TS11.1 | Digital outcrops: applications and developments in research, education, and outreach
Digital outcrops: applications and developments in research, education, and outreach
Co-organized by EOS2/SSP1
Convener: Amerigo CorradettiECSECS | Co-conveners: Marco MercuriECSECS, Silvia Mittempergher, Adam CawoodECSECS, Simon Buckley
| Mon, 24 Apr, 08:30–10:15 (CEST)
Room D1
Posters on site
| Attendance Mon, 24 Apr, 16:15–18:00 (CEST)
Hall X2
Posters virtual
| Attendance Mon, 24 Apr, 16:15–18:00 (CEST)
Orals |
Mon, 08:30
Mon, 16:15
Mon, 16:15
The realization and use of digital outcrops has become a routine way to collect and share geological information, both quantitively and qualitatively. This session aims to promote optimal workflows and expertise sharing through contributions where the use of digital outcrop models and – more in general – virtualization has been essential for the fulfillment of application and project goals. This includes research, education, outreach, and dissemination. We welcome all contributions based on digital outcrops including (i) geological case studies, (ii) methodological studies related to 3D modelling and interpretation (e.g. photogrammetric survey design, model reconstruction, interpretation, data extraction and automation, statistical analysis), (iii) construction and delivery of virtual field trips, (iv) application in geoscience education, (v) public outreach involvement, and (vi) improving diversity, equity, and inclusion. Early-career scientists and students are particularly encouraged to submit a contribution.

Orals: Mon, 24 Apr | Room D1

Chairpersons: Amerigo Corradetti, Marco Mercuri
On-site presentation
Mariia Oliinyk, Ihor Bubniak, Andrij Bubniak, Yevhenii Shylo, Mykola Bihun, and Yuriy Vikhot

Structural studies foresee a detailed three-dimensional model. In this work we present the results of constructing a virtual outcrop at the quarry base in the city of Turka. Such objects are especially valuable for structural geology, sedimentology, mining, etc.

From a geological point of view, it is located in the Outer Ukrainian Carpathians, tectonically it belongs to the Krosno nappe. Here, the rocks are mainly represented with sandstones, siltstones and argillites.

Workflow. The study predicted: 

- Reconnaissance of the object (detailed overview of the object of research, determination of future positions of control and reference points, and standing stations);

- Establishing and determining the coordinates of reference points (placement of six black and white marks);

- Determining the coordinates of control points (fixation on the outcrop body using the electronic total station Leica TCR 405);

- A terrestrial laser scanning process (3/4 scanning points are located approximately on the same line with a step of 25 and 15 meters, the fourth station is located at the top of the right slope of the quarry, the elevation is 29 m; scanning was performed with a Leica ScanStation C10 scanner);

- Photographing the object (in order to improve the quality of the future mesh model, some details and textures. 344 pictures were taken with a Canon Mark 3 5D digital camera);

- Creating a point cloud based on laser scanning data (Processing was performed in the Leica Cyclone Register 360 program. Five reference points were used to orient the cloud of points in the coordinate system);

- Creating a mash model based on point clouds and digital images (This step was done in the Reality Capture program. The accuracy of the mash model was assessed by comparing the coordinates of control points obtained from the mash model and surveying with TPS; the absolute spatial difference does not exceed five centimeters).

The geological field camp was financed by American Association of Petroleum Geologists (AAPG) for the first author.

How to cite: Oliinyk, M., Bubniak, I., Bubniak, A., Shylo, Y., Bihun, M., and Vikhot, Y.: Creation of 3D model of the Turkа quarry using terrestrial laser scanning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-364, https://doi.org/10.5194/egusphere-egu23-364, 2023.

On-site presentation
Hanting Zhong, Jianhua Chen, Zongqi Lin, Shuaiqi Wang, Mingcai Hou, Yalin Li, and Chengshan Wang

Outcrops are the focus of geological research. Oblique photogrammetric technology with the aid of unmanned aerial vehicles can build 3D digital outcrop models and further help to achieve visualization research of outcrops, which provides new ideas to solve the problems of low efficiency, high risk, and poor data reusability that exist in traditional geological research methods. This paper investigates the key technologies of 3D modeling of oblique images, 3D visualization of digital outcrops, and visualization of panoramic models, and design and implement a Web platform named DDE-Outcrop3D for real-scene 3D digital outcrops based on the Cesium open-source 3D earth engine. The platform achieves the visualization of high-precision 3D models of geological outcrops and combines the outcrop-related information such as text, pictures, videos, panoramas, documents, observation stops, and geological plotting with 3D outcrop models, realizing upload and panoramic roaming of 3D models of outcrops and self-supply, sharing, and visualization of outcrop-related information. As the first choice for the virtual field trips of the 21st International Sedimentological Congress, the platform has been successfully applied to 12 of the 15 field routes. Compared with traditional geological research methods, the visualization of 3D outcrops can help geologists understand the spatial and temporal distribution of geological phenomena and features of outcrops more comprehensively and intuitively. This platform also achieves the co-construction and sharing of resources of outcrops under digital environment, saving the time and economic costs of geological expeditions.

Keywords: Oblique photogrammetry, Real-scene 3D outcrops, Cesium, Visualization platform

How to cite: Zhong, H., Chen, J., Lin, Z., Wang, S., Hou, M., Li, Y., and Wang, C.: Fieldwork anytime!——The functions and applications of DDE-Outcrop3D, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2729, https://doi.org/10.5194/egusphere-egu23-2729, 2023.

