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Found 196 results.

OGS Core Logging Lab - logging sediment cores in Lago Argentino (Brazo Sur), Argentina

The spectacular water outburst occurring semi-periodically when the ice-dam formed by the external front of the Perito Moreno glacier collapses, is one of the most attracting events in the UNESCO ‘Parque Nacional Los Glaciares’ of southern Patagonia. These occurrences have been documented since 1936. Instead, evidence of previous events has been only indirectly provided by dendrochronology analysis. Four sediments cores have been collected on coastal soil in 2017, analysed by X rays, HR photography and Magnetic Susceptibility. The radiographies of these cores allowed to identify lake floodings deposits due to glacier readvance over the coastal soil related to the collapse of the Perito Moreno ice-dam. In November 2018, 10 undisturbed sediment gravity cores were collected within a small inlet of Brazo Sur, that is, the southern arm of Lago Argentino, at water depths ranging from 10 to 6 m using a 4.5 cm diameter gravity corer ‘KC Kajak Sediment Sampler’ Model 13.030. The length of these cores varies from 45 to 65 cm. X rays, HR photography and magnetic susceptibility provide the first evidence of an abrupt change in the stratigraphic record found at variable depths of 14–18 cm from the top of the cores, marked by a hiatus spanning ca. 3200 years, separating planar-laminated sediments below from an alternation of erosional and depositional events above it, indicating recurring high-energy conditions generated by the emptying of the lake basin, as well as ash layers observed in the longest cores. Radio carbon data collected on three of these cores record ice-daming in the Little Ice age, at 324-266 cal yrs BP. These well-preserved stratigraphic records highlight the key role of glaciolacustine deposits in reconstructing the glacial dynamics and palaeoclimate evolution of a glaciated region.

Ring-shear test data of quartz sand SIBELCO S80 used for analogue modelling in the Tectonic Laboratory (TecLab) at Utrecht University

This dataset provides friction data from ring-shear tests on quartz sand SIBELCO S80 used in analogue modelling of tectonic processes as a rock analogue for the earth’s upper crust (e.g., Klinkmüller et al., 2016). According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of quartz sand S80 are µP = 0.75, µD = 0.59, and µR = 0.69, respectively (Table 5). Cohesion of the material ranges between 0-80 Pa. The material shows no rate-dependency (<1% per ten-fold change in shear velocity v). The tested bulk material consists of quartz sand SIBELCO S80 with grain size of ~0.63-355 µm (D50 = 175 µm. Bulk and grain densities are 1300 kg/m³ and 2650 kg/m³, respectively and the hardness is 7 on Moh’s scale. S80 is sold e.g., by the company SIBELCO (sibelco.com).

Petrological, geochemical and isotopic characterization of kamafugites from East-Central Africa, Italy and Brazil: a review

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.

Europaeischer Pool Informations- und Schulungsmaterialien Solartechnik (EUPOS)

Ring-shear test data of wallnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing))

This dataset provides friction data from ring-shear tests walnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the tested materials behave as a Mohr-Coulomb material characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.90, µD = 0.63, and µR = 0.68, respectively (Table 4). Cohesion of the material ranges between 0-40 Pa. The tested bulk material consists of walnut shells with grain size of 180-380 µm (Table 1) and is sold under the name "Walnut Shells" with the product number YR-98547 by the company Yiran Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of mica used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing)

This dataset provides friction data from ring-shear tests black mica used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.59, µD = 0.56, and µR = 0.57, respectively (Table 4). Cohesion of the material ranges between 100-130 Pa. The tested bulk material consists of black mica (Biotite) with grain size of 380-830 µm and is sold under the name "Black Mica" with the product number YS-004 by the company Yunshi Building Materials Co., Ltd (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of foamglass used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing)

This dataset provides friction data from ring-shear tests foamglass used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.55, µD = 0.52, and µR = 0.57, respectively (Table 4). Cohesion of the material ranges between 10-30 Pa. The tested bulk material consists of foamglass with grain size of 180-380 µm (Table 1) and is sold under the name "Floating Bead" with the product number PZ-002 by the company Tuyun Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of colored quartz sand used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing)

This dataset provides friction data from ring-shear tests colored quartz sand used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.75, µD = 0.59, and µR = 0.67, respectively (Table 5). Cohesion of the material ranges between 20-90 Pa. The tested bulk material consists of blue colored quartz sand with grain size of 180-380 µm and is sold under the name "Colored Sand" with the product number A1 by the company Xinran Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experi-ments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and vol-ume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of white mica used for analogue modelling in the Tectonic Laboratory (TecLab) at Utrecht University

This dataset provides friction data from ring-shear tests white mica (Muscovite) used for analogue modelling in the Tectonic Laboratory (TecLab) at Utrecht University. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of white mica sand are µP = 0.60, µD = 0.56, and µR = 0.55, respectively (Table 5). Cohesion of the material ranges between 140-180 Pa. The tested bulk material consists of white mica (Muscovite) with grain sizes ranging from 45-600 µm with the following distribution: 45-106µm – 10-25%, 106-425µm – 65-85%, 425-600µm – <2.5%.

Digital Volume Correlation (DVC) data from an analogue experiment exploring kinematic coupling of brittle and viscous deformation

This dataset includes volumetric data sets from a Digital Volume Correlation (DVC) analysis for recreating images of a re-analyzed analogue models previously presented in (Zwaan et al., 2018). Using a brittle-viscous two-layer setup, this experiment focused on the evolution of a rift-pass structure. On top of the viscous layer, two viscous seeds are placed with a right-stepping stair-case offset to simulate two propagating rift segments, confining a central rift-pass block (Fig. 1). The selected model was analyzed by means of Digital Volume Correlation (DVC) applied on X-Ray computed tomography (XRCT) volumes. The data set includes DVC data in the form of .mat files for incremental (i.e., 20 min intervals) and cumulative displacement components. In addition, this dataset provides a MATLAB script for 1) recreating volumetric displacement sets of subsequent time steps 2) calculating finite stretches and 3) rigid-body rotations. The used experiment was performed at the Tectonic Modelling Laboratory of the University of Bern (UB). DVC analysis was performed at the Royal Holloway University London (RHUL). The model consists of a two-layer brittle-viscous set up with a total thickness of 8 cm and the set up lies on top of a 5 cm thick foam-plexiglass base with a length and width of 800 mm by 305 mm, respectively. Before model construction, the foam-plexiglass assemblage is placed between longitudinal side walls and expands during the course of the experiment as the mobile sidewalls move apart. The applied divergence velocity is 7.5 mm/h and with has an orthogonal direction with respect to the viscous seeds. This results in a maximum displacement of 30 mm after a total run time of 4h. Detailed descriptions of the experiment, mechanical properties as well as monitoring techniques can be found in Schmid et al. (2024).

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