- Email: [email protected]
From crustal seismology to geodynamics – Contributions from the Rolf-Meissner-Symposium
Tectonophysics 692 (2016) 1–2
Contents lists available at ScienceDirect
Tectonophysics journal homepage: www.elsevier.com/locate/tecto
Preface
From crustal seismology to geodynamics – Contributions from the Rolf-Meissner-Symposium
1. Introduction This special issue presents a range of papers from a symposium held in Kiel on 5-6 June 2015 in honour of Rolf Meissner (1925-2014) focussing on the current state and future concepts of on- and offshore lithospheric research. In the late 1960s and 1970s Rolf Meissner demonstrated in pilot projects and conceptual papers, that deep seismic reflection measurements were feasible and capable of providing a wealth of geological information (e.g. Dohr & Meissner, 1975). Even for the Moon, he was co-author on studies describing the internal structure, evolution and origin from seismological data (e.g. Ewing et al. 1970, Meissner, 1977). He developed integrative concepts for the interpretation of these measurements and underlined the importance of petrology and rheology for understanding the seismic data and the underlying geodynamic processes (e.g. Meissner and Strehlau, 1982; Meissner, 1986; Meissner and Mooney, 1998). In this context, he coined such terms as seismic lamellae and crocodile tectonics (e.g. Meissner, 1989, Meissner et al. 2006), which spread throughout the community. His book from 1986 presented comprehensive knowledge on the continental crust and became internationally influential (Meissner, 1986). Many major national and international research programs on the structure and tectonic evolution of the continents were initiated or inspired and strongly influenced by Rolf Meissner’s work, for example, the German Continental Reflection Seismic Program (DEKORP: Meissner & Bortfeld 1990) and the Chinese-American-German project on deep profiling of Tibet and the Himalaya (INDEPTH/GEDEPTH), on which he kept working even after his official retirement (e.g. Meissner et al. 2004). Among his retirement activity was the release of his a book of planet Earth, where he summarized new discoveries and new concepts (Meissner, 2002). Rolf Meissner served as head of the Institute of Geophysics (now part of the Institute of Geosciences) at Kiel University from 1971 to 1995. By this stage of his career, he had developed pioneering concepts for investigating Earth’s crust, was well rooted in the lunar research program of NASA, and was well known and highly respected within industry circles. Through his leadership, the Kiel geophysical institute became internationally recognized as a leading science research facility. He succeeded in establishing geophysics in the educational program of the University of Kiel, covering an unprecedented breadth from nearsurface prospecting to planetary science. His success was founded not only on his exceptional scientific capabilities and his international standing but also on his passion and enthusiasm for science, which he
http://dx.doi.org/10.1016/j.tecto.2016.11.006 0040-1951/© 2016 Published by Elsevier B.V.
was able to share with his students, coworkers, and the scientific community at large. Besides by this volume, the legacy of Rolf Meissner was recently acknowledged by dedicating to him the thematic Tectonophysics volume on the Moho (Tectonophysics,Volume 609). Contributions The special issue is dedicated to the science legacy of Rolf Meissner and spanning the broad range from crustal seismology to the interpretation of tectonic and geodynamic processes by integration with additional geophysical methods. The 7 papers in the spirit of Rolf Meissner showcase the versatility of his interests: Snyder and Goleby (2016) discuss the important role of tectonic wedging in accommodating horizontal shortening strain, that is increasingly recognized to occur at all scales within continental convergence zones. This study is in the spirit by the work by Meissner and his students that published a series of papers noting that distinctive reflection patterns appearing on deep seismic reflection sections in Europe apparently correlated with the dominant, usually latest, tectonic deformation that had occurred in that crust (e.g. Meissner, 1989, Sadowiak et al., 1991). Wenning et al. (2016) discuss the seismic anisotropy in the mid to lower orogenic crust by using laboratory investigations of seismic anisotropy based on the first Collisional Orogeny in the Scandinavian Caledonides. The similarities in lithologies, shear zone thickness, and reflectivity pattern in the Central Scandinavian Caledonides compared to other orogens (e.g., the Himalaya) show the importance of such measurements as a proxy for in-situ strongly anisotropic shear zones in the middle crust, in line with earlier suggestion by Meissner (1989). The Caledonian deformation Front and its relation to the TeisseyreTornquist Zone (TTZ,) is the topic of the study by Mazur et al. (2016). By integrating seismic, gravity, magnetic and borehole data in NW Poland, the authors interpret that the Pomeranian Caledonides represent a thin-skinned fold-and-thrust belt involving Ordovician and Silurian sediments of the Caledonian foreland basin. Consequently, they propose a new model for the geodynamic setting that regards the TTZ as an intra-cratonic crustal discontinuity comparable to its NW prolongation, the Sorgenfrei-Tornquist Zone that runs across the Baltic Sea, Sweden and Denmark (e.g. Meissner et al. 1992, 1994). The East Greenland Caledonides are the focus of Schiffer et al. (2016). The authors discuss the implications of a complex upper mantle structure that was first detected by teleseismic data. Petrological and isostatic modelling of different scenarios for crust and upper mantle composition confirm the presence of a fossil Caledonian subduction
2
Preface
complex, including a slab of eclogitised mafic crust and an overlying wedge of serpentinised mantle. The geometry resembles a crocodile structure in the best tradition of Rolf Meissner. Meier et al. (2016) use seismic, geological and geochemical evidence to discuss the evolution of the Central European Lithosphere. In their analysis they demonstrate that a mosaic of tectonics blocks joint by Caledonian and Variscan orogenies dominate the upper crust, while the lower crust has been reworked by later tectonic processes. Directly relating their study to the work of Rolf Meissner, the authors conclude that their “ findings support the suggestion by Meissner et al. (1991) that the seismic signature of the lower parts of the lithosphere in central Europe, including the lower crust and the lithospheric mantle, are effectively younger that of the brittle upper crust. Further to the south, Diaz et al. (2016) discuss the Moho topography beneath the Iberian-Western Mediterranean region. Starting in the 1970s, the lithospheric structure has been extensively investigated using multichannel normal incidence seismic reflection and refraction/ wide-angle reflection profiling. High-resolution seismic surveys and the TopoIberia-IberArray experiment has triggered the investigations on crustal and lithospheric structure using natural seismicity, providing a homogeneous spatial resolution never achieved before, providing the opportunity to test the consistency of Moho depth estimations and providing a new crustal thickness map that varies from ~ 15 km in continental margins up to values exceeding 50 km beneath the Pyrenees or the Rif Cordillera, emphasizing the complex tectonic history of the area. Crustal modelling on a regional scale in the absence of such detailed seismic data is the focus of Holzrichter & Ebbing (2016). They demonstrate for the Arabian peninsula how novel satellite data, satellite gravity gradients, can be exploited to establish the crustal structure and thickness. The authors suggest that instead of normal gravity data, these gradients should be used as they provide a higher confidence in the resulting models. In combination with seismic models, this might result in improved crustal models on a regional and global scale useful for further analysis of tectonic and dynamic processes of the Earth. Acknowledgements The guest editors thank all the reviewers that provided invaluable suggestions to improve the manuscripts. We also appreciate the help of the Journal Editor, Rob Govers, and of the Tectonophysics editorial staff for their great support throughout the process. The symposium received support from the German Geophysical Society (DGG), the GEOMAR Helmholtz Center for Ocean Research, Allied Associates
Geophysical Ltd., GeoServe Applied Geophysics, Geosym GmbH, IGM Ingenieurgesellschaft für Geophysikalische Messtechnik mbH, K.U.M. Umwelt- und Meerestechnik Kiel GmbH, TEEC Geophysics GmbH, Wärtsilä ELAC Nautik GmbH, the Verein der Freunde und Förderer der Geophysik an der Universität Kiel, and, last but not least, from the University of Kiel through its excellence cluster Future Ocean, its Faculty of Mathematics and Natural Sciences and Institute of Geosciences. References Dohr, G.P., Meissner, R., 1975. Deep crustal reflections in Europe. Geophysics 40 (1), 25–39. Ewing, M., Latham, G., Press, F., Sutton, G., Dorman, J., Nakamura, Y., Meissner, R., Duennebier, F., Kovach, R., 1970. Seismology of the Moon and Implications on Internal Structure, Origin and Evolution. Highlights of Astronomy, 155-172, Springer.. Meissner, 1977. Lunar Viscosity Model. Phil. Trans. R. Soc. A 