Virtual presentation
Gautier Laurent, Celine Mallet, Thomas Dewez, Louis Lefrançois, Bouamama Abbar, Mohamad Abbas, and Mohamed Azaroual

The Observatory of the Vadose Zone (OZNS) is addressing the role of the unsaturated zone in the transfers of water, heat, and pollutant, between the soil and the aquifer. This project implements a unique observatory within the Beauce Limestone Formation at Villamblain (France). This observatory consists of a large central well (20 m deep and with a diameter of 6.1 m) surrounded by satellite drill holes and surface installations within an area with a radius of a few tens of meters. The overall observatory spans from the surface down to 25 m depth, reaching the aquifer and the barrier layer of the Molasses du Gâtinais. The instrumented surface, central well, and satellite drill holes will produce decade-long records of the vadose zone to evaluate its impact on water and pollutant transfers, while monitoring its long-term evolution in a context of climate change.


The large central well is primarily designed for easily installing, maintaining, and testing geophysical and hydrological sensors over the lifetime of the observatory, but it also provides a unique chance to observe the complex structuration of the vadose zone and its host. In particular, the scale and configurations of the site provide a unique view of these rocks. They are made accessible at a micro-to-decametric scale, which extends drill core observations, and provide a nearly 3D view. This is interesting by comparison with typical outcrops at that scale (e.g., quarries), which are mostly 2D. Preliminary observations, from surrounding drill cores, revealed a particularly complex limestone formation, which consists of a series of terrestrial limestones, with palustrine and lacustrine facies and breccias, affected by a long history of fractures and alterations, silicification, and karstification. A very detailed characterisation of these facies thus requires to provide a high-resolution context for the various measurements and simulations of the transfers in the vadose zone.

This contribution presents the construction of the numerical architecture and the acquisition process implemented for accommodating the very restricted access to direct observations during the construction of the well, which encompasses laser scanning (lidar) and high-resolution photogrammetry. The implications of the different acquisition protocols implemented during the process are discussed in terms of impacts on resolution, coverage, and spatial accuracy. The scanning was performed through 14 distinct stages, where only around 1.5 m height was accessible each time. One of the challenges was thus to stitch the different model rings into a common model. In the end, a complete model of the well surface was recorded with an average resolution of 3 pixels per millimetre.

How to cite: Laurent, G., Mallet, C., Dewez, T., Lefrançois, L., Abbar, B., Abbas, M., and Azaroual, M.: Digital Outcrop Acquisition for the Observatory of the Vadose Zone (OZNS), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15336, https://doi.org/10.5194/egusphere-egu23-15336, 2023.

On-site presentation
Perrine Mas, Raphaël Bourillot, Benjamin Brigaud, Rémy Deschamps, and Bertrand Saint-Bezar

The construction and interpretation of digital outcrop models (DOM) from outcropping reservoir analogues enable to capture and characterize reservoir heterogeneities (in terms of facies, diagenesis, and petrophysical properties) from centimeter to kilometer scales, thus allowing to improve upscaling approaches in 3D reservoir modeling. Digital outcrop models offer a reliable tridimensional representation of sedimentary heterogeneities, which can strongly impact fluid flow and therefore geothermal reservoir exploitation.


The Roda Sandstones (Lower Eocene) are considered as a world-class outcropping example for deltaic sedimentary systems outcropping in the Graus-Tremp Basin (South Pyrenean Basin). Thanks to the quality of its outcrops and to the drilling of 50 to 80-meter-long cores in their vicinity, the Roda Sandstones are commonly used for educational and research purposes (Crumeyrolle et al., 1992; Martinius, 2012).


Over the past 15 years, a few digital outcrop models have been published from the Roda Sandstones (Enge et al., 2007; Leren et al., 2010). These models were only constructed at a small scale (decimeter to hectometer) and did not allow to capture the large-scale architecture of the Roda fluvio-deltaic system. In this study, we built a complete photogrammetric model of one of the prograding sand wedges of the Roda Sandstones (also called Y body) from more than 11000 photos acquired by drone. The model is accurately georeferenced thanks to a dGPS campaign carried out simultaneously with the drone acquisitions. This outcrop model covers a total area of about 4km², and the pixel resolution ranges between 3 mm and 3 cm.


A significant amount of quantitative and qualitative information could be extracted from this digital outcrop model, that helps at constraining the reservoir model. Its interpretation in a software dedicated to the geological interpretation of DOMs enabled to take measurements (e.g., dips, distances, etc.), to identify and to trace the main stratigraphic surfaces, locate the field observations and samples, allowing to precisely assess the architecture and the facies distribution of the Y sandbody.


The results show a multiphase sandbody, made up of different prograding lobes, with variable progradation directions and a diversity of sedimentary structures formed by the competition between fluvial and tidal currents, contributing to the complexity of the sedimentary system. Paleocurrent directions, sediment thicknesses, numerical outcrops painted in facies, digitized sedimentological sections, and boreholes interpreted in facies were used as input data to build a static facies model. The geological static model was then filled with porosity and permeability properties and used as a base for fluid flow simulations in order to assess the impact of sedimentary heterogeneities in deltaic reservoirs for geothermal exploitation purposes.

How to cite: Mas, P., Bourillot, R., Brigaud, B., Deschamps, R., and Saint-Bezar, B.: From 3D digital outcrops to fluid flow reservoir simulations in a deltaic system: An integrated approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-565, https://doi.org/10.5194/egusphere-egu23-565, 2023.

Virtual presentation
Simon Hutchinson and Amy Evans

Although the use of digital outcrops may have become a routine way to collect and share geological information, this approach is less well used as a communication tool in geomorphology, whether to support students’ understanding of landform processes or to engage the public in a scientific understanding of landscape features. This study sets out the use of 3D landform and outcrop models in virtual field trips (VFTs); initially developed as a COVID response when fieldwork was curtailed, but subsequently refined to support the Learning Outcomes of in-person fieldwork, as well as to promote Equity, Inclusion, Diversity (EDI) and Access in Environmental Education. On the basis of techniques developed for geoscience in Higher Education, digital visualisation tools (DVTs) have also been applied to reach out and facilitate the (virtual) accessibility of less accessible terrain.

