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COSC-2 operational report - Operational data sets

The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project focuses on mountain building processes in a major mid-Paleozoic orogen in western Scandinavia and its comparison with modern analogues. The transport and emplacement of subduction-related highgrade continent-ocean transition (COT) complexes onto the Baltoscandian platform and their influence on the underlying allochthons and basement is being studied in a section provided by two fully cored 2.5 km deep drill holes. These operational data sets concern the second drill site, COSC-2 (boreholes ICDP 5054-2-A and 5054-2-B), drilled from mid April to early August 2020. COSC-2 is located approximately 20 km eastsoutheast of COSC-1, close to the southern shore of Lake Liten between Järpen and Mörsil in Jämtland, Sweden. COSC-2 drilling started at a tectonostratigraphic level slightly below that at COSC-1’s total depth. It has sampled the Lower Allochthon, the main Caledonian décollement and the underlying basement of the Fennoscandian Shield, including its Neoproterozoic and possibly older sedimentary cover. COSC-2 A reached 2276 m driller's depth with nearly 100 % core recovery between 100 m and total depth. COSC-2 B, with a driller’s depth of 116 m, covers the uppermost part of the section that was not cored in COSC-2 A. The operational data sets include the drill core documentation from the drilling information system (mDIS), full round core scans, MSCL data sets, a preliminary core description and the geophysical downhole logging data that were acquired during and subsequent to the drilling operations. All downhole logs and core depth were subject to depth correction to a common depth master (cf. operational report for detailed information). The COSC-2 drill core is archived at the Core Repository for Scientific Drilling at the Federal Institute for Geosciences and Natural Resources (BGR), Wilhelmstr. 25–30, 13593 Berlin (Spandau), Germany.

A database of R-R-R triple junction analogue and numerical models

This dataset presents the raw data from two experimental series of analogue models and four numerical models performed to investigate Rift-Rift-Rift triple junction dynamics, supporting the modelling results described in the submitted paper. Numerical models were run in order to support the outcomes obtained from the analogue models. Our experimental series tested the case of a totally symmetric RRR junction (with rift branch angles trending at 120° and direction of stretching similarly trending at 120°; SY Series) or a less symmetric triple junction (with rift branches trending at 120° but with one of these experiencing orthogonal extension; OR Series), and testing the role of a single or two phases of extension coupled with effect of differential velocities between the three moving plates. An overview of the performed analogue and numerical models is provided in Table 1. Analogue models have been analysed quantitatively by means of photogrammetric reconstruction of Digital Elevation Model (DEM) used for 3D quantification of the deformation, and top-view photo analysis for qualitative descriptions. The analogue materials used in the setup of these models are described in Montanari et al. (2017), Del Ventisette et al. (2019) and Maestrelli et al. (2020). Numerical models were run with the finite element software ASPECT (e.g., Kronbichler et al., 2012; Heister et al., 2017; Rose et al., 2017).

A database of analogue models testing the interaction between magmatic intrusion-related doming and caldera collapse

This dataset presents the raw data from one experimental series (named CCEX, i.e., Caldera Collapse under regional Extension) of analogue models performed to investigate the process of caldera collapse followed by regional extension. Our experimental series tested the case of perfectly circular collapsed calderas afterward stretched under regional extensional conditions, that resulted in elongated calderas. The models are primarily intended to quantify the role of regional extension on the elongation of collapsed calderas observed in extensional settings, such as the East African Rift System. An overview of the performed analogue models is provided in Table 1. Analogue models have been analysed quantitatively by means of photogrammetric reconstruction of Digital Elevation Model (DEM) used for 3D quantification of the deformation, and top-view photo analysis for qualitative descriptions. The analogue materials used in the setup of these models are described in Montanari et al. (2017), Del Ventisette et al. (2019), Bonini et al., 2021 and Maestrelli et al. (2021a,b).

A database of enhanced-gravity analogue models examining the influence of pre-existing fabrics on the evolution of oblique rift

This dataset shows the original data of a series of enhanced-gravity (centrifuge) analogue models, which were performed to test the influence of the pre-existing fabrics in the brittle upper crust on the evolution of structures resulting from oblique rifting. The obliquity of the rift (i.e., the angle between the rift axis and the direction of extension) was kept constant at 30° in all the models. The main variable of this experimental series was the orientation of the pre-existing fabrics (indicated as the angle between the trend of the fabric and the orthogonal to extension), which varied from 0° to 90° (i.e., from orthogonal to parallel to the extension direction). The inherited discontinuities were reproduced by cutting with a knife through the top brittle layer of models. An overview of the experimental series is shown in Table 1. In this dataset, four different data types are provided for further analysis: 1) Top-view photos of model deformation, taken at different time intervals and showing the deformation process of each model; they can be used to interpret the geometrical characteristics of rift-related faults; 2) Digital Elevation Models (DEMs) used to reconstruct the 3D deformation of the analogue models, allowing for quantitative analysis of the fault pattern. 3) Movies of model deformation, built from top-view photos, which help to visualize the evolution of model deformation; 4) Faults line-drawings to be used for statistical quantification of rift-related structures. Further information on the modelling strategy and setup can be found in the publication associated to this dataset and in Corti (2012), Philippon et al. (2015), Maestrelli et al. (2020), Molnar et al. (2020), Zwaan et al. (2021), Zou et al. (2023). Materials used to perform these enhanced-gravity analogue models were described in Montanari et al. (2017), Del Ventisette et al. (2019) and Zwaan et al. (2020).

