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Kamafugites are 'exotic igneous rocks' with mineralogical and chemical compositions that differ from those observed in common magmas. Despite their importance, kamafugites are still a poorly constrained topic and they lack a general petrological model due to their variable petrographic, geochemical and isotopic features. A detailed comparison among kamafugites is necessary to obtain a deeper understanding of the processes involved in their petrogenesis and of their strongly metasomatised mantle sources. Therefore, this data publication doesn’t only provide new geochemical and isotopic data from kamafugites, but a comprehensive data compilation for kamafugite samples in the Western branch of the East Africa Rift (WEAR) in Uganda and Democratic Republic of Congo, the Intra-Apennine Province (IAP), as well as for the Alto Paranaiba (APIP) and Goiás (GAP) provinces in Brazil. 97 kamafugite whole-rock data for the WEAR, 42 for IAP and 51 for APIP and GAP have been collected and compared to highlight similarities and differences, aiming to reconstruct their petrogenesis. The new data in this data publication results from work conducted at Laboratory of Geochronology and Radiogenic Isotope Geochemistry - Pisa1 (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
This dataset is supplemental to the paper Wallis et al. (2021) and contains data on dislocations and their stress fields in olivine from the Oman-UAE ophiolite measured by oxidation decoration, electron backscatter diffraction (EBSD) and high-angular resolution electron backscatter diffraction (HR-EBSD). The datasets include images of decorated dislocations, measurements of lattice orientation and misorientations, densities of geometrically necessary dislocations, and heterogeneity in residual stress. Data are provided as 6 TIF files, 8 CTF files, and 37 tab-delimited TXT files. Files are organised by the figure in which the data are presented in the main paper. Data types or sample numbers are also indicated in the file names.
The study of textural and chemical characteristics of mafic minerals from mantle xenoliths is essential to investigate the nature of the upper mantle in a continental geodynamic context, melts generation and their effects related to mantle metasomatism. Particular textures in mantle minerals, inclusions or secondary veins of different nature (silicates vs carbonates), bubbles, represent petrographic tools to investigate these processes within the mantle. Petrographic 2D thin sections might overlook these mineralogical features, and 3D textural analysis through X-ray computed microtomography (micro-CT) are crucial to overcome these limitations. We focused on the Mt. Vulture volcano (southern Italy) rare mantle xenoliths, brought to the surface by a melilitite-carbonatite magma (141 ka), with particular emphasis to spinel-wehrlite xenoliths and wehrlitization processes that is located close to an area of intense CO2 degassing associated to catastrophic earthquakes. Preliminary results showed interesting 3D textural distributions within the studied xenoliths-forming mantle minerals. In particular, the micro-CT allowed to furnish new constrains on the relationship between fluids entrapment and migration, and structural discontinuities. Indeed, some minerals (especially those from the wehrlite xenoliths) showed a well-correlated distribution of fluid inclusions along the secondary fracturing planes. This publication results from work conducted under the transnational access/national open access action at Istituto Nazionale di Geofisica e Vulcanologia – Osservatorio Vesuviano (INGV-OV) and supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005. The author thanks also Gianmarco Buono and Lucia Pappalardo for their support during the analyses and the post processing process.
This dataset provides rheometric data of three viscous materials used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Earth Sciences Department of the University of Florence (Italy). The first material, PP45, is a mixture of a silicone (Polydimethylsiloxane or PDMS SGM36) and plasticine (Giotto Pongo). The PDMS is produced by Dow Corning and its characteristics are described by e.g. Rudolf et al. 2016a,b). Giotto Pongo is produced by FILA (Italy). Both components are mixed following a weight ratio of 100:45, and the final mixture has a density of 1520 kg m3. The second material, SCA705 is a mixture of Dow Corning 3179 putty, mixed with fine corundum sand and oleic acid with a weight ratio of 100:70:05 and a resulting density of 1660 kg m3. The final material, SCA7020 consists of the same components as SCA705, but with a slightly higher oleic acid content reflected in the weight ratio of 100:70:20. The mixture’s density is 1620 kg m3. The material samples have been analyzed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (20˚C). Rotational (controlled shear rate) tests with shear rates varying from 10-4 to 1 s-1 were performed. Additional temperature tests were run with shear rates between 10-2 to 10-1 s-1 for a temperature range between 15 and 30˚C. According to our rheometric analysis, the materials all exhibit shear thinning behavior, with high power law exponents (n-number) for strain rates below 10-2s-1, while power law exponents are lower above that threshold.For PP45, the respective n-numbers are 4.8 and 2.6, for SCA705 6.7 and 1.5, and for SCA7020 9.1 and 2.0. The temperature tests show decreasing viscosities with increasing temperatures with rates of -3.8, -1.4 and -1.9% per ˚K for PP45, SCA705 and SCA7020, respectively. An application of the materials tested can be found in Zwaan et al. (2020).
Gelatin is a versatile material commonly used in analogue modelling because of its complex rheology, which allows simulating a wide range of tectonic processes requiring either elastic (e.g., dyke intrusions models) and viscoelastic behavior (e.g., analog earthquakes models). Salt (NaCl) is generally added to gelatin to improve the scaling of the models by increasing the density of the material. The addition of salt results also in a weakening of the gelatin structure, which in turn can dramatically affect its rheological properties. Here, we provide raw data of rheometric measurements performed to test the rheological properties of type A (pig-skin) 2.5 wt% gelatin at T=10°C as a function of salt concentration and ageing time. Each sample was analyzed using dynamical oscillation tests (i.e., amplitude, frequency and time sweep tests) in shear strain controlled mode. All details about sample preparation procedure, measuring protocol, as well as results and data interpretation can be found in Brizzi et al. (2016).The data are provided as Excel files in *.xlsx format and comma-separated files in *.csv format. Each contains multiple measurements. In the Excel files, each measurement is presented as a table in different spreadsheets. In the comma-separated files, each measurement start with its own data series information, followed by the actual data. All files can be opened using MS Excel or equivalent software. An overview of tested salt concentrations and performed measurements can be found in the Explanation_Brizzi_et_al_2016.pdf file. A full list of the files included is given in List_of_files_Brizzi_et_al_2016.pdf.
