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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).

Analogue modeling results showing fault network evolution during multiphase triaxial strain

This data set includes the results of high-resolution digital image correlation (DIC) analysis and digital elevation models (DEM) applied to analogue modelling experiments (Table 1). Six generic analogue models are extended on top of a rubber sheet. In Series A, as extension velocity increases, the initial biaxial plane strain condition evolves into triaxial constrictional or intermediate strain. Models A1 and A2 are two-phase models and Model A3 is a three-phase model. Conversely, in Series B, as extension velocity decreases, the model starts with triaxial constrictional strain and ends up with biaxial plane or intermediate triaxial strain. Models B1and B2 are two-phase models and Model B3 is a three-phase model. Detailed descriptions of the experiments can be found in Liu et al. (2025) to which this data set is supplement. The data presented here are visualized as topography, the horizontal cumulative surface strain, and incremental profiles.

Digital Image Correlation data from experiments of releasing bend evolution within different strength wet kaolin

The data set includes the Digital Image Correlation (DIC) results for four experiments of releasing bends along dextral strike-slip faults that were performed at the University of Massachusetts at Amherst (USA). Gabriel et al. (in prep.) used the DIC data sets to investigate how releasing bend fault systems evolve within different strength wet kaolin. Information on the experimental set up and methods can be found in the main text and supplement to Gabriel et al. (in prep.). The data here include the incremental displacement time series, strain animation and surface elevation data at the end of the two experiments with different clay strength, which are presented within Gabriel et al. (in prep). We also include in this data repository incremental displacement time series and strain animations from two experiments that repeat the conditions of the experiments featured in Gabriel et al. (2025).

Cathodoluminescence zoning images of Lower El Cajete quartz and sanidine crystals, Valles Caldera, New Mexico, USA

The Valles Caldera, New Mexico, USA was created by two caldera-forming eruptions at ~1.6 and ~1.1 Myr. Since then, post-caldera activity has consisted of lava domes, lava flows, large explosive phases, and a hydrothermal system active today. Possibly the youngest eruption sequence, El Cajete, was emplaced 74.4 ± 1.3 ka (Zimmerer et al., 2016) and began with pyroclastic surges, followed by pyroclastic density currents (PDCs) and pumice-rich Plinian pyroclastic fall (Self et al., 1988). The objective of this project was to characterize crystal grains from the early El Cajete sequence, in terms of morphology and textures, using scanning electron microscopy (SEM). The early El Cajete differs from the later part of the sequence in its greater stratigraphic and lithologic complexity, having been formed from not only pyroclastic fall (like the later El Cajete) but also surge beds and PDCs. This dataset was collected under the national open access action at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Pisa SEM/EDS facility supported by WP3 ILGE – MEET project, PNRR – EU Next Generation Europe program, MUR grant number D53C22001400005. This allowed me to obtain the present dataset of 31 cathodoluminescence (CL) images of 30 quartz crystals and one sanidine crystal.

40Ar/39Ar Radiometric Dating of Quaternary Basaltic Volcanism at the Kula Volcanic Province, Western Türkiye

During this research at the 40Ar-39Ar Geochronology Laboratory, CNR, Pisa, Italy, the analysis focused on 40Ar- 39Ar radiometric dating to investigate three distinct periods of volcanism from the Kula Volcanic Province in western Türkiye. This area is a monogenetic volcanic field (MVF) and exhibits three eruptive periods in the Quaternary Period. The three periods of volcanism are named the Burgaz (first stage), the Elikcitepe (second stage), and the DivilitTepe (third stage). This type of volcanism is poorly understood due to their small eruption size and limited material, lack of suitable datable material, and short eruption duration, with geological histories often poorly constrained. The data publication includes data of four samples from the three different eruptive phases that were analysed, including one from the first stage, one from the second stage, and two from the third stage. The samples were successfully dated and gave ages as the Early Pleistocene (first stage), the Middle Pleistocene (second stage) and the Holocene (third stage). The data from this work will be used as part of a PhD thesis. The ages will be integrated into a more detailed geochemical analysis and facilitate a detailed examination of the temporal and spatial relationships for the evolution of the volcano, and insights into the mechanisms driving volcanic activity in the region. Data was acquired by an ARGUS VI multi-collector noble gas mass spectrometer, using the step-heating process for all samples. Between 9.9 and 11.1 mg of groundmass material was analysed.

Mechanical data of rotary shear experiments in bituminous dolostones

Mirror-like Surfaces (MSs) are ultra-polished fault surfaces widespread in carbonate seismic terrains, but their formation process is still debated. We deformed gouge samples from exposed fault surfaces hosted in bituminous dolostone rocks in a rotary shear apparatus (SHIVA) at seismic slip rates (1 m/s). By changing the water availability (water-pressurised and room-humidity conditions) and the organic matter/dolomite content (> 35%, dark gouge DG; < 30% bright gouge BG) we investigated the mechanical behaviour leading to MSs formation in fault gouges. We run tests at 15 MPa effective normal stress, 2 MPa confinement and 1 MPa pore pressure for the water-pressurised experiments and a total displacement of 0.13 m. Mirror-like fault surfaces were obtained in all successful experiments; mirrors were more developed under room-humidity conditions. Bituminous dolostones under room-humidity conditions had a slip neutral behaviour with a low friction (0.3). Bituminous dolostones under water-pressurised conditions showed a slip weakening behaviour with an initial peak effective friction μp = 0.65, followed by a drop to effective friction μss DG than in BG (i.e., μss of 0.25 vs 0.28). Future work will focus on the microstructural analysis of the experimental products and the investigation of the slip behaviour of bituminous dolostones at sub-seismic slip rates for a complete study of the slip behaviour spectra. This publication results from work conducted under the national open access action at SHIVA (Slow to High Velocity Apparatus) - HP-HT laboratory of experimental Volcanology and Geophysics (INGV, Roma 1 section) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.

Stable Nitrogen isotope composition of common wheat in intercropping with Persian clover (Tuscany, Italy)

Intercropping is the simultaneous growth of two or more crops in the same space for a significant part of their life cycle (Willey, 1979). In this context, samples from one farm experiments in the growing season 2015/2016 and 2016/2017, embedded in the cropping systems of one arable farm in the surrounding of Pisa, central-western part of Italy, were collected for analysis. The treatments were: PCW, a temporary intercropping system of wheat and persian clover, sown in paired rows; CONTROLSTRIP, unfertilized wheat as a sole crop, sown in paired rows.

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).

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