Accessing the efficacy of the use of VFTs to augment the real-world experience of fieldwork in our Geography and Environmental Management degrees indicates that students are positive in engaging with these DVTs to support their learning. Moreover, VFTs can facilitate the inclusion of those unable to participate directly. 3D landform models are particularly useful in providing context and scale for VFTs but can be limited by surface distortion effects when some secondary sources are employed. Bespoke models, made through drone-based photogrammetry in particular, can significantly enhance the fieldwork experience. The additional perspectives they can provide, made available either alongside or directly in the field (i.e., on a mobile device) via interactive features, act effectively as an accessible ‘remote’ guide. Nevertheless, digital tools are seen as augmenting in-person field trips rather than as a replacement.

Given the recent enhanced interest in outdoor activities and the greater familiarity of much of society with digital devices, DVTs also offer a significant opportunity for public outreach with an Environment focus. Tegg’s Nose Country Park (NW England) includes a RIGG (Regionally Important Geological and Geomorphological Site). Working collaboratively with the Park Ranger, the existing geological trail has been enhanced using DVTs to provide a VFT along the route and 3D models of the key outcrop and landform features. We aim to highlight the educational dimension of the Park’s provision and better link the hub of the Park, where there are facilities, with the wider site which is less well used due to its layout and terrain. Engaging virtually provides potential visitors with a greater level of confidence and an enhanced awareness of the site’s features, promoting positive engagement and behaviours.

Challenges in widening the use of DVTs lie in the provision of non-specialist interfaces and access to resources to facilitate their use by the widest range of Educators to promote inclusion and support outreach. Applications also need to remain mindful of the format that viewers will probably employ i.e., hand-held devices which may not have Internet access when really needed e.g., in the ‘real’ field.

How to cite: Hutchinson, S. and Evans, A.: Going digital in landform fieldwork: fad or opportunity and challenge?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5122, https://doi.org/10.5194/egusphere-egu23-5122, 2023.

On-site presentation
Juergen Lang and Daniel Koehn

A major part of Northern Bavaria in Southeast Germany is covered by sedimentary rocks of the Franconian Platform (mainly sandstones, mudstones and limestones). These Permo-Mesozoic continental to shallow marine sediments overlay the Variscan basement and are partially affected by Syn-Variscan structures (Freudenberger and Schwerd, 1996). Further tectonic overprint including Permo-Mesozoic basin extension, Cretaceous inversion and Cenozoic intraplate deformation (e.g., Wiest et al. unpublished) developed a complex fault system. Regionally sparse drill core data as well as large forestry and agricultural cultivation complicate the structural interpretation of the entire area. Drone photogrammetry 3D models from locally selected limestone quarries provide a perfect insight into the structural evolution of Northern Bavaria. Centimetre to several hundreds of metres scale faults, joints and folds are clearly visible and measurable within the models. These local photogrammetry models are implemented into a large scale (Franconian Platform) interpreted 3D model which helps to understand and visualize the major structural features. The photogrammetry models can be used for regional and structural geology teaching purposes. A finished large scale 3D model will be made publicly available through the Bavarian State Office for the Environment LfU (www.lfu.bayern.de).



Freudenberger, W., and Schwerd, K., 1996, Erläuterungen zur Geologischen Karte von Bayern 1:500 000, München, Bayerisches Geologisches Landesamt, 329 p.

Wiest, J.D., Köhn, D., Stollhofen, H., and Dengler, K., The fault network of the Franconian Platform (SE Germany) – workflow, uncertainty, scaling, implications, unpublished.

How to cite: Lang, J. and Koehn, D.: Structural Visualization of Permo-Mesozoic Sediments in Northern Bavaria, Germany – Drone Photogrammetry as a practical Tool for large Areas, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7755, https://doi.org/10.5194/egusphere-egu23-7755, 2023.

On-site presentation
Stefano Casiraghi, Andrea Bistacchi, Federico Agliardi, Gloria Arienti, Bruno Monopoli, Giovanni Dal Piaz, and Davide Bertolo

The study and characterization of fracture network find applications in a wide range of fields, from the analysis and modelling of mechanical and hydraulic properties of rock masses, to petroleum reservoirs, waste repositories, aquifers and Carbon Capture and Sequestration (CCS). In this context, the use of Digital Outcrop Models (DOMs), overcame the limitations of the classic field survey, such as limited access and logistics, providing a solid framework for the collection of large and quantitative datasets. Here we present a semi-automatic workflow for DOMs structural interpretation, carried out on outcrops of fractured gneiss, prasinites and calcschist of the Dent-Blanche Nappe and Combin Zone, exposed on the Italian side of the Cervino/Matterhorn in Valtournenche. Our methodology is based on a combination of traditional field survey and remote sensing techniques (photogrammetry or laser scanning). The preliminary step is the selection of representative outcrops in terms of structural and lithological properties of a larger rock volume, based on a thorough knowledge of regional structural geology and tectonics; moreover, the outcrop must be representative in terms of morphology and orientation. At this stage it is important to select outcrops that have several faces (e.g. vertical face and a horizontal pavement), so it will be possible to evaluate both the orientation and height distribution on the vertical face and the length distribution on the horizontal “pavement”. The main purpose of the traditional field survey is the analysis of kinematics, relative chronology and mineralization - all parameters needed to characterize fracture sets in terms of their genesis and deformative evolution. At the same time, remote sensing dataset are collected and the output is a point cloud DOM (PC-DOM) colorized with RGB values. After a pre-processing phase where the PC-DOM is cleaned from edge noise (resulting from the photogrammetric processing), vegetation and debris (naturally present in most outcrops), orientation data are collected manually, using suitable software tools (e.g. Compass plugin in CloudCompare or PZero). This step allows, together with the results of the field survey, selecting different fracture sets and characterizing their orientation statistics. The second step consist in a manual segmentation of the PC-DOM based on the previous characterization of fracture sets. In the final step, data are automatically extracted using specific algorithm calibrated based on previous steps (e.g. FACETS plugin in CloudCompare). In the end, this workflow aims at maximizing data collection from DOMs to be used as a basis for the subsequent extraction of statistical parameters such as length and height distribution, orientation statistics, abutting and crosscutting relationship between different sets, connectivity, etc.

