Other language confidence: 0.9258606541267423
The data set contains stress-strain data of Carrara marble experimentally deformed in triaxial compression at temperatures of 20 – 800°C, confining pressures of 30 – 300 MPa, and strain rates between 10-3 and 10-6 s-1. This range covers conditions, at witch marble deforms in the semi-brittle regime, i.e., strength depends on all parameters, but with different sensitivity. Semi-brittle deformation behavior is expected to be important in the mid continental crust. The experiments were conducted in the Experimental Rock Deformation Laboratory of the GFZ German Research Centre for Geosciences in Potsdam, Germany. The data are separated into 91 individual ASCII files, one for each sample. The corresponding temperature, pressure and strain rate conditions are listed in Tab. 1. of the data description and in the associated work by Rybacki et al. (submitted).
The southern Andes are regarded as a typical subduction orogen formed by oblique plate convergence. Despite decades of studies, there is considerable uncertainty as to how deformation is kinematically partitioned in the upper plate. Using scaled analogue experiments modelling, we test the concept of dextral transpression for this orogen. We advocate that the GPS velocity field portrays interseismic deformation related to deformation of strong crust north, and weak crust south, of 37°S. Contrary to the popular hypotheses that the Liquiñe-Ofqui Fault Zone, a prominent intra-arc deformation zone, takes up most of the plate boundary-parallel dextral strike-slip, we find that dextral transpression affects the entire model orogen through tectonic segmentation of crust. Moreover, prominent, regularly spaced sinistral oblique-slip thrust faults, interpreted as antithetic Riedel shears, developed spontaneously in all of our experiments and call into question the general believe that their NW-striking natural equivalents formed from pre-Andean discontinuities. Our experiments prompt us to reconsider the apparently well-established geodynamic concept that strain and margin-parallel displacement is localized on a few margin-parallel faults in the southern Andes.
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).
Data supporting the publication Hornby, AJ, Kueppers U, Maurer BM, Poetsch C and Dingwell DB (2020) "Experimental constraints on volcanic ash generation and clast morphometrics in pyroclastic density currents and granular flows". In this study, fine ash is generated from lapilli-sized volcanic pumice and scoria in rotary tumbler experiments. We seek to explore ash production processes and clast attrition in natural PDCs, and gain insight into the controlling parameters for particle production efficiency with PDC transport distance. We vary the starting mass, apparatus size, and material properties and tumble clasts over multiple transport distance steps from 0.2-6 km. The data are provided in ASCII or image formats as one zipped folder (2020-025_Hornby-et-al_data.zip) and organised in the following sub-folder structure (for more information please consult the associated data description and Hornby et al (2020): (1) Experimental methods, apparatus and data collections (2) Ash generation data for tumbling experiments (3) Laser particle size distribution data for ash generated in tumbling experiments (4) Post-experimental lapilli size (generated via 3-axis caliper measurements), mass, bulk density and dense rock equivalent (DRE) porosity results (5) 2D image analysis morphology results (6) 2D image analysis size results (7) Cropped, scaled and thresholded images lapilli used for morphometric analysis (8) Image analysis macros and workflow for ImageJ (9) Integrated analysis of results This project has received funding from the European Union's Horizon 2020 research and innovation programme.
This dataset provides results from rheological tests of glucose syrup from two suppliers tested within the EPOS Multi-scale Laboratories (MSL) trans-national access (TNA) program 2019 at the Laboratory of Experimental Tectonics (LET), Univ. Roma TRE, Italy. Syrups Glucowheat 45/81 (GW45) and Glucowheat 60/79 (GW60) are produced by Blattmann Schweiz AG, Switzerland (2019 batch). Syrups GlucoSweet 44 (GS44) and GlucoSweet 62 (GS62) are produced by ADEA (Amidi Destrini ed Affini), Italy (2019 batch) . The four tested glucose syrups are labeled according to their DE value (dextrose equivalent value). For tested products from Blattmann Schweiz AG, the second number refers to the weight percentage of dry substance. Glucose syrup GS44 is used in full lithospheric scale analogue experiments at the Tectonic Modelling Lab (TecLab) at the University of Bern, Switzerland as a low-viscosity material simulating the asthenospheric mantle lithosphere to provide isostatic equilibration. The materials have been analyzed using a MCR301 Rheometer (Anton Paar) equipped with parallel plates geometry and rotational regime . To prevent the evaporation of the samples during the measurements, an external water-lock device has been used.
This data set includes overviews depicting the surface evolution (time-lapse photography, topography analysis, digital image correlation [DIC] analysis), as well as and progressive physical cross-section analysis of 18 laboratory experiments (analogue models) testing the influence of rheologically weak layers (i.e. layers with [a component of] viscous behaviour) and basal fault kinematics on deformation in the weak layer’s overburden. This model set-up was inspired by the geological situation in the Swiss Alpine Foreland. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). Detailed descriptions of the model set-up preparation and results, as well as the monitoring techniques can be found in Zwaan et al. (in review).
