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Field experiences are highly valued in geoscience education. However, logistical, financial, and accessibility challenges associated with fieldwork and rapid advancements in technology have all prompted geoscience educators to explore virtual field experiences (VFEs) as alternatives. Rigorous assessment of the effectiveness of VFEs has not kept pace with their implementation, but recent studies offer meaningful and actionable findings that can inform ongoing and future use of VFEs in geoscience education. We present a review of selected studies that address three significant aspects of this still-evolving modality. First, we examine current characterization and classification of VFEs. Second, we examine studies that evaluate the effectiveness of teaching with VFEs. Third, we extend this review to studies that compare VFEs with in-person field experiences (IPFEs). The studies we review demonstrate that VFEs are a valuable approach to teaching introductory geoscience content, even compared to IPFEs.▪Challenges associated with field geoscience education and improvements in technology have led geoscience educators to develop and implement virtual field experiences (VFEs) as teaching tools.▪VFEs are tested, practical, and effective alternatives to in-person field experiences in introductory geoscience education. 

Field learning is fundamental in geoscience, but cost, accessibility, and other constraints limit equal access to these experiences. As technological advances afford ever more immersive and student-centered virtual field experiences, they are likely to have a growing role across geoscience education. They also serve as an important tool for providing high-quality online instruction, whether to fully online degree students, students in hybrid in-person/remote programs, or students experiencing disruptions to in-person learning, such as during the COVID-19 pandemic. This mixed-methods study compared learning outcomes of an in-person (ipFT) and a virtual (iVFT) geoscience field trip to Grand Canyon National Park, each of which highlighted the Great Unconformity. Participants included introductory and advanced geology students. In the ipFT, students collectively explored the Canyon through the interpretive Trail of Time along the Canyon rim, guided by the course instructor. In the iVFT, students individually explored the Canyon and studied its geology at river level. 360° spherical images anchor the iVFTs and serve as a framework for programmed overlays that enable active learning and allow for adaptive feedback. We assessed cognitive and affective outcomes in both trips using common measures. Regression analysis showed the iVFT to be associated with significantly greater learning gains. The ipFT students had significantly higher positive affect scores pre-trip, reflecting their excitement for the trip. Overall, our results provide clear evidence that high-quality iVFTs can lead to better learning gains than ipFTs. Although field trips are employed for more than just content learning, this finding may encourage greater use of iVFTs in coursework. 

Abstract The Ediacaran Period (~635–539 Ma) is marked by the emergence and diversification of complex metazoans linked to ocean redox changes, but the processes and mechanism of the redox evolution in the Ediacaran ocean are intensely debated. Here we use mercury isotope compositions from multiple black shale sections of the Doushantuo Formation in South China to reconstruct Ediacaran oceanic redox conditions. Mercury isotopes show compelling evidence for recurrent and spatially dynamic photic zone euxinia (PZE) on the continental margin of South China during time intervals coincident with previously identified ocean oxygenation events. We suggest that PZE was driven by increased availability of sulfate and nutrients from a transiently oxygenated ocean, but PZE may have also initiated negative feedbacks that inhibited oxygen production by promoting anoxygenic photosynthesis and limiting the habitable space for eukaryotes, hence abating the long-term rise of oxygen and restricting the Ediacaran expansion of macroscopic oxygen-demanding animals. 