How to cite: Casiraghi, S., Bistacchi, A., Agliardi, F., Arienti, G., Monopoli, B., Dal Piaz, G., and Bertolo, D.: Structural interpretation of Digital Outcrop Models on point clouds using a semi-automatic workflow: case studies on fractured metamorphic rocks (Aosta Valley, Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9632, https://doi.org/10.5194/egusphere-egu23-9632, 2023.

On-site presentation
Valentin Laurent, Louise Guillaume, and Matthew Genge

Fieldwork is a pedagogical cornerstone of many geoscience degrees. During the academic year 2020-21, the worldwide COVID-19 pandemic made outdoors fieldwork difficult, resulting in an urgent need to develop virtual alternatives. However, there is still more to learn about the impact of teaching fieldwork virtually on the student learning experience. This study aims to compare the student learning experience during virtual and outdoor fieldwork and establish the value of digital techniques to improve the inclusivity of geosciences degrees. Quantitative and qualitative data were collected to assess students’ attitudes to both outdoor and virtual fieldwork in terms of accessibility, inclusivity and their learning experience. Our results show overall positive student responses to virtual fieldwork, with over half stating it adequately replicated the learning experience of outdoor fieldwork. Students also value outdoor fieldwork for the degree of autonomy it provides, and idea-sharing with peers; yet simultaneously the majority believed outdoor fieldwork is inherently exclusionary. This study concludes that virtual fieldwork, taught using interactive three-dimensional virtual outcrops set within virtual worlds, replicates the outdoor fieldwork learning experience as closely as possible. However, students missed some fundamental and important aspects of outdoor fieldwork, such as being outside in an immersive environment, or the social interactions with peers and staff that are specific to on-location fieldwork. This study recommends the use of virtual fieldtrips in addition to residential on-location fieldwork, as for a significant number of students virtual fieldwork may be a better way of accessing this valued pedagogy of the geosciences. Furthermore, virtual fieldwork has the potential to make geosciences more inclusive and attractive to a wider range of students.

How to cite: Laurent, V., Guillaume, L., and Genge, M.: Geological fieldwork in the time of COVID-19: Comparing the student learning experience during virtual and outdoor fieldwork, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5926, https://doi.org/10.5194/egusphere-egu23-5926, 2023.

On-site presentation
Marco De Matteis, Oscar Gratacós, Oriol Ferrer, Eduard Roca, David Garcia-Sellés, Miguel López-Blanco, Patricia Cabello, and Fernando Borràs

One of the elements that have traditionally been used in Earth Sciences and in the social dissemination of geological knowledge is the visit to outcrops. During COVID pandemic, however, the educational community was forced to consider alternatives to field-based learning through the application of outcrop digitization technology and the development of virtual field trips to make them accessible from home. These digital teaching and learning methodologies, instead of disappearing after the removal of mobility restrictions by COVID, have spread and are already considered a complement to field-based learning in Earth Sciences and in other disciplines. In this sense, digital content specifically adapted to educational curricula through information and communication technologies (ICT) has proliferated.


Virtual outcrops, created using drone-based photogrammetry or LiDAR, optimize fieldwork with an educational or informative nature by complementing the “in situ” visits. Also, they allow blended learning of areas that cannot be visited due to lack of time, distance, or accessibility. In any case, the virtual outcrops are a powerful teaching tool since: a) provide points of view that cannot be observed in the field; and b) allow a quick extraction and analysis of geological information (i.e. attitude of bedding, joints and fault planes, geometry of rock bodies, distribution of facies or lithologies, etc.) in the 3D space that can be used to complement or, in some cases, to substitute the collected ones in the field. For these reasons, we consider indispensable to expand and improve the creation of this type of digital content, not only to be able to complement (not replace) fieldwork and increase the training capacity of the students, but also to increase the digital database and cope with possible future situations with mobility restrictions. In this scenario, the number of virtual outcroppings available or ready for teaching are still small and most of them do not include teaching tools.


The objective of this work is to generate educational content by means of disruptive digital technologies applied to geological outcrops in the Sallent area to expand and facilitate the dissemination capabilities, use, and teaching possibilities of these digital contents at BSc. and MSc. studies of Earth Sciences. The target area corresponds to the Southern deformation Front of the Pyrenees within the Ebro foreland basin. At surface, outcrops are made of upper Eocene fluvial-lacustrine fine-grained terrigenous, limestone, and gypsum strata. Deformation is characterized by decametric to hectometric scale thrusts, backthrusts, and folds detached on the Cardona Salt Fm. These structures are clearly visible on the field due to the frequent colour changes in the sedimentary succession. The developed digital teaching tool includes several natural isolated outcrops and a continuous well-exposed railway trench section of hundreds of meters digitized combining drone-based photogrammetry and LiDAR.

How to cite: De Matteis, M., Gratacós, O., Ferrer, O., Roca, E., Garcia-Sellés, D., López-Blanco, M., Cabello, P., and Borràs, F.: Introduction of 3D digital outcrops in the teaching of Earth Science studies at the University of Barcelona: The Sallent case study (Ebro Basin), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12159, https://doi.org/10.5194/egusphere-egu23-12159, 2023.

Virtual presentation
Jan van Bever Donker, Delia Marshal, Matthew Huber, Rudy Maart, Luyanda Mayekiso, Henok Solomon, and Nompumelelo Mgabisa


During the recent worldwide lockdowns due to the COVID-19 pandemic, several institutions around the world, out of necessity replaced their customary field work with virtual field trips, using existing photographic materials gathered over many years conducting the same fieldtrip, causing the lecturers to conclude that this was a reasonable alternative as the marks scored were similar. 

