21 research outputs found
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Delivering authentic online practical science teaching – geoscience perspectives from the OpenScience Laboratory
Teaching practical science at a distance is challenging – how do you give students studying online a meaningful practical experience? In July 2013, the Open University (OU) launched the Wolfson OpenScience Laboratory (OSL) to deliver a wide a range of authentic practical science activities for their distance learning undergraduates. Prompted by the recognition that modern science is increasingly conducted via a computer screen (e.g. remote sensing, Martian fieldwork), the OSL presents a variety of opportunities for students to observe, investigate, gather and analyse data. The rationale is to foster problem-based, active learning, which has been proven effective by numerous studies. Simulation is kept to a minimum; most activities either generate or use real data, with authentic anomalies and ‘noise’ included – an aspect valued by the students. Geoscience is rooted in raw data collected during practical investigations, notably fieldwork. A key skill is observation, so the OSL includes digital collections of minerals, rocks and fossils, as zoomable, high resolution images and 360° videos for the 3D perspective. The Virtual Microscope enables petrographic examination of thin sections using high-quality zoomable images, in both plane- and cross polarised light, with rotation of the sample for certain points of interest. There is a virtual field trip based in a multi-user virtual environment (MUVE), as well as an exercise on maps and landforms. Developed primarily for OU undergraduates, many of the assets in the OSL are being made more openly accessible, with free registration. We are developing partnerships with other universities and schools, both as users and contributors to further assets (e.g. thin section collections). We have also gathered feedback from several surveys of OU undergraduates, as well as external users. Feedback on the pedagogical aspects of the OSL is broadly positive, with some assets (e.g. the virtual microscope) garnering particular praise; respondents value the potential for interaction with experts but also desire an explicit connection to the materials’ original field context. However, technological issues at times present a barrier to learning – perhaps reflecting the high diversity of OU cohorts, especially in terms of their individual hardware, software and IT skills. Some students resent the time investment required to master specialised scientific software, though it could be argued that acquiring such IT skills is an essential part of practising modern science
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FieldscapesVR: Virtual world field trips to extend and enrich field teaching
Field teaching is an indispensable feature of geoscience education, at all levels. However, delivering effective field experiences is challenging under many circumstances – not least for distance students such as Open University (OU) undergraduates. Hence, OU geoscience modules over the last 25 years have featured virtual field trips (VFTs), exploiting a range of formats, typically delivered via CD-ROM, DVD or web browser. 2013 saw a dramatic reboot with the launch of Virtual Skiddaw, a field exercise framed in a multi-user virtual environment that was created using 3D gaming software (Unity 3D). Virtual world field trips (VWFTs) offer a wealth of new opportunities for online field learning. Advances in scanning and photogrammetry make detailed observation possible, while the digital landscape and ambient audio foster immersion. Rather than merely trying to replicate an outdoor field trip, the VWFT can also go ‘beyond fieldwork’: users can access aerial perspectives; drape the digital landscape with different imagery (e.g. maps); teleport and fly to save time; call up subsurface cross-sections; even fade other avatars out if they are obscuring the view! The multi-user capability enables collaborative work, even among groups that are widely dispersed, as OU students are. There are times when a VFT can replace physical fieldwork, for example for those who cannot access the outdoor locations. However, we regard their primary role as support for physical field teaching, so that students can make the most of their, often limited, time in the field: pre-trip familiarisation and orientation, followed by post-trip revision, reflection or extension – for both educators and students; introducing basic fieldwork concepts and logistics, risk assessment, and even some fieldwork skills – for instance to students with no prior field experience – to alleviate anxiety and build confidence. For example, in Virtual Skiddaw both mapwork and compass skills can be practised in the context of a 3D landscape. VWFTs also facilitate development of spatial literacy skills by bridging the 2D/3D conceptual gap, promote active learning, foster collaborative skills and reinvigorate problem-solving exercises
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Boosting the petrochronology arsenal: REE partitioning between garnet and monazite in Bhutanese pelitic metasediments
Metamorphic studies are increasingly striving to integrate timing information with petrographic analysis and thermobarometry – the developing field of petrochronology. Recent advances in analytical techniques, in particular a variety of in situ methods that can potentially extract the information preserved in disequilibrium features, have reinvigorated metamorphic studies. The strength of petrochronology lies in linking the isotopic age directly to the metamorphic stage, in contrast to earlier studies where accessory phase ages existed in isolation from the thermobaromatric data with which they were tentatively linked. Garnet has proved itself an invaluable tool in metamorphic studies, yielding microstructural, thermobarometric, geochemical and even geochronological information. Although common in amphibolite-facies pelitic metasediments, garnet does not easily yield its chronological data, so the common accessory phase monazite has been used more routinely. Typically, monazite isotopic ages cannot be linked to the development of different metamorphic assemblages because their textural relationships, especially with fabric-forming phases, are commonly obscure. However, their distribution as matrix grains versus inclusions in porphyroblast minerals such as garnet, or in retrograde textures, can yield useful information. In situ investigations of chemical zoning in both monazite and garnet offer the potential to link crystallisation of the two