Surviving Extinction is an interactive, adaptive, digital learning experience through which students learn about the history of vertebrate evolution over the last 350 million years. This experience is self-contained, providing students with immediate feedback. It is designed to be used in a wide range of educational settings from junior high school (∼12 years old) to university level. Surviving Extinction ’s design draws on effective aspects of existing virtual field trip-based learning experiences. Most important among these is the capacity for students to learn through self-directed virtual explorations of simulated historical ecosystems and significant modern-day geologic field sites. Surviving Extinction also makes significant innovations beyond what has previously been done in this area, including extensive use of gamified elements such as collectibles and hidden locations. Additionally, it blends scientifically accurate animations with captured media via a user interface that presents an attractive, engaging, and immersive experience. Surviving Extinction has been field-tested with students at the undergraduate, high school, and pre-high school levels to assess how well it achieves the intended learning outcomes. In all settings we found significant gains pre- to post-activity on a knowledge survey with medium to large effect sizes. This evidence of learning is further supported with data from the gamified elements such as the number of locations discovered and total points earned. Surviving Extinction is freely available for use and detailed resources for educators are provided. It is appropriate for a range of undergraduate courses that cover the history of life on Earth, including ones from a biology, ecology, or geology perspective and courses for either majors or non-majors. Additionally, at the high school level, Surviving Extinction is directly appropriate to teaching adaptation, one of the disciplinary core ideas in the Next Generation Science Standards. Beyond providing this resource to the educational community, we hope that the design ideas demonstrated in Surviving Extinction will influence future development of interactive digital learning experiences. 

In the last few decades, the development of nontraditional isotope (e.g., Mo, Tl, U) measurements of redox sensitive metals provided information about the redox evolution of Earth’s oceans and atmosphere. Rhenium (Re) isotopes have the potential to fill a critical gap in the isotope proxy toolkit. Currently, there are proxies for ocean-basin-scale oxygenated and anoxic (0 uM O2 with no H2S) conditions, but there is not yet a proxy that can detect when large parts of the oceans were in a low-O2 but not anoxic condition, termed ‘suboxic’ (10 ≥ O2 > 0 uM). Detecting suboxic conditions is particularly important because some aerobic organisms can live in extremely low-O2 waters (down to ~10 nM O2; Stolper et al. 2010), and so it is of great interest to know when large parts of the ocean crossed from anoxic to suboxic conditions. Rhenium concentrations have been used as a paleoredox proxy to track suboxic and anoxic marine redox conditions locally, but do not easily extend globally. Because of the long residence time of Re in the oceans, the Re isotope proxy can likely track changes in the extent of suboxic conditions globally in the ocean. Previous publications provided methods for digesting and purifying Re for δ187Re analysis from different materials (e.g., seawater, basalt, sedimentary rocks, chondrites; Miller et al., 2015, Liu et al., 2017, Dellinger et al., 2019, Dickson et al., 2020). These publications set the foundation for creating a δ187Re ocean mass balance. However, there is as yet no method that specifically targets the authigenic Re in shales, which has the potential to directly capture δ187Re of contemporaneous seawater. Here, we report a novel method for digesting samples that is done in a single step that excludes the use of HF, utilizing the well-established Carius tube (CT) digestion technique. By not using HF, this method does not dissolve the silicate portion of samples, allowing the targeted removal of authigenic Re. We also introduce a two-step column chemistry approach that can be utilized to purify Re from large samples with very low Re concentrations. We are applying this new method to characterize δ187Re in modern euxinic and suboxic settings including the Black Sea and the Benguela margin. 

Abstract The driving forces, kill and recovery mechanisms for the end-Permian mass extinction (EPME), the largest Phanerozoic biological crisis, are under debate. Sedimentary records of mercury enrichment and mercury isotopes have suggested the impact of volcanism on the EPME, yet the causes of mercury enrichment and isotope variations remain controversial. Here, we model mercury isotope variations across the EPME to quantitatively assess the effects of volcanism, terrestrial erosion and photic zone euxinia (PZE, toxic, sulfide-rich conditions). Our numerical model shows that while large-scale volcanism remains the main driver of widespread mercury enrichment, the negative shifts of Δ¹⁹⁹Hg isotope signature across the EPME cannot be fully explained by volcanism or terrestrial erosion as proposed before, but require additional fractionation by marine mercury photoreduction under enhanced PZE conditions. Thus our model provides further evidence for widespread and prolonged PZE as a key kill mechanism for both the EPME and the impeded recovery afterward.