The International Continental Scientific Drilling Program (ICDP) performed a dual-phase scientific drilling project called Collisional Orogeny in the Scandinavian Caledonides (COSC), to investigate mountain-building processes in the central Scandinavian Caledonides. The borehole COSC-1 was drilled through the Lower Seve Nappe, as the first of two 2.5 km deep drill holes close to Åre, central Sweden. As support for the COSC drilling project, an extensive seismic survey took place in 2014 in and around the newly drilled borehole COSC-1. The active seismic survey, among others, consisted of a high-resolution Zero-Offset Vertical Seismic Profiling (ZOVSP) experiment where seismic receivers were placed inside the borehole. For the seismic source signal a hydraulic hammer source (VIBSIST 3000) was used and activated over a period of 20 s as a sequence of impacts with increasing hit frequency. The wavefield was recorded in the borehole by 15 three-component receivers using a Sercel Slimwave geophone chain with an inter-tool spacing of 10 m. The ZOVSP was designed to result in a geophone spacing of 2 m over the whole borehole length. The source was about 30 meters away from the borehole. For component rotation, a check shot position was located about 1.9 km away from the borehole. This data set contains two data sets: (1) the decoded, pre-processed three-component shot gather, and (2) the final-processed shot gather of only the vertical component.
The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project focuses on mountain building processes in a major mid-Paleozoic orogen in western Scandinavia and its comparison with modern analogues. The transport and emplacement of subduction-related highgrade continent-ocean transition (COT) complexes onto the Baltoscandian platform and their influence on the underlying allochthons and basement is being studied in a section provided by two fully cored 2.5 km deep drill holes. These operational data sets concern the second drill site, COSC-2 (boreholes ICDP 5054-2-A and 5054-2-B), drilled from mid April to early August 2020. COSC-2 is located approximately 20 km eastsoutheast of COSC-1, close to the southern shore of Lake Liten between Järpen and Mörsil in Jämtland, Sweden. COSC-2 drilling started at a tectonostratigraphic level slightly below that at COSC-1’s total depth. It has sampled the Lower Allochthon, the main Caledonian décollement and the underlying basement of the Fennoscandian Shield, including its Neoproterozoic and possibly older sedimentary cover. COSC-2 A reached 2276 m driller's depth with nearly 100 % core recovery between 100 m and total depth. COSC-2 B, with a driller’s depth of 116 m, covers the uppermost part of the section that was not cored in COSC-2 A. The operational data sets include the drill core documentation from the drilling information system (mDIS), full round core scans, MSCL data sets, a preliminary core description and the geophysical downhole logging data that were acquired during and subsequent to the drilling operations. All downhole logs and core depth were subject to depth correction to a common depth master (cf. operational report for detailed information). The COSC-2 drill core is archived at the Core Repository for Scientific Drilling at the Federal Institute for Geosciences and Natural Resources (BGR), Wilhelmstr. 25–30, 13593 Berlin (Spandau), Germany.
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.
This is an updated version of Lorenz et al. (2015) and includes corrected locations of the boreholes and the core depths (for details see Lorenz et al., 2019,http://doi.org/10.2312/ICDP.5054.002), and newly provides access to the core scans in high resolution (uncompressed jpg format).The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project focuses on mountain building processes in a major mid-Paleozoic orogen in western Scandinavia and its comparison with modern analogues. The transport and emplacement of subduction-related highgrade continent-ocean transition (COT) complexes onto the Baltoscandian platform and their influence on the underlying allochthons and basement will be studied in a section provided by two fully cored 2.5 km deep drill holes. This operational report concerns the first drill hole, COSC-1 (ICDP 5054-1-A), drilled from early May to late August 2014.COSC-1 is located in the vicinity of the abandoned Fröå mine, close to the town of Åre in Jämtland, Sweden and was planned to sample a thick section of the Seve Nappe and to penetrate its basal thrust zone into the underlying lower grade metamorphosed allochthon. Despite substantial technical problems, the drill hole reached 2495.8 m driller's depth and nearly 100 % core recovery was achieved. Surprising was the homogeneity of the Seve Nappe rocks, the unexpected thickness of its basal thrust zone (> 500 m) and that the drill hole, therefore, did not penetrate the bottom of the thrust zone. However, lower grade metasedimentary rocks were encountered in the lowermost part of the drill hole together with tens of metres thick mylonites that are, unexpectedly, rich in large garnets.The drill core was documented on-site and XRF scanned off site. During various stages of the drilling, the borehole was documented by comprehensive downhole logging. The operational report provides an overview over the COSC-1 operations from drilling preparations to the sampling party and describes the available datasets and sample material.