285, 1327. Meissner, R., 1989. Rupture, creep, lamellae and crocodiles: happenings in the continental crust. Terra Nova 1, 17–28. Meissner, R., Bortfeld, R.K., 1990. DEKORP-Atlas – Results of Deutsches Kontinentales Reflexionsseismisches Programm. Springer. Meissner, R., Mooney, W., 1998. Weakness of the lower continental crust: a condition for delamination, uplift, and escape. Tectonophysics 296, 47–60. Meissner, R., Strehlau, J., 1982. Limits of stresses in continental crusts and their relation to the depth-frequency distribution of shallow earthquakes. Tectonics 1, 73–89. Meissner, R., Wever, T., Sadowiak, P., 1991. Continental collisions and seismic signature. Geophys. J. Int. 105, 15–23. Meissner, R., Rabbel, W., Kern, H., 2006. Seismic lamination and anisotropy of the lower continental crust. Tectonophysics 416, 81–99. Meissner, R., Tilmann, F., Haines, S., 2004. About the lithospheric structure of central Tibet, based on seismic data from the INDEPTH III profile. Tectonophysics 380, 1–25. Meissner, R., Snyder, D., Balling, N., Staroste, E., 1992. The BABEL Project — First Status Report. Commission of the European Communities, Brussels. Meissner, R., Sadowiak, P., Thomas, S., 1994. East Avalonia, the third partner in the Caledonian collision: evidence from deep seismic reflection data. Geol. Rundsch. 83 (1994), 1136–1147. Meissner, 2002. The little book of planet Earth. Springer. Sadowiak, P., Wever, T., Meissner, R., 1991. Deep seismic reflectivity patterns in specific tectonic units of Western and Central Europe. Geophys. J. Int. 105, 45–54.
Jörg Ebbing* Wolfgang Rabbel Thomas Meier Sebastian Krastel Institute of Geosciences, Kiel University, 24118 Kiel, Germany *Corresponding author. E-mail address: [email protected].
Contents lists available at ScienceDirect
Tectonophysics journal homepage: www.elsevier.com/locate/tecto
Preface
From crustal seismology to geodynamics – Contributions from the Rolf-Meissner-Symposium
1. Introduction This special issue presents a range of papers from a symposium held in Kiel on 5-6 June 2015 in honour of Rolf Meissner (1925-2014) focussing on the current state and future concepts of on- and offshore lithospheric research. In the late 1960s and 1970s Rolf Meissner demonstrated in pilot projects and conceptual papers, that deep seismic reflection measurements were feasible and capable of providing a wealth of geological information (e.g. Dohr & Meissner, 1975). Even for the Moon, he was co-author on studies describing the internal structure, evolution and origin from seismological data (e.g. Ewing et al. 1970, Meissner, 1977). He developed integrative concepts for the interpretation of these measurements and underlined the importance of petrology and rheology for understanding the seismic data and the underlying geodynamic processes (e.g. Meissner and Strehlau, 1982; Meissner, 1986; Meissner and Mooney, 1998). In this context, he coined such terms as seismic lamellae and crocodile tectonics (e.g. Meissner, 1989, Meissner et al. 2006), which spread throughout the community. His book from 1986 presented comprehensive knowledge on the continental crust and became internationally influential (Meissner, 1986). Many major national and international research programs on the structure and tectonic evolution of the continents were initiated or inspired and strongly influenced by Rolf Meissner’s work, for example, the German Continental Reflection Seismic Program (DEKORP: Meissner & Bortfeld 1990) and the Chinese-American-German project on deep profiling of Tibet and the Himalaya (INDEPTH/GEDEPTH), on which he kept working even after his official retirement (e.g. Meissner et al. 2004). Among his retirement activity was the release of his a book of planet Earth, where he summarized new discoveries and new concepts (Meissner, 2002). Rolf Meissner served as head of the Institute of Geophysics (now part of the Institute of Geosciences) at Kiel University from 1971 to 1995. By this stage of his career, he had developed pioneering concepts for investigating Earth’s crust, was well rooted in the lunar research program of NASA, and was well known and highly respected within industry circles. Through his leadership, the Kiel geophysical institute became internationally recognized as a leading science research facility. He succeeded in establishing geophysics in the educational program of the University of Kiel, covering an unprecedented breadth from nearsurface prospecting to planetary science. His success was founded not only on his exceptional scientific capabilities and his international standing but also on his passion and enthusiasm for science, which he
http://dx.doi.org/10.1016/j.tecto.2016.11.006 0040-1951/© 2016 Published by Elsevier B.V.
