This dataset provides friction data from ring-shear tests (RST) on feldspar sand and quartz sand, which are used to simulate brittle behaviour in crust- and lithosphere-scale analogue experiments at the Tectonic Laboratory (TecLab), Utrecht University (NL) (Willingshofer et al., 2005; Willingshofer & Sokoutis, 2009; Athmer et al., 2010; Luth et al., 2010; Fernández-Lozano et al., 2011; Leever et al., 2011; Sokoutis & Willingshofer, 2011; Fernández-Lozano et al., 2012; Luth et al., 2013; Munteanu et al., 2013; Willingshofer et al., 2013; Munteanu et al., 2014; Calignano et al., 2015a, b; Ortner et al., 2015; Gabrielsen et al., 2016; Calignano et al., 2017; van Gelder et al., 2017; Wang et al., 2017; Beniest et al., 2018 ). The materials have been characterized by means of internal friction coefficients µ and cohesions C as a remote service by the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam.
According to our analysis both materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the feldspar sand are µP = 0.68, µD = 0.55, and µR = 0.61, respectively. Friction coefficients of the quartz sand are µP = 0.63, µD = 0.48, and µR = 0.52, respectively. Cohesions of the feldspar sand and the quartz sand are in the order of few tens of Pa. A minor rate-weakening of 1% per ten-fold rate change is evident for the feldspar sand, whereas the quartz sand shows a significant rate weakening of ~5%.
Further information about materical characteristics, measurement procedures, sample preparation, the RST (Ring-shear test) and VST (Velocity stepping test) procedure, as well as the analysed method is proviced in the data description file. The list of files explains the file and folder structure of the data set.