Several years before the pandemic hit, UWC’s Applied Geology section had already embarked on the development of high-resolution virtual field tours (VFTs)to use as supplementary material in the provision of field education to our geology students, based on the geocognition concept.  This was done as rising costs and increasing health and safety rules effectively forced us to keep fieldwork for students to an absolute minimum, which is unacceptable in geology education. Additionally, in this manner, students could be exposed to classical geology sites from anywhere in the world without having to travel there, as an archive of prime teaching outcrops could be built like this.


We created the Virtual Field Tours using High Resolution Photography and constructed the tours using Pano2VR enhanced with videos and drone images. In three different projects we tested for learning gain after exposure to our VFTs by using identical pre and post VFT questionnaires. Pandemic restrictions forced us to replace our first-year introductory field trips by VFTs.

Key Results

In a final assessment testing for understanding of geological principles based on their usage of these VFTs, the assessment results for first year students showed encouraging signs of learning gains. In the second project we exposed second year students, third year students and Honours students as well as graduate geologists to the basic principles of slope stability in engineering geology. In this case we presented a lecture, followed by a questionnaire on the concepts mentioned, followed by the VFT and again the same questionnaire where we demonstrated a distinct learning gain. Finally, we used a lecture on basic characteristics of sedimentary features in turbidite deposits, enhanced by a comprehensive VFT to prepare Honours level students for a weeklong field trip. Comparing their final report with the final report of the previous year’s group of students also demonstrated learning gain.


While we acknowledge that real-life field work can never be replaced, we have demonstrated that properly designed VFTs can be successfully used to enhance learning at real-life field work.

How to cite: van Bever Donker, J., Marshal, D., Huber, M., Maart, R., Mayekiso, L., Solomon, H., and Mgabisa, N.: The effectiveness of using virtual reality materials in preparing students for geological fieldwork, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13788, https://doi.org/10.5194/egusphere-egu23-13788, 2023.

Posters on site: Mon, 24 Apr, 16:15–18:00 | Hall X2

Chairpersons: Marco Mercuri, Silvia Mittempergher, Simon Buckley
Stefano Tavani, Amerigo Corradetti, and Marco Mercuri

The rapid improvements of computer vision–based photogrammetric image processing pipelines (i.e., Structure from Motion–Multi View Stereophotogrammetry: SfM-MVS), coupled with the availability of various low-cost and portable acquisition tools, such as Digital Single-Lens Reflex (DSLR), mirrorless cameras, Unmanned Aerial Vehicle (UAV) and even smartphones, have revolutionized outcrop studies in structural geology and have brought traditional field geology into the digital age. This has had a transformative impact on Virtual Outcrop Models (VOMs), which have been promoted from mostly visualization media to fully interrogable quantitative objects. Among the several applications of VOMs in structural geology, extraction of near planar features (e.g., fracture and bedding surfaces) is one of the most important. Various procedures aimed at this purpose exist, spanning from fully automated segmentation and best fitting of point clouds to the manual picking of 3D polylines on both point clouds and textured meshes.

Here we illustrate the pros and cons, best practices, and drawbacks of the main procedures for near planar geological data extraction from VOMs. While automated or supervised recognition and subsequent best-fitting of coplanar patches in point clouds has received remarkable attention, its application generally limits to rare case studies. Indeed, most commonly, geological outcrops do not expose patches of near planar surfaces which are large enough to carry out a robust best fitting, and the structural interpretation of the outcrop only permits manual picking procedures. In the latter case, the use of textured meshes must be preferred to point clouds, and during digitization the accuracy of the textured mesh must be considered, as well as the intrinsic roughness of any geological surfaces. The analysis of coplanarity and collinearity of the picked pointsets may help in identifying traces that diverge from idealized (low) collinear and (high) coplanar configurations. However, typically suggested threshold values often produces small datasets. Nonetheless, the goodness of the extraction of data based merely on the visual inspection of the best-fit plane, handling coplanarity and collinearity in real-time through live computation of best-fit planes from picked pointsets, is often acceptable.

How to cite: Tavani, S., Corradetti, A., and Mercuri, M.: Extraction of 3D structural data from Virtual Outcrop Models: problems and best practices., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7446, https://doi.org/10.5194/egusphere-egu23-7446, 2023.

Ivan Kosović, Marco Pola, Bojan Matoš, Ivica Pavičić, Tihomir Frangen, Mirja Pavić, Morena Mileusnić, and Staša Borović

Carbonates extend on approximately 15% of the ice-free land surface, and approximately 16% of the global population lives in karst areas depending on its groundwater resources. The estimation of the permeability field in carbonate aquifers is crucial for their sustainable management. The presented research was conducted in the Daruvar hydrothermal system (DHS) in the north-eastern part of the Republic of Croatia. It is a typical hydrothermal system hosted in carbonate rocks with water temperatures up to 50 °C. DHS includes both the thermal spring area in the Daruvar area and the western slopes of Mt. Papuk, which are predominantly built of the Mesozoic carbonate rock complexes and represent the recharge area of the thermal system. The objectives of the research are: i) the geometric reconstruction of discontinuities that drive the fluid flow, and ii) the estimation of the hydrogeological parameters of the carbonate thermal aquifer using structural, photogrammetric, and hydrogeological approaches. The regional structural setting was analysed through field investigations evidencing the occurrence of a polyphase deformation. In particular, NNE-SSW compression and ESE-WNW extension were identified, which are consistent with the deformation phases of the Pannonian Basin. Outcrop analogues of the carbonates constituting the thermal aquifer and affected by comparable multi-phase deformation of the rock mass were selected to detail the role of fracture systems on the permeability field. At selected locations, detailed photogrammetric measurements will be carried out and the vectorization of the fractures will be performed for the construction of a virtual outcrop (2D display of fracture traces). The results will be used to evaluate the geometrical parameters of the fractures (e.g., orientation, mean trace length, density, intensity) being the input parameters for discrete fracture network (DFN) modelling. The reconstructed network of discontinuities will be tested through hydrogeological numerical modelling using the DFN approach, thereby enabling the estimation of the hydraulic parameters of the rock mass. The estimated hydraulic parameters will be correlated with the results of pumping tests conducted in the Daruvar area.