was able to share with his students, coworkers, and the scientific community at large. Besides by this volume, the legacy of Rolf Meissner was recently acknowledged by dedicating to him the thematic Tectonophysics volume on the Moho (Tectonophysics,Volume 609). Contributions The special issue is dedicated to the science legacy of Rolf Meissner and spanning the broad range from crustal seismology to the interpretation of tectonic and geodynamic processes by integration with additional geophysical methods. The 7 papers in the spirit of Rolf Meissner showcase the versatility of his interests: Snyder and Goleby (2016) discuss the important role of tectonic wedging in accommodating horizontal shortening strain, that is increasingly recognized to occur at all scales within continental convergence zones. This study is in the spirit by the work by Meissner and his students that published a series of papers noting that distinctive reflection patterns appearing on deep seismic reflection sections in Europe apparently correlated with the dominant, usually latest, tectonic deformation that had occurred in that crust (e.g. Meissner, 1989, Sadowiak et al., 1991). Wenning et al. (2016) discuss the seismic anisotropy in the mid to lower orogenic crust by using laboratory investigations of seismic anisotropy based on the first Collisional Orogeny in the Scandinavian Caledonides. The similarities in lithologies, shear zone thickness, and reflectivity pattern in the Central Scandinavian Caledonides compared to other orogens (e.g., the Himalaya) show the importance of such measurements as a proxy for in-situ strongly anisotropic shear zones in the middle crust, in line with earlier suggestion by Meissner (1989). The Caledonian deformation Front and its relation to the TeisseyreTornquist Zone (TTZ,) is the topic of the study by Mazur et al. (2016). By integrating seismic, gravity, magnetic and borehole data in NW Poland, the authors interpret that the Pomeranian Caledonides represent a thin-skinned fold-and-thrust belt involving Ordovician and Silurian sediments of the Caledonian foreland basin. Consequently, they propose a new model for the geodynamic setting that regards the TTZ as an intra-cratonic crustal discontinuity comparable to its NW prolongation, the Sorgenfrei-Tornquist Zone that runs across the Baltic Sea, Sweden and Denmark (e.g. Meissner et al. 1992, 1994). The East Greenland Caledonides are the focus of Schiffer et al. (2016). The authors discuss the implications of a complex upper mantle structure that was first detected by teleseismic data. Petrological and isostatic modelling of different scenarios for crust and upper mantle composition confirm the presence of a fossil Caledonian subduction
2
Preface
complex, including a slab of eclogitised mafic crust and an overlying wedge of serpentinised mantle. The geometry resembles a crocodile structure in the best tradition of Rolf Meissner. Meier et al. (2016) use seismic, geological and geochemical evidence to discuss the evolution of the Central European Lithosphere. In their analysis they demonstrate that a mosaic of tectonics blocks joint by Caledonian and Variscan orogenies dominate the upper crust, while the lower crust has been reworked by later tectonic processes. Directly relating their study to the work of Rolf Meissner, the authors conclude that their “ findings support the suggestion by Meissner et al. (1991) that the seismic signature of the lower parts of the lithosphere in central Europe, including the lower crust and the lithospheric mantle, are effectively younger that of the brittle upper crust. Further to the south, Diaz et al. (2016) discuss the Moho topography beneath the Iberian-Western Mediterranean region. Starting in the 1970s, the lithospheric structure has been extensively investigated using multichannel normal incidence seismic reflection and refraction/ wide-angle reflection profiling. High-resolution seismic surveys and the TopoIberia-IberArray experiment has triggered the investigations on crustal and lithospheric structure