This dataset includes raw data used in the paper by Reitano et al. (2022), focused on the effect of imposed boundary conditions (regional slope and rainfall rate) on the morphological evolution of analogue landscapes; the paper also focuses on applicability of stream power laws on analogue models, defining if and how the parametrization used in natural landscapes works in analogue ones. The experiments have been carried out at Laboratory of Experimental Tectonics (LET), University “Roma Tre” (Rome). Detailed descriptions of the experimental apparatus and experimental procedures implemented can be found in the paper to which this dataset refers. Here we present: • Pictures recording the evolution of the models. • GIFs showing time-lapses of models. • Raw DEMs of the models, used for extracting data later discusses in the paper. • Raw channels data (.mat files).
This dataset provides rheometric data of silicone (Polydimethylsiloxane, PDMS SGM36)-corundum sand mixtures used for analogue modelling in Zwaan et al. (2016, 2017), Zwaan and Schreurs (2017) and in the Tectonic Modelling Lab of the Institute of Geological Sciences at the University of Bern (CH). The PDMS is produced by Dow Corning and its characteristics have been described by e.g. Rudolf et al. (2016a,b). The corundum sand (Normalkorund Braun 95.5% F120 by Carlo Bernasconi AG: https://www.carloag.ch/shop/catalog/product/view/id/643), has a grainsize of 0.088-0.125 mm and a specific density of 3.96 g cm^-3. Further rheological characteristics are described by Panien et al. (2006). The density of the tested materials ranges between 1 (pure PDMS) and 1.6 g cm^-3 (increasing corundum sand content in mixture). The material samples have been analysed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature. Rotational (controlled shear rate) tests with shear rates varying from 10^-4 to 10^-1 s^-1 were performed.According to our rheometric analysis, the material is quasi Newtonian at strain rates below 10^-3*s^-1 and weakly shear rate thinning above. Viscosity and stress exponent increase systematically with density from ~4*10^4 to ~1*10^5 Pa*s and from 1.06 to 1.10, respectively. A first application of the materials tested can be found in Zwaan et al. (2016). Detailed information about the data, methodology and a list of files and formats is given in the "data description" and "list of files" that are included in the zip folder and also available via the DOI landing page.
This dataset provides the surface velocity fields derived with MatPIV (open-source Matlab toolbox for Particle Image Velocimetry; Sveen 2004) of three seismotectonic analog models (e.g., Rosenau et al., 2017) performed to investigate the role of geometry and friction of a single subducting seamount on the seismogenic behavior of the megathrust. Model 1 has a seamount covered by sandpaper (i.e., high friction) that is placed at 1/2 of the trench-parallel length of the seismogenic zone. Model 3 has the same geometry of model 1, but the seamount is in direct contact with the gelatin (i.e., not covered by sandpaper, hence low friction). Model 5 has a low friction patch (i.e., no geometry) that is placed again at 1/2 of the trench-parallel length of the seismogenic zone. Together with the surface velocity fields, we also provide Matlab scripts for visualization. A more detailed description of the experimental setup, configuration of the models and materials can be found in Menichelli et al. (submitted), to which this dataset is supplementary. Our seismotectonic models represent a downscaled subduction zone (1 cm in the model corresponds to 6.4 km in nature; Rosenau et al., 2017). The experimental setup consists of a 60 x 34 cm2 Plexiglass box with a 10°-dipping aluminum basal plate that moves downward with a constant velocity of 0.01 cm/s, analog of the subducting plate. The overriding plate is represented by an elastic wedge of 2.5 wt% pigskin gelatin at T = 10 °C (Di Giuseppe et al., 2009). The seismogenic zone of the megathrust is simulated using a rectangular sandpaper patch (Corbi et al., 2013), with a downdip width of 16 cm and located 31 and 47 cm from the backstop. This corresponds to a 100-km-wide seismogenic zone extending over a depth interval between 15 and 34 km. The updip and down dip aseismic regions of the megathrust are simulated by plastic sheets that are fixed on the setup frame and not subject to subduction (Corbi et al., 2013). A 3D-printed PLA seamount is placed on the seismogenic zone (e.g., Van Rijsingen et al., 2019). The seamount has a height of 6.28 mm and a diagonal length of 94 mm, corresponding to 4 km and 60 km in nature, respectively. These dimensions scale well-known seamounts, such as the Joban Seamount chain in the Japan Trench or the Louisville seamount chain in the Tonga-Kermadec Trench. Experiments were monitored with a CCD camera that acquired a sequence of high-resolution top-view images (1600 x 1200 pixels2, 8 bit, 256 gray levels) at 7.5 fps for the entire duration of the experiment (i.e., ca. 24 minutes). Images are processed with Particle Image Velocimetry (PIV; Adam et al., 2005) using the open-source Matlab toolbox MatPIV (Sveen, 2004). MatPIV provides the velocity field between two consecutive frames, measured at the surface of the model. The velocity field was then used as input to identify analog seismic events using the open-source Matlab function findpeak. The threshold used was 0.1 cm/s. Once earthquakes were identified, we derived their source parameters such as seismic slip, magnitude, and recurrence time following Corbi et al. (2017) and van Rijsingen et al. (2019).
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