Acknowledgments: Presented research has been conducted in the scope of the project “Multidisciplinary approach to hydrothermal system modelling” (HyTheC) funded by the Croatian Science Foundation under grant number UIP-2019-04-1218.

How to cite: Kosović, I., Pola, M., Matoš, B., Pavičić, I., Frangen, T., Pavić, M., Mileusnić, M., and Borović, S.: Determination of geometrical parameters of fractures in Triassic dolomites: the case study of the Daruvar Hydrothermal System (Croatia), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8167, https://doi.org/10.5194/egusphere-egu23-8167, 2023.

Bernhard Grasemann, Michel Bestmann, and Michael Kettermann

Structure from Motion photogrammetry calculates 3D point clouds through identification of matching features in an overlapping series of pictures, from which textured 3D surfaces can be derived. This method has become increasingly popular in field geology because with the help of drone pictures, high-resolution digital outcrop models, digital elevation models or orthoimages can be produced at very high quality but low-costs.

Here, we use secondary electron images with micron-scale resolution to reconstruct the 3D geometry of a c. 400 μm quartz mineral fish using photogrammetry. The quartz fish from a marble ultramylonite from Thassos (Greece) has been extracted by an in situ etching technique (Bestmann et al., 2000, JSG, 22, 1789-1807). 57 secondary electron images captured at various stage rotations and stage tilts in a TESCAN Vega II scanning electron microscope were automatically aligned using the Structure from Motion software Agisoft Metashape (version 1.8.4). In order to increase the precision of the algorithm the background information of the images was removed using Adobe Photoshop and 15 marker points were identified in the images, which also helped to define a scaled coordinate system. We calculated a dense point cloud (c. 2.8 million points) from which a 3D model (c. 600000 faces) was derived on which the secondary electron image information was textured.

The tiled 3D model can be used to precisely measure parameters like volume, surface or shapes of the quartz fish either in Agisoft Metashape or from the exported 3D model using more specialized 3D analysis software (e.g. CloudCompare). Furthermore, features at the nanometer-scale like size and orientations of the grain boundaries or crystal faces of the dissolved calcite crystals, which surrounded the quartz fish, can be quantitatively investigated. After cleaning and down-sampling of the exported polygon mesh, the 3D surface can be transformed into a volume and eventually 3D printed. This method offers a great potential for quantitative investigations of the geometry and spatial relationship of microstructures and printed 3D models are a great haptic tool, which can be used in teaching and public outreach.

How to cite: Grasemann, B., Bestmann, M., and Kettermann, M.: High-resolution Structure from Motion modelling and 3D printing of Scanning Electron Microscopy data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8894, https://doi.org/10.5194/egusphere-egu23-8894, 2023.

Gabriele Benedetti, Stefano Casiraghi, Andrea Bistacchi, Gloria Arienti, and Davide Bertolo

With the rapid increase in computing power, 3D modelling and efficient visualization of complex geological features has become more common and accessible. We propose a new point cloud visualization and data analysis module for the open source 3D geomodelling software PZero (https://github.com/andrea-bistacchi/PZero) with the goal to carry out geological, and in particular structural, analysis on Digital Outcrop Models (DOMs). A solid codebase was implemented in PZero to import and analyse DOM data enabling the users to:

  • Import and visualize dense point cloud data sets

  • Calculate normals data if missing

  • Pick plane orientation

  • Segment the point cloud both manually and semi-automatically

The possibility to study and extrapolate properties from dense point clouds directly in a geomodelling software is a big advantage. Bistacchi et al. (2015) demonstrated that carrying out DOM analysis within a geomodelling package improves both the precision and the accuracy of the resulting 3D model, while Martinelli et al. (2020) demonstrated that reservoir-scale characterization could be carried out starting from the analysis of km-scale DOMs.

The open nature of PZero and the readability of its Python code, offers a clear advantage over other closed alternatives in terms of ease of editing and writing new functions. Moreover PZero is robust and efficient in visualizing dense datasets, allowing to easily render on a laptop point clouds reaching hundreds of millions of points. As a result large high-resolution DOMs can be exploited to map complex structures or to carry out dense statistical analysis at the reservoir scale. By including the DOM workflow in a geomodelling package, geologists can approach the modelling problem with new valid tools and techniques and seamlessly include in the final model quantitative and statistically robust properties.

How to cite: Benedetti, G., Casiraghi, S., Bistacchi, A., Arienti, G., and Bertolo, D.: Point cloud analysis and segmentation procedures in the PZero software, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9549, https://doi.org/10.5194/egusphere-egu23-9549, 2023.

Ian Abdallah, Canio Manniello, Fabrizio Agosta, and Giacomo Prosser

The use of field analogues in fractured reservoir studies is increasingly becoming popular because while large faults are mappable using geological and seismic data and small faults/fractures via well data, they are bound by certain limitations. For faults, it only provides limited information about dimensions, kinematics, and crosscutting relations with both primary and secondary heterogeneities visible at reservoir scales. More so, seismic scale data is unable to provide key information regarding fracture aperture, geometry, and overall degree of connectivity. This uncertainty hence deters working out realistic flow models, for this reason, the field analogues are used to generate digital outcrop models, bridging the gap between well log and core plug data and seismic data. The use of digital outcrop model approach to field analogues (outcrops) offers several advantages for the geoscientists. For instance, solving the inaccessibility challenges posed by some outcrops, allowing the geoscientists to better appreciate the structural architecture of diffuse and fault localised data at different scales of observation.