using natural seismicity, providing a homogeneous spatial resolution never achieved before, providing the opportunity to test the consistency of Moho depth estimations and providing a new crustal thickness map that varies from ~ 15 km in continental margins up to values exceeding 50 km beneath the Pyrenees or the Rif Cordillera, emphasizing the complex tectonic history of the area. Crustal modelling on a regional scale in the absence of such detailed seismic data is the focus of Holzrichter & Ebbing (2016). They demonstrate for the Arabian peninsula how novel satellite data, satellite gravity gradients, can be exploited to establish the crustal structure and thickness. The authors suggest that instead of normal gravity data, these gradients should be used as they provide a higher confidence in the resulting models. In combination with seismic models, this might result in improved crustal models on a regional and global scale useful for further analysis of tectonic and dynamic processes of the Earth. Acknowledgements The guest editors thank all the reviewers that provided invaluable suggestions to improve the manuscripts. We also appreciate the help of the Journal Editor, Rob Govers, and of the Tectonophysics editorial staff for their great support throughout the process. The symposium received support from the German Geophysical Society (DGG), the GEOMAR Helmholtz Center for Ocean Research, Allied Associates
Geophysical Ltd., GeoServe Applied Geophysics, Geosym GmbH, IGM Ingenieurgesellschaft für Geophysikalische Messtechnik mbH, K.U.M. Umwelt- und Meerestechnik Kiel GmbH, TEEC Geophysics GmbH, Wärtsilä ELAC Nautik GmbH, the Verein der Freunde und Förderer der Geophysik an der Universität Kiel, and, last but not least, from the University of Kiel through its excellence cluster Future Ocean, its Faculty of Mathematics and Natural Sciences and Institute of Geosciences. References Dohr, G.P., Meissner, R., 1975. Deep crustal reflections in Europe. Geophysics 40 (1), 25–39. Ewing, M., Latham, G., Press, F., Sutton, G., Dorman, J., Nakamura, Y., Meissner, R., Duennebier, F., Kovach, R., 1970. Seismology of the Moon and Implications on Internal Structure, Origin and Evolution. Highlights of Astronomy, 155-172, Springer.. Meissner, 1977. Lunar Viscosity Model. Phil. Trans. R. Soc. A 285, 1327. Meissner, R., 1989. Rupture, creep, lamellae and crocodiles: happenings in the continental crust. Terra Nova 1, 17–28. Meissner, R., Bortfeld, R.K., 1990. DEKORP-Atlas – Results of Deutsches Kontinentales Reflexionsseismisches Programm. Springer. Meissner, R., Mooney, W., 1998. Weakness of the lower continental crust: a condition for delamination, uplift, and escape. Tectonophysics 296, 47–60. Meissner, R., Strehlau, J., 1982. Limits of stresses in continental crusts and their relation to the depth-frequency distribution of shallow earthquakes. Tectonics 1, 73–89. Meissner, R., Wever, T., Sadowiak, P., 1991. Continental collisions and seismic signature. Geophys. J. Int. 105, 15–23. Meissner, R., Rabbel, W., Kern, H., 2006. Seismic lamination and anisotropy of the lower continental crust. Tectonophysics 416, 81–99. Meissner, R., Tilmann, F., Haines, S., 2004. About the lithospheric structure of central Tibet, based on seismic data from the INDEPTH III profile. Tectonophysics 380, 1–25. Meissner, R., Snyder, D., Balling, N., Staroste, E., 1992. The BABEL Project — First Status Report. Commission of the European Communities, Brussels. Meissner, R., Sadowiak, P., Thomas, S., 1994. East Avalonia, the third partner in the Caledonian collision: evidence from deep seismic reflection data. Geol. Rundsch. 83 (1994), 1136–1147. Meissner, 2002. The little book of planet Earth. Springer. Sadowiak, P., Wever, T., Meissner, R., 1991. Deep seismic reflectivity patterns in specific tectonic units of Western and Central Europe. Geophys. J. Int. 105, 45–54.
Jörg Ebbing* Wolfgang Rabbel Thomas Meier Sebastian Krastel Institute of Geosciences, Kiel University, 24118 Kiel, Germany *Corresponding author. E-mail address: [email protected].