Compilation of GEOROC Mineral Compositions filtered by the MIST (Mineral Identification by Stoichiometry) Algorithm

The GEOROC database includes helpful compilations of mineral compositions aggregated from measurements reported in decades worth of publications, but it can be challenging to consistently filter mislabeled, inaccurate, or incomplete mineral compositions. MIST (Mineral Identification by Stoichiometry) is a stoichiometry-based computational algorithm that identifies geochemical observations with normalized elemental ratios matching natural minerals. The stoichiometric filters that were manually coded in MIST for over 240 mineral species are based on reported mineral formulas and well-documented examples of mineral chemistry reported in RRUFF and associated databases, typically including a ~5-10% tolerance in stoichiometric ratios based on measurement errors, vacancies, and substitutions. The MIST model can therefore efficiently filter the GEOROC mineral compilation files to recognize compositions whose normalized oxides match the labeled mineral stoichiometry. Furthermore, the MIST output includes results of intermediate data manipulation steps, a detailed stoichiometric formula for each input composition, and consistently calculated mineral endmembers such as Fo, En, Ws, and Fs. MIST is agnostic to the instrument used to collect oxide data. Because MIST uses normalized oxides, it cannot distinguish between some mineral species, where applicable, they are reported as a group (e.g., gypsum/bassanite/anhydrite). MIST can only recognize minerals encoded in the algorithm, so other real but less common minerals will not be recognized. The full list of minerals MIST can recognize, along with more details of the algorithm and results pages, are published in Siebach et al. (https://doi.org/10.1016/j.cageo.2025.106021). This dataset includes fifteen of the Compiled Mineral files published by GEOROC in 12-2024 including the MIST results (whether or not a species was confirmed by MIST). Prior to running the data through MIST, all files were filtered to only include mineral compositions that included major oxides (e.g., silicate mineral compositions where SiO2 > 0 wt%). Furthermore, all variations of reported Fe were collapsed into a single column representing FeOT. Metadata is preserved from the original compiled GEOROC files, so users may add additional filters as appropriate for different purposes. Results have not been filtered for reported sum of total oxides, but doing so can help identify particular mineral species (e.g., separate gypsum from bassanite). An additional file preserves the full reference information for each mineral compilation. We suggest using the compositions that MIST identifies as stoichiometrically consistent with a mineral species as a standardized filter on the GEOROC datasets prior to utilizing the data in machine learning models or similar applications. These may also be helpful any time a user would like standardized formulas or mineral endmember information for these mineral compilations.

A database of caldera collapse analogue models stretched under extensional conditions

This dataset presents the raw data from one experimental series (named CCEX, i.e., Caldera Collapse under regional Extension) of analogue models performed to investigate the process of caldera collapse followed by regional extension. Our experimental series tested the case of perfectly circular collapsed calderas afterward stretched under regional extensional conditions, that resulted in elongated calderas. The models are primarily intended to quantify the role of regional extension on the elongation of collapsed calderas observed in extensional settings, such as the East African Rift System. An overview of the performed analogue models is provided in Table 1. Analogue models have been analysed quantitatively by means of photogrammetric reconstruction of Digital Elevation Model (DEM) used for 3D quantification of the deformation, and top-view photo analysis for qualitative descriptions. The analogue materials used in the setup of these models are described in Montanari et al. (2017), Del Ventisette et al. (2019), Bonini et al., 2021 and Maestrelli et al. (2021a,b).

Compilation of palaeomagnetic data from sediments and volcanic rocks spanning 30,000 to 50,000 years ago used to create the temporally continuous global spherical harmonic geomagnetic field model LSMOD.1

Compilation of palaeomagnetic data from sediments and volcanic rocks from 68 sites spanning 30,000 to 50,000 years ago used to create the temporally continuous global spherical harmonic geomagnetic field model LSMOD.1. This is in supplement to the paper "Earth's magnetic field is (probably not reversing" (Brown et al. 2018)A description of how the data were treated is given in SI Appendix of the associated publication. A full list of complementary data sources (references) is given is provided with the data.-----------------For the volcanics there is one filevolc.txtThe headers are:Age[ka] - age in thousands of years before present (0 = 1950 AD).Error[ka] - uncertainty on the age.Lat[Deg] - Latitude of site in degrees.Lon[Deg] - Longitude of site in degrees.Dec[Deg] - Declination in degrees.Inc[Deg] - Inclination in degrees.Alpha95[Deg] - 95% circular confidence limit on the directional data.F[microT] - intensity in micro Tesla.F_Error[microT] - uncertainy on the intensity in micro Tesla.-9999 - no data-----------------For the sediments there are two types of files, those that end *.txt and those that end *int.txt.*.txt - directional data with the headers:Age[ka] - age in thousands of years before present (0 = 1950 AD).Lat[Deg] - Latitude of site in degrees.Lon[Deg] - Longitude of site in degrees.Dec[Deg] - Declination in degrees.Inc[Deg] - Inclination in degrees.-9999 - no data*int.txt - scaled intensity data using PADM2M (as described in Section S1.3 of SI Appendix)Age[ka] - age in thousands of years before present (0 = 1950 AD).Lat[Deg] - Latitude of site in degrees.Lon[Deg] - Longitude of site in degrees.F[microT] - Scaled intensity in micro Tesla.6 of the sediment data sets are individual records (BLS, CHI, MIN, PYR, SIO, S01).6 of the sediment data sets are stacks of records (BBS, NAS, NPS, OBS, SBS, SAS).All details of the records are given in Table S1 and Table S2 of the SI Appendix of the associated publication.

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