Our work involves the study of fractured and faulted Jurassic-Cretaceous platform carbonate rocks of the Viggiano Mt., southern Italy, which lie on the NE margin of the High Agri Valley, an intramontane Plio-Quaternary basin. We assess the geometry, distribution, kinematics of the high-angle faults, and the multiscale properties of both diffuse and fault-related fractures. The goal is to compute the transport and storage properties of the platform carbonates at outcrop-to-reservoir scale by building multiple DFN models. The outcrop scale models (50 m-side) are populated with field data and small fault data from structural interpretation of digital outcrop models. The porosity and equivalent permeability results from these models are used as matrix input for a medium size models (500 m-side) model populated with faults documented by digital outcrop analysis. The reservoir scale model (5 km-side) incorporates the latter petrophysical results as matrix input, whereas structural discontinuities are those reported in the 1:10,000 scale geological map of the study area.

Our methodology includes field data collection using linear scanline and circular scanline techniques. Data acquired digitally at late morning hours using a DJi Mavic II zoom drone with its generic camera model FC2204 (fixed focal length of 25mm, ISO -100, diaphragm opening of F/2.8, shutter speed of 1/200s), with a minimum of 280 digital images collected with >75% overlap for the 4 outcrops are processed using the Agisoft Metashape® software running on a computer with a Windows 10 OS equipped with a 64Gb Ram, an Intel core i9 (9th generation) processor and a NVIDIA GeForce RTX 2080 graphics card (32GB dedicated Ram). Structural data were extracted using the Open plot® and Cloud Compare®, are then processed using the FracpaQ®, and statistically computed using Microsoft Excel®. The data obtained on fracture attributes are inserted into Move® to build DFN models. As a result, the values of porosity and equivalent permeability are computed for the different structural configurations/scales. Preliminary results are consistent with small discrepancies existing between results obtained by field and digital structural analyses, and scale-dependant variations of the high-angle fault network.

How to cite: Abdallah, I., Manniello, C., Agosta, F., and Prosser, G.: From digital outcrops to DFN modeling of fractured platform carbonates, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9925, https://doi.org/10.5194/egusphere-egu23-9925, 2023.

Filippo Luca Schenker, Jodok Zwahlen, and Alessio Spataro

Remote sensing helps to evaluate quantitatively geological processes by increasing the precision of 3D geological maps, especially in areas that are poorly accessible. Here, we investigate the feasibility and the maximum obtainable resolution of digital geological maps of a heterogeneous High-Pressure ultramafic body (length of ca. 300 m) embedded within paragneisses of the Cima Lunga unit (Central Alps, Switzerland). The peridotite contains deformed mafic layers of amphibolite, eclogite, metarodingite or eclogitic metarodingite. Furthermore, calcsilicate layers locally cut the peridotite and are usually interpreted as ophicalcites that formed on the seafloor, prior to Alpine deformation and metamorphism.

Remote sensing data was acquired by an unmanned aircraft system (UAS) and elaborated with the software Aegisoft Photoscan for the image mosaic, Cloud compare for the Digital Elevation Model and QGIS for the visualizations. The model was georeferenced using ground control points, whose exact coordinates were obtained in the field using a GPS (with errors of ± 3 cm). In a first step, we mapped the ultramafic body using the 3D model, the orthoimages and the published geological data. In a second step, we mapped the ultramafic body in the field using our high-precision 3D topographic model (scale 1:1’000). In a last step, we fused the two maps and compared the different approaches in terms of precision of geological boundaries, lithological content and of work efficiency.

The results show that the map interpreted with the digital 3D model yields a high accuracy of the main ultramafic body (<1 m). However, internal small-scale geological features (e.g. mafic dikes <1.5 m) are very hard to distinguish, unless known from prior work. In addition, mapping with UAS images only is not reliable in suboptimal terrain such as loose rocks, grassy ledges, area with large light contrasts, etc.

In comparison, field mapping yielded a much more detailed map with lithological details up to 0.3 m, but the uncertainties of the lithological limits varied from 2.5 to 5 m associated with the precision of the localization in the field. In addition, the field observations helped with the geological interpretation across the partially covered outcrops. However, such an approach was time-consuming.

The fusion of both approaches combined the precision of the 3D model (<1 m) with the resolution of the fieldwork and allowed to resolve features as small as 0.3 m.

Finally, the final 3D map helped to clear up a geological feature: The calcsilicates cannot be considered metamorphosed ophicalcites that formed at the seafloor. Indeed, the map shows that calcsilica-breccias and migmatitic leucogneisses (presumably Alpine in age) together intruded the necking zones of the boudinaged ultramafic body, locally cutting the foliation of the peridotite.

How to cite: Schenker, F. L., Zwahlen, J., and Spataro, A.: Three-dimensional maps of a heterogeneous peridotite of the Cima Lunga unit: resolution of lithological limits and geological implication (Central Alps, Switzerland), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12094, https://doi.org/10.5194/egusphere-egu23-12094, 2023.

Sam Thiele, Ahmed J. Afifi, Sandra Lorenz, Raimon Tolosana-Delgado, Moritz Kirsch, Pedram Ghamisi, and Richard Gloaguen

Deep learning techniques are increasingly used to automatically derive geological maps from digital outcrop models, lessening interpretation time and (ideally) reducing bias. Such techniques are especially needed when hyperspectral images are back-projected to create data-rich ‘hypercloud’ type digital outcrop models. However, accurate validation of these automated mapping approaches is a significant challenge, due to the subjective nature of geological mapping and difficulty collecting quantitative validation data. This makes validation of different machine learning approaches for geological applications exceedingly difficult. Furthermore, many state-of-the-art deep learning methods are limited to 2-D image data, making application to 3-D digital outcrops (e.g., hyperclouds) an outstanding challenge.