The International Continental Scientific Drilling Program (ICDP) performed a dual-phase scientific drilling project to investigate mountain-building processes called Collisional Orogeny in the Scandinavian Caledonides (COSC). The borehole COSC-1 was drilled through the Lower Seve Nappe, as the first of two 2.5 km deep drill holes close to Åre, central Sweden. The recovered rocks comprise a 1650 m thick suite of high grade gneisses and amphibolites with clear Seve Nappe affinities, while the lower 850 m comprise rather homogenous mylonitic gneisses with interfingered K-rich phyllonite bands of cm to several m size and some intercalated amphibolites. The different lithologies all crosscut the core in a subhorizontal direction with foliation of gneisses and phyllonites in the same direction. Albite and garnet porphyroblasts with pressure shadows show syn-deformational growth and the same sub-horizontal alignment. The focus of this study was to detect chemical and mineralogical differences in mylonitic and host rocks and to relate these differences to either metasomatism and deformation or inherited source rock variance. Another goal of this work is to compare chemical core scanning instruments. For this purpose two different X-Ray Fluorescence (XRF) techniques, Laser Induced Breakdown Spectroscopy (LIBS) and hyperspectral imaging served to measure seven samples from the lower 850 m of the COSC-1 core. This data publication comprises the datasets gained in the course of this study. The metadata (OF WHAT?) will be presented in an additional file including XRF data from the Avaatech XRF core scanner in a txt.file as well as datasets of the other used devices in original file formats.
The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project focuses on mountain building processes in a major mid-Paleozoic orogen in western Scandinavia and its comparison with modern analogues. The transport and emplacement of subduction-related highgrade continent-ocean transition (COT) complexes onto the Baltoscandian platform and their influence on the underlying allochthons and basement will be studied in a section provided by two fully cored 2.5 km deep drill holes. This operational report concerns the first drill hole, COSC-1 (ICDP 5054-1-A), drilled from early May to late August 2014.COSC-1 is located in the vicinity of the abandoned Fröå mine, close to the town of Åre in Jämtland, Sweden and was planned to sample a thick section of the Seve Nappe and to penetrate its basal thrust zone into the underlying lower grade metamorphosed allochthon. Despite substantial technical problems, the drill hole reached 2495.8 m driller's depth and nearly 100 % core recovery was achieved. Surprising was the homogeneity of the Seve Nappe rocks, the unexpected thickness of its basal thrust zone (> 500 m) and that the drill hole, therefore, did not penetrate the bottom of the thrust zone. However, lower grade metasedimentary rocks were encountered in the lowermost part of the drill hole together with tens of metres thick mylonites that are, unexpectedly, rich in large garnets.The drill core was documented on-site and XRF scanned off site. During various stages of the drilling, the borehole was documented by comprehensive downhole logging. This operational report provides an overview over the COSC-1 operations from drilling preparations to the sampling party and describes the available datasets and sample material.
| Origin | Count |
|---|---|
| Wissenschaft | 6 |
| Type | Count |
|---|---|
| unbekannt | 6 |
| License | Count |
|---|---|
| offen | 6 |
| Language | Count |
|---|---|
| Englisch | 6 |
| Resource type | Count |
|---|---|
| Keine | 6 |
| Topic | Count |
|---|---|
| Boden | 5 |
| Lebewesen & Lebensräume | 5 |
| Mensch & Umwelt | 6 |
| Wasser | 1 |
| Weitere | 6 |