imbrian age [6]. Materials from nearby craters, Autolycus and Aristillus [7,8], also contribute to the region's geological diversity. The linear rilles in proximity to the site have been mapped and categorized by age, employing a combination of stratigraphic relationships and morphological analysis.The newly developed maps have enhanced the measurement of crater-size frequency distributions (CSFDs), leading to improved N(1) values and a refined lunar cratering chronology [1-3]. Furthermore, the maps facilitate the identification of potential sample sources, thereby enhancing our comprehension of lunar stratigraphy [4,5]. Finally, these maps provide a fundamental framework for the evaluation of in-situ resources and the testing of novel technologies for forthcoming lunar missions [9].[1] Iqbal et al. (2019) Icarus 333, 528-547.[2] Iqbal et al. (2020) Icarus 352, 113991.[3] Iqbal et al. (2023) Icarus 407, 115732.[4] Daniti et al. (2024) LPSC 55, #1667.[5] Iqbal et al. (2024) LPSC 55, #1010.[6] Hiesinger et al. (2000) JGR 105, 29239-29275.[7] Hiesinger et al. (2000) JGR 105, 29239-29275.[8] Carr et al. (1971) USGS, I-723.[9] van der Bogert, et al. (2020) LPSC 51, #1876.

The South-Central Zone of the Damara Belt records a history of intense, complex deformation resulting from the collision between the Congo and Kalahari cratons during the Pan-African Orogeny. Structural models have typically focused on multiphase deformation with inherent changes in the stress field and, to a lesser degree, on progressive deformation driven by a stress field with less variation. One example of the latter is a model that separates the crust in the South-Central Zone into two structural domains, a higher crustal level and a deeper crustal level. This allows the existence of orthogonal fabric domains resulting from different strain fields within the same orogenic zone, without the need for major changes in the regional tectonic stress orientation.To date, geological maps and cross-sections have been used widely to graphically present the geological geometries of large areas in the Central Damara Belt. However, unlike 2D geological maps and sections, 3D models are more representative, providing additional insight to complex geometries and structural relationships. These complement and test traditional interpretations that often fail to account for the complexity and uncertainty of geological geometries.This study provides the first large-scale 3D lithostructural modelling of the deeper structural levels of the South-Central Zone of the Damara Belt, south and east of the Rossing Dome. The different rock units in this area display kinematic and geometric features that support large scale constrictional-type strain characteristics and top-to-the-southwest displacement. In addition to field mapping data, digital elevation models, satellite imagery and published geological maps were used to delineate the regional geometry of folded lithological units. The resulting 3D model contributes to a better understanding of the deformation of the deeper crust during the collision of continental fragments and the development of large-scale fold geometries.

Discrete proterozoic structural terranes associated with low- P, high- T metamorphism, Anmatjira Range, Arunta Inlier, central Australia: tectonic implications

About 150 samples of the plutonic rocks of the Raymond quadrangle were collected during geologic mapping. Of these, 137 were analyzed modally, 3 were analyzed chemically, and 4 were dated isotopically, 2 by the U-Pb method and 2 by the K-Ar method. In general, the different plutonic rocks show little internal compositional variation, but the hornblende-poor facies of the tonalite of Blue Canyon is zoned from more mafic in the margins to less mafic in the interior. The presence of subhedral to euhedral hornblende prisms and biotite books in the hornblende-rich facies of the tonalite of Blue Canyon is interpreted to indicate abundant H20 in the melt phase of the magma during crystallization, perhaps about 3 percent. However, a paucity of magnetite indicates low oxygen fugacity (FQ).

Predicting soil classes with parameters derived from relief and geologic materials in a sandstone region of the Vosges mountains (Northeastern France)

This book was written to fulfill a need of undergraduate geology students for a comprehensive text that covers field procedures, geologic interpretation of field relationships, use of digital equipment in the field, and map interpretation. Dr. Bevier, the author and an instructor for field geology courses, succeeds in this mission, providing a softbound, two-color book that is logically laid out, clearly written, and well illustrated. The writing is informal and sometimes humorous, and includes practical tips and real life examples. Although not as detailed nor as complete of a treatment as some classic texts, such as Geology in the Field (R. R. Compton, 1985), the book is more modern and accessible for beginning- to intermediate-level geology students, and I would recommend its purchase for students planning to attend a field geology course. Major sections of the book include an introduction to the importance of field geology, understanding geologic maps, base maps, tools and techniques in …

Introductory geology courses comprise an important part of a complete undergraduate education, and federal law stipulates that they must be accessible to all students. Mobility-impaired students, unfortunately, tend to avoid courses with required field trips because of real and perceived barriers to physical accessibility. Inexpensive evaluation, revision, and creation of accessible laboratories are pragmatic approaches that satisfy federal laws and open earth-science careers to talented students with mobility impairments.We have developed three new accessible field exercises for Stanford University's introductory geology course that improved the course rather than compromising its academic merit. In developing two new field trips, we set the following goals: 1) to locate potential sites relevant to material; 2) to eliminate obviously inaccessible locations; 3) to evaluate the remaining sites with, regard to accessibility criteria developed with advice of mobility-impaired students; 4) to test site accessibility with mobility-impaired persons; and 5) to advertise the new field trips. A third exercise creates a hypothetical field problem to teach principles of geologic mapping in an accessible setting.