This data set includes 40 videos (+ 1 image) depicting the surface evolution of 39 experiments on crustal extension, as well as 4D CT imagery (figures and videos) of 6 of these experiments. The experiments examined the influence of the method for driving extension (foam base, rubber base, plate base or conveyor base) for localization of deformation in overlying layers of brittle-only and brittle-viscous materials representing the earth’s crust. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern. Detailed descriptions of the experiments and monitoring techniques can be found in Zwaan et al. (2019) to which these data are supplementary material.All experiments were monitored with top view photographs (SLR camera Nikon D-100 6.1 MPx). The photograph time steps depend on the applied extension velocity, but are generally 1 or 2 min. Six experiments were also monitored with an X-Ray computed tomography technique using a 64 slice Siemens Somatom Definition AS X-ray CT-scanner (Zwaan et al., 2016) with varying time intervals (5-30 min). CT-data was analyzed with the software OsiriX (Pixmeo SARL).
This data set provides two series of experiments from ring-shear tests (RST) on glass beads that are in use at the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam. The main experimental series contains shear experiments to analyse the slip behaviour of the granular material under analogue experiment conditions. Additionally, a series of slide-hold-slide (SHS) tests was used to determine the rate and state friction properties. A basic characterisation and average friction coefficients of the glass beads are found in Pohlenz et al. (2020). The glass beads show a slip behaviour that is depending on loading rate, normal stress and apparatus stiffness which were varied systematically for this study. The apparatus was modified with springs resulting in 4 different stiffnesses. For each stiffness a set of 4 experiments with different normal stresses (5, 10, 15 and 20 kPa) were performed. During each experiment loading rate was decreased from 0.02 to 0.0008 mm/s resulting in 9 subsets of constant velocity for each experiment. We observe a large variety of slip modes that ranges from pure stick-slip to steady state creep. The main characteristics of these slip modes are the slip velocity and the ratio of slip event duration compared to no slip phases. We find that high loading rates promote stable slip, while low loading rates lead to stick-slip cycles. Lowering the normal stress leads to a larger amount of creep which changes the overall shape of a stick-slip curve and extends the time between slip events. Changing stiffness leads to an overall change in slip behaviour switching from simple stick-slip to more complex patterns of slip modes including oscillations and bimodal slip events with large and small events. The SHS tests were done at maximum stiffness and higher loading rates (>0.05 mm/s) but at the same normal stress intervals as the main series. Using various techniques, we estimate the rate-and-state constitutive parameters. The peak stress after a certain amount of holding increases with a healing rate of b=0.0057±0.0005. From the increase in peak stress compared to the loading rate in slide-hold-slide tests we compute a direct effect a=-0.0076±0.0005 which leads to (a-b)=-0.0130±0.0006. Using a specific subset of the SHS tests, which have an equal ratio of hold time to reloading rate, we estimate (a-b)=-0.0087±0.0029. Both approaches show that the material is velocity weakening with a reduction in friction of 1.30 to 0.87 % per e-fold increase in loading rate. Additionally, the critical slip distance Dc is estimated to be in the range of 200 µm. With these parameters the theoretical critical stiffness kc is estimated and applied to the slip modes found in the main series. We find that the changes in slip mode are in good agreement with the estimated critical stiffness and thus confirm the findings from the SHS tests.
This data set includes the results of digital image correlation analysis applied to analogue modelling experiments (Table 1) on the effect of weakness during distributed crustal extension performed at the Helmholtz Laboratory for Tectonic Modelling (HelTec) of the GFZ German Research Centre for Geosciences in Potsdam. Ten generic analogue models made of a layer of Quartz sand (G12, Rosenau et al., 2018) including a weak silicone oil “seed” (PDMS G30M, Rudolf et al., 2016) to localize deformation have been extended on top of a basal foam block. A benchmark experiment (basal foam only) and a reference model (layer of sand without seed) are also reported. Detailed descriptions of the experiments can be found in Osagiede et al. (2021) to which this data set is supplement. The models have been monitored by means of digital image correlation (DIC) analysis (Adam et al., 2005). DIC analysis yields quantitative information about model surface deformation in 2D and 3D. The data presented here are visualized as finite strain and displacement maps as well as cumulative strain and displacement profiles.
This data set includes videos depicting the surface evolution (time laps photographs and Particle Image Velocimetry or PIV analsys) of 15 analogue models on rift tectonics, as well as 4D CT imagery (figures and videos) from four of these experiments. The experiments examined the influence of differently oriented mantle and crustal weaknesses on rift system development using a brittle-viscous set-up. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). Detailed descriptions of the experiments and monitoring techniques can be found in Zwaan et al. (2021).
| Organisation | Count |
|---|---|
| Wissenschaft | 24 |
| Type | Count |
|---|---|
| unbekannt | 24 |
| License | Count |
|---|---|
| Offen | 24 |
| Language | Count |
|---|---|
| Englisch | 24 |
| Resource type | Count |
|---|---|
| Keine | 24 |
| Topic | Count |
|---|---|
| Boden | 12 |
| Lebewesen und Lebensräume | 12 |
| Luft | 1 |
| Mensch und Umwelt | 24 |
| Wasser | 10 |
| Weitere | 24 |