[COSC] COSC - Collisional Orogeny in the Scandinavian Caledonides

Climate & Ecosystems
Natural Hazards

Year of Application: 2017

Expedition ID: 5054

Current Status: drilled

Master Data

Prof. Dr. Christophe Pascal (PI)

Ronald Conze (OSG)
Dr. Ulrich Harms (OSG)
Jochem Kück (OSG)
Johannes Hierold (Scientific Participant)
Prof. Dr. Jörg Renner (Scientific Participant)
Prof. Dr. Reinhard O. Greiling (Scientific Participant)
Dr. Felix Krauß (Scientific Participant)
Dr. Jens Carsten Grimmer (Scientific Participant)
Dr. Rüdiger Giese (Scientific Participant)
Dr. Oliver Lehnert (Scientific Participant)
Prof. Dr. Stefan Buske (Scientific Participant)
Friederike Körting (Scientific Participant)
Prof. Dr. Christian Berndt (Scientific Participant)
Felix Kästner (Scientific Participant)
Helge Simon (Scientific Participant)
Dr. Simona Pierdominici (Scientific Participant)
Richard Löwe (Scientific Participant)
Dr. Johannes Glodny (Scientific Participant)
Dr. Judith Elger (Scientific Participant)
Prof. Dr. Jörg Ebbing (Workshop Participant)
Prof. Dr. Christoph Clauser (Workshop Participant)

Geologisches Alter: Mid-Paleozoic

Latitude: 63°24'5''N


Regionen & Städte:

Fennoscandian Shield

Longitude: 13°12'10''E



Mountain Building

Paleozoic mountain building and modern analogues on a regional to global scale Understand the main décollement in the foreland of one of the Earth’s largest orogens and the character of the deformation in the basement below.

Foreland-hinterland connections

Research foreland-hinterland connections during continental collision and passive margin development after continental break-up.

natural hazards of modern orogenic environments

Utilise the new knowledge to better understand the nature and occurrence of natural hazards in modern orogenic environments. Early Paleozoic evolution of Baltica and the Ordovician-Silurian boundary Investigate the development of the Early Paleozoic basin.

extensive glaciations on Gondwana and mass extinction at the Ordovician-Silurian boundary

nvestigate the environmental conditions during this period of Gondwana-Baltica-Laurentia juxtaposition with major episodes of change such as extensive glaciations on Gondwana and mass extinction at the Ordovician-Silurian boundary. Holocene climate evolution Reconstruct the ground surface temperature history to gather new knowledge about the Weichselian glaciation and climate evolution in northern Europe during the Holocene. Hydrogeological and geothermic characteristics of (old) mountain belts Understand the origin and genesis of fluids and gases and their impact on seismicity and rheology.

transfer in the basement, across thrust zones and in the allochthons

Explore the means of heat transfer in the basement, across thrust zones and in the allochthons. The composition of deep microbial communities and energy sources Assess the change of populations and activities with depth and the concomitant transition between the energy sources organic carbon from surface and the geogases carbon dioxide and hydrogen.

microbial communities

Investigate the transition with depth from microbial communities dominated by bacteria to those primarily composed by archaea in crystalline bedrock fracture systems.

traces of Paleozoic to Quaternary microbial activity

Investigate the traces of Paleozoic to Quaternary microbial activity in secondary minerals.

Drilling Data

Drilling Depth: 2276.0
Core Yield: 100.0
Core Length: 2276.0
Amount of Drill Holes: 2
Amount of Drill Locations:

Core Length-Drill Depth-Ratio: 100.0
Core Yield-Core Length-Ratio: 100.0


The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project is investigating mountain building processes at mid to lower crustal levels in a deeply eroded Paleozoic collisional orogen of Himalayan dimensions. Two fully cored COSC boreholes will provide a unique circa 5 km deep composite section from a subduction related allochthon through the underlying continental margin, mostly cover-derived nappes, and the basal décollement into Precambrian crystalline basement. Utilising the Caledonides as an analogue to comparable tectonic settings, such as the Himalaya, will advance our understanding of orogenic systems and how they affect the stability of the living environment. COSC-1, drilled in 2014, investigated the emplacement of the high-grade (UHP) metamorphic allochthons. COSC-2 (this proposal) will define the character and age of deformation of the underlying greenschist facies thrust-sheets, the main Caledonian décollement and the Precambrian basement. The upper part of the borehole will sample a Cambro-Silurian succession, including both distal shelf sedimentary formations typical of the Baltoscandian platform and also foreland basin turbidites of both mid Ordovician and Early Silurian age, separated by significant environmental changes at the Ordovician-Silurian boundary. After drilling through the main décollement, COSC-2 will penetrate 1-1.5 km into the basement of the Fennoscandian Shield, where prominent seismic reflections indicate the presence of significant crustal shortening of Caledonian or Sveconorwegian age. Study of this internal basement deformation is particularly important for understanding the passage from thin-skinned tectonics in the foreland of the orogen to thick-skinned tectonics in the hinterland, where the underriding Baltica plate experienced deformation and (U)HP metamorphism. ICDP drilling will result in a fully cored borehole that will be further characterised by downhole logging, as well as complemented by VSP and electromagnetic surveys in separate projects. COSC-2 research will span several geoscientific disciplines – geology, geophysics, geochronology, hydrogeology, geothermics and microbiology – performed by various constellations of the COSC science team who will seek funds from national and international funding agencies. Tasks such as Modern analogues – incipient and active orogens, Foreland – hinterland – off-shore connection and others will coordinate the multidisciplinary expertise of the international science team to effectively address the scientific targets. The COSC-2 scientific targets address four out of the five themes identified as the way forward in the ICDP Science Plan 2014: Active Faults and Earthquakes, Global Cycles and Environmental Change, Heat and Mass Transfer and The Ubiquitous Hidden Biosphere.

