The Collisional Orogeny in the Scandinavian Caledonides (COSC) drilling project focuses on understanding orogenic processes in western Scandinavia (Lorenz et al., 2015). The project presents an opportunity to study how heat transport affects brittle and ductile deformation in the lithosphere. Here, we present results of measurements with an optical scanning instrument (Thermal Conductivity Scanner; TCS) on about 100 core samples retrieved from the borehole COSC-1. Details about the measurement procedures are given in the following sections.
For a list of core sample IDs that are assigned with International Generic Sample Numbers (IGSN, see Conze et al., 2017), please see the associated data description file. The sample IDs give the identifier of the borehole (5054_1_a) and then core# and section# (e.g., 5054_1_A_7_1_WR_4-24, where core# is 7 and section# is 1). Further information (e.g., elevation, depth, sample photos, etc.) about each sample can be found on the GFZ Data Services repository. Individual sample pages can be accessed directly using the IGSN, for example: https://igsn.org/ICDP5054EX71601 (or via the links in the Related Works section of this DOI landing page).
The TCS measurements were made at the Fraunhofer Institute, Bochum, formerly known as the International Geothermal Centre, Bochum, on a Lippmann Geophysical Instruments TCSCAN, hardware version 2 (https://www.l-gm.de/en/en_tcs.html). The procedure used for the measurements is described in the user manual, which can be found at https://www.tcscan.de.
Core samples have been taken for complementary laboratory seismic measurements and mineralogical analyses on whole rock core from the COSC-1 borehole, Sweden (UTM 63.3124, 13.5259). These samples were used to provide and characterize the seismic properties (i.e., seismic velocities and anisotropy) of the drilled rocks from the highly metamorphosed and deformed Seve Nappe Complex, an orogenic thrust zone in the Scandinavian Caledonides, in central Sweden.
The laboratory seismic and mineralogical analysis in general comprises three distinct measurements (i.e., data sets), which will be described in detail in the following subsections: (1) P- and S-wave laboratory seismic measurements on three perpendicular core plugs, under different confining (hydrostatic) pressure conditions (10 + 6 samples), (2) Bulk mineralogy of core plugs using X-ray powder diffraction (XRD) and mineral chemical composition measurements using an electron probe micro-analyzer (EPMA, here microprobe), on 10 thin sections and (3) Microstructural investigations based on electron-backscatter diffraction analyses on 5 thin sections.
The laboratory seismic measurements were initially conducted on 6 samples by Wenning et al. (2016) and extended by another 10 samples by Kästner et al. (2020). Despite these authors were using the same sensor setup, the provided data files may differ due to individual acquisition parameters. Where different acquisition, processing, or calibration parameters are used this is indicated in the text using the abbreviations FK and QW referring to each examiner and their related sample measurements. International Geo Sample Numbers (IGSN) are provided for each core sample in the complete sample data table.