In this contribution we present LithoNet, a benchmark digital outcrop dataset designed to (1) quantitatively compare learning approaches for geological mapping, and (2) facilitate the development of new approaches that are compatible with non-structured 3-D data (i.e., point clouds). LithoNet comprises two halves: a set of real digital outcrop models acquired at Corta Atalaya (Spain), attributed with different spectral and ground-truth data, and a synthetic twin that uses latent features in the original datasets to reconstruct realistic spectral data (including sensor noise and processing artifacts) from the ground-truth. We have used these datasets to explore the abilities of different machine learning approaches for automated geological mapping. By making it public we hope to foster the development and adaptation of new machine learning tools.

How to cite: Thiele, S., Afifi, A. J., Lorenz, S., Tolosana-Delgado, R., Kirsch, M., Ghamisi, P., and Gloaguen, R.: LithoNet: A benchmark dataset for machine learning with digital outcrops, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14007, https://doi.org/10.5194/egusphere-egu23-14007, 2023.

Deep crustal electrical structure imaging in the northern UAE using Magnetotellurics: Implications for Ophiolite emplacement and collisional tectonics
Biruk Cherkose and Hakim Saibi
Mutasim Osman

The King Fahd University of Petroleum & Minerals (KFUPM) campus features good exposure of the Eocene Rus Formation. This region, which is referred to as the Dammam Dome's apex, is what caused the Rus Formation's primary and secondary deformations. Despite the fact that these structures attracted numerous researchers and produced high-quality documentation and published work, a variety of data covering all the outcrops on the KFUPM campus is still lacking. In this study, 10 outcrops were used, and for each outcrop, high-resolution 3D photographs were captured together with sedimentological and structural data. The outcrops range in height from 5 to 7 meters, in width from 200 to 400 meters, and most of them include at least three distinct sets of fractures. The bed-by-bed sedimentological information includes lithology, grain size, texture, sedimentary structures, and fossils. The structural data also includes the thickness of the beds as well as the strike and dip of a representative number of fractures. To be used in the digital models, the images and all of the obtained data were geo-referenced. A new 3D outcrop model visualization and analysis tool has been created in-house, by the remote sensing team in KFUPM, with a focus on the ability to load and show massive outcrop model datasets in fully georeferenced coordinates (either in colored point cloud or textured TIN-mesh formats). Sedimentological and structural analysis tools have been created to do interactive study & annotation of the outcrop. All of the data from each outcrop were combined to form the results of this study, and the structural measurements were validated with an accuracy of +/- 5 degrees only for the measures of strike and dip. The Rus Formation digital models were also used to teach undergraduate students cutting-edge technologies and to bring the field into their desktops. Future plans and proposals call for integrating digital models with geophysical data such as seismic and GPR to increase value and benefits.

How to cite: Osman, M.: Digital Outcrop Modeling of The Eocene Rus Formation; Implications to Sedimentology and Structural Geology, Saudi Arabia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16415, https://doi.org/10.5194/egusphere-egu23-16415, 2023.

Posters virtual: Mon, 24 Apr, 16:15–18:00 | vHall TS/EMRP

Chairperson: Silvia Mittempergher
Giacomo Prosser, Fabio Olita, and David Healy

A study of the well-bedded carbonates of the Calcari con Selce formation (CCSf), exposed in the Agri valley (Basilicata, Italy), has been focussed on the control of large-scale folds and faults on the geometry of the fracture network. The CCSf is a 300-500 m thick late Triassic succession, consisting of pelagic carbonates, which were deposited within the Mesozoic Lagonegro basin. These carbonates represent excellent aquifers exploited for civil uses both in Basilicata and in the neighbouring regions of Southern Italy, therefore playing a very important role from a structural-geological and hydrogeological perspective. In particular, in the Agri valley a large number of springs are sourced from fractured carbonate rocks belonging to Apennine Platform and the Lagonegro Units. The High Agri Valley is a NW-SE oriented tectonic depression in the central sector of the Southern Apennines. The latter is a thrust and fold belt formed following the tectonic collision between the African and European plates during the since the early Miocene.

The CCSf is a multi-layered succession with carbonate layers containing chert levels and nodules, rare marly layers, and clayey intercalations. The selection of outcrop for the analyses has been performed taking into account distal and proximal basinal environment facies within the CCSf, and the presence of large-scale structures such as folds and faults. In each study area faults are characterized by different orientations and frequency, and folds display different geometry.

The goal was therefore to start from the study of orientation, density and intensity of fractures allowing to derive the specific porosity and permeability parameters. In each area the attributes of each set of faults, stratabound and non-stratabound fractures, veins and pressure solution cleavage were measured. The method used was to acquire data with linear scanline and circular windows using the classic field methods and integrating these measurements with drone-UAV acquisition of images to obtain digital outcrop models. The 3D model allowed the extraction of orthophotos which were digitized with a graphic software to identify the different structures that were processed in FracPaQ, to obtain qualitative and quantitative results for portions of the outcrop.

The geometry of the fracture network in each area has been compared with the geometry and kinematics large-scale structures, indicating a control of the major faults in the study area on the formation of the studied fracture networks. Moreover, we observed the strengths and weaknesses of the adopted measurement methods. The measurement of the data in the field allowed us to increase the accuracy in the measurement and to select the outcrops with the best exposure conditions. On the other hand, detailed fieldwork requires longer acquisition time and difficulty in reaching some outcrops can be encountered. The use of a UAV partly overcomes these problems, making it possible to study larger portions of outcrops in a shorter time. The integration of the different approaches and the advancement of digital techniques could be exploited or improved for future studies.

How to cite: Prosser, G., Olita, F., and Healy, D.: Study of the fractured carbonate aquifers of the Calcari con Selce formation in the Lagonegro Units integrating classical methods with modern digital techniques, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12738, https://doi.org/10.5194/egusphere-egu23-12738, 2023.