Related Publications

Westmeijer, G., Escudero, C., Bergin, C., Turner, S., Ståhle, M., Mehrshad, M., Leroy, P., Buck, M., López-Hernández, P., Kallmeyer, J., Amils, R., Bertilsson, S., Dopson, M. (2023). "Continental scientific drilling and microbiology: (extremely) low biomass in crystalline bedrock of central Sweden" Biogeosciences Discuss. p1-22

Kästner, Felix, Klaeschen, Dirk, Berndt, Christian, Pierdominici, Simona, Hedin, Peter (2022). "Anisotropic velocity models for (3-D) seismic imaging of the Lower Seve Nappe in Jämtland, Sweden" Geophysical Journal International 228 p66-77

Christian Kulüke (2022). "Aspekte der Verarbeitung von Komponentenmessungen in der Magnetik" Dissertation p177

Lorenz, Henning, Rosberg, Jan-Erik, Juhlin, Christopher, Klonowska, Iwona, Lescoutre, Rodolphe, Westmeijer, George, Almqvist, Bjarne SG, Anderson, Mark, Bertilsson, Stefan, Dopson, Mark (2022). "COSC-2–drilling the basal décollement and underlying margin of palaeocontinent Baltica in the Paleozoic Caledonide Orogen of Scandinavia" Scientific Drilling 30 p43-57

Felix Kästner (2021). "Core-log-seismic data integration at the COSC-1 borehole in the Central Scandinavian Caledonides" Dissertation p146

Elger, Judith, Berndt, Christian, Kästner, Felix, Pierdominici, Simona, Kück, Jochem, Almqvist, Bjarne SG, Juhlin, Christopher, Lorenz, Henning (2021). "Core‐log‐seismic integration in metamorphic rocks and its implication for the regional geology: A case study for the ICDP drilling project COSC‐1, Sweden" Geochemistry, Geophysics, Geosystems 22 pe2020GC009376

Kästner, Felix, Pierdominici, Simona, Zappone, Alba, Morales, Luiz FG, Schleicher, Anja M, Wilke, Franziska DH, Berndt, Christian (2021). "Cross‐scale seismic anisotropy analysis in metamorphic rocks from the COSC‐1 borehole in the Scandinavian Caledonides" Journal of Geophysical Research: Solid Earth pe2020JB021154

Kästner, Felix, Pierdominici, Simona, Elger, Judith, Zappone, Alba, Kück, Jochem, Berndt, Christian (2020). "Correlation of core and downhole seismic velocities in high-pressure metamorphic rocks: a case study for the COSC-1 borehole, Sweden" Solid Earth 11 p607-626

Löwe, Richard H (2020). "Steady-state vs. transient heat-transfer in the COSC-1 drill hole, Central Sweden" Dissertation p324

Simon, Helge, Buske, Stefan, Hedin, P, Juhlin, C, Krauß, Felix, Giese, R (2019). "Anisotropic Kirchhoff pre-stack depth migration at the COSC-1 borehole, central Sweden" Geophysical Journal International 2019 p66-79

Kästner, F., Pierdominici, S., Elger, J., Zappone, A., Kück, J., Berndt, C. (2019). "Correlation of core and downhole seismic velocities in high-pressure metamorphic rocks: A case study for the COSC-1 borehole, Sweden" Solid Earth discussion p1-31

Krauß, Felix (2018). "Combination of Borehole Seismic and Downhole Logging to Investigate the Vicinity of the COSC-1 Borehole in Western Scandinavia" Dissertation p183

Simon, H, Buske, S, Krau, F, Giese, R, Hedin, P, Juhlin, C (2017). "The derivation of an anisotropic velocity model from a combined surface and borehole seismic survey in crystalline environment at the COSC-1 borehole, central Sweden" Geophysical Journal International 210 p1332-1346

Conze, Ronald, Lorenz, Henning, Ulbricht, Damian, Elger, Kirsten, Gorgas, Thomas (2017). "Utilizing the International Geo Sample Number Concept in Continental Scientific Drilling During ICDP Expedition COSC-1" Data Science Journal

Hedin, Peter, Almqvist, Bjarne, Berthet, Théo, Juhlin, Christopher, Buske, Stefan, Simon, Helge, Giese, Rüdiger, Krauß, Felix, Rosberg, Jan-Erik, Alm, Per-Gunnar (2016). "3D reflection seismic imaging at the 2.5km deep COSC-1 scientific borehole, central Scandinavian Caledonides" Tectonophysics 689 p40-55

Lorenz, Henning, Rosberg, J-E, Juhlin, Christopher, Bjelm, Leif, Almqvist, Bjarne Sven Gustav, Berthet, Théo, Conze, Ronald, Gee, David Godfrey, Klonowska, Iwona, Pascal, Christophe (2015). "COSC-1–drilling of a subduction-related allochthon in the Palaeozoic Caledonide orogen of Scandinavia" Scientific Drilling 19 p1-11

Gee, David G, Juhlin, Christopher, Pascal, Christophe, Robinson, Peter (2010). "Collisional orogeny in the Scandinavian Caledonides (COSC)" Gff 132 p29-44