minerals more closely. Since both monazite and garnet incorporate rare earth elements (REE), their equilibrium partitioning behaviour provides not only a useful test of equilibration, but also a way of linking time to temperature. Previously reported garnetmonazite partitioning data record the behaviour expected under granulite-facies (>750°C) conditions. We document REE concentration data from sub-solidus amphibolite-facies (~650-700°C) rocks from the eastern Himalaya (Bhutan), where age and inclusion relationships suggest that garnet and monazite grew simultaneously. The garnet/monazite ratios show steeper heavy REE patterns than those reported from the higher-temperature experimental data. These data suggest either that the partitioning relationships vary with temperature, or that different relationships hold in sub-solidus vs. supra-solidus rocks. Bhutan is an excellent location to test these relationships; abundant pelitic metasediments within a single tectonic unit span metamorphic grades ranging from sub-solidus to supra-solidus. Moreover, these metamorphic rocks (and their counterparts along the strike of the orogen) have been extensively studied in recent years both in terms of their metamorphism and their monazite geochronology, providing an ideal framework for petrochronological research with applications to all major orogens
Tectonic interleaving along the Main Central Thrust, Sikkim Himalaya
Geochemical and geochronological analyses provide quantitative evidence about the origin, development and motion along ductile faults, where kinematic structures have been overprinted. The Main Central Thrust is a key structure in the Himalaya that accommodated substantial amounts of the India–Asia convergence. This structure juxtaposes two isotopically distinct rock packages across a zone of ductile deformation. Structural analysis, whole-rock Nd isotopes, and U–Pb zircon geochronology reveal that the hanging wall is characterized by detrital zircon peaks at c. 800–1000 Ma, 1500–1700 Ma and 2300–2500 Ma and an εNd(0) signature of –18.3 to –12.1, and is intruded by c. 800 Ma and c. 500–600 Ma granites. In contrast, the footwall has a prominent detrital zircon peak at c. 1800–1900 Ma, with older populations spanning 1900–3600 Ma, and an εNd(0) signature of –27.7 to –23.4, intruded by c. 1830 Ma granites. The data reveal a c. 5 km thick zone of tectonic imbrication, where isotopically out-of-sequence packages are interleaved. The rocks became imbricated as the once proximal and distal rocks of the Indian margin were juxtaposed by Cenozoic movement along the Main Central Thrust. Geochronological and isotopic characterization allows for correlation along the Himalayan orogen and could be applied to other cryptic ductile shear zones
The impact of the Great Exhibition of 1851 on the development of technical education during the second half of the nineteenth century
This paper examines the contribution made by the mechanics’ institute movement in Britain just prior to, and following, the opening of the Great Exhibition of 1851 in London. It argues that far from making little contribution to education, as often portrayed by historians, the movement was ideally positioned to respond to the findings of the Exhibition, which were that foreign goods on display were often more advanced than those produced in Britain. The paper highlights, through a regional study, how well suited mechanics’ institutes were in organising their own exhibitions, providing the idea of this first international exhibition. Subsequently, many offered nationally recognised technical subject examinations through relevant education as well as informing government commissions, prior to the passing of the Technical Instruction Acts in 1889 and the Local Taxation Act of 1890. These acts effectively put mechanics’ institutes into state ownership as the first step in developing further education for all in Britai
The origins and histories of metasedimentary units in the core of the Himalaya
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Developing an inverted Barrovian sequence; insights from monazite petrochronology
In the Himalayan region of Sikkim, the well-developed inverted metamorphic sequence of the Main Central Thrust (MCT) zone is folded, thus exposing several transects through the structure that reached similar metamorphic grades at different times. In-situ LA-ICP-MS U–Th–Pb monazite ages, linked to pressure–temperature conditions via trace-element reaction fingerprints, allow key aspects of the evolution of the thrust zone to be understood for the first time. The ages show that peak metamorphic conditions were reached earliest in the structurally highest part of the inverted metamorphic sequence, in the Greater Himalayan Sequence (GHS) in the hanging wall of the MCT. Monazite in this unit grew over a prolonged period between ∼37 and 16 Ma in the southerly leading-edge of the thrust zone and between ∼37 and 14.5 Ma in the northern rear-edge of the thrust zone, at peak metamorphic conditions of ∼790 °C and 10 kbar. Monazite ages in Lesser Himalayan Sequence (LHS) footwall rocks show that identical metamorphic conditions were reached ∼4–6 Ma apart along the ∼60 km separating samples along the MCT transport direction. Upper LHS footwall rocks reached peak metamorphic conditions of ∼655 °C and 9 kbar between ∼21 and 16 Ma in the more southerly-exposed transect and ∼14.5–12 Ma in the northern transect. Similarly, lower LHS footwall rocks reached peak metamorphic conditions of ∼580 °C and 8.5 kbar at ∼16 Ma in the south, and 9–10 Ma in the north. In the southern transect, the timing of partial melting in the GHS hanging wall (∼23–19.5 Ma) overlaps with the timing of prograde metamorphism (∼21 Ma) in the LHS footwall, confirming that the hanging wall may have provided the heat necessary for the metamorphism of the footwall.
Overall, the data provide robust evidence for progressively downwards-penetrating deformation and accretion of original LHS footwall material to the GHS hanging wall over a period of ∼5 Ma. These processes appear to have occurred several times during the prolonged ductile evolution of the thrust. The preserved inverted metamorphic sequence therefore documents the formation of sequential ‘paleo-thrusts’ through time, cutting down from the original locus of MCT movement at the LHS–GHS protolith boundary and forming at successively lower pressure and temperature conditions. The petrochronologic methods applied here constrain a complex temporal and thermal deformation history, and demonstrate that inverted metamorphic sequences can preserve a rich record of the duration of progressive ductile thrusting