Seismic, Structural and Petrological Models of the Subcrustal Lithosphere in Southern Germany: A Quantitative Revaluation

Weiss, Thomas G.; Siegesmund, Siegfried; Bohlen, Thomas

doi:10.1007/978-3-0348-8670-3_4

Cited by 5 publications

(3 citation statements)

References 60 publications

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“…However, this model of anisotropy is not compatible with the recent studies of upper mantle anisotropy in the Fennoscandian shield [ Plomerová et al , 2001; Vecsey et al , 2007], which show that the fast velocity axis is usually inclined in anisotropic structures beneath the shield. In such a case all major types of olivine textures would manifest azimuthal dependence of Pn wave propagation [ Weiss et al , 1999a].…”

Section: Resultsmentioning

confidence: 99%

Evidence for preservation of crustal root beneath the Proterozoic Lapland‐Kola orogen (northern Fennoscandian shield) derived from P and S wave velocity models of POLAR and HUKKA wide‐angle reflection and refraction profiles and FIRE4 reflection transect

et al. 2009

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[1] We present an analysis of the crust and upper mantle in the northern Fennoscandian shield, based on new P and S wave 2-D velocity models of the POLAR and HUKKA wide-angle reflection and refraction profiles and results of a new seismic reflection experiment in Finland (Finnish Reflection Experiment). The profiles are almost collocated and crossed the Proterozoic Lapland-Kola orogen. A substantial difference of the depth of ''the wide-angle Moho'' (40-42 km) and ''the reflection Moho'' (47-50 km) was found. In order to explain this difference, we compared the velocity models to published values of Vp and Vp/Vs for the main types of lower crustal and mantle rocks. We found that the main reason for disagreement is that the wide-angle Moho and the reflection Moho correspond to different petrological boundaries. In the southwest and northeast portions of the profiles, the wide-angle Moho marks contact of either anorthositic or granulitic lower crust with a reflective layer in the upper mantle composed of peridotites and pyroxenites. The reflection Moho represents the bottom of this lower layer. In the center of the profile the wide-angle Moho marks the top of a large eclogitic body in the upper mantle, representing a well-preserved crustal root beneath the Lapland-Kola orogen formed because of the collision of three former Archaean crustal blocks (terranes or microcontinents). Lack of postorogenic tectonic collapse suggests another mechanism for stabilization of the lithosphere in the area. Upper mantle reflectors at depth of 65-75 km may mark the upper boundary of the cold and mechanically strong Archaean upper mantle wedge. Alternatively, these reflectors may represent a top of uplifted asthenosphere that can explain preservation of crustal root.Citation: Janik, T., E. Kozlovskaya, P. Heikkinen, J. Yliniemi, and H. Silvennoinen (2009), Evidence for preservation of crustal root beneath the Proterozoic Lapland-Kola orogen (northern Fennoscandian shield) derived from P and S wave velocity models of POLAR and HUKKA wide-angle reflection and refraction profiles and FIRE4 reflection transect,

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Section: Resultsmentioning

confidence: 99%

Evidence for preservation of crustal root beneath the Proterozoic Lapland‐Kola orogen (northern Fennoscandian shield) derived from P and S wave velocity models of POLAR and HUKKA wide‐angle reflection and refraction profiles and FIRE4 reflection transect

et al. 2009

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“…Typical values of rock samples are 5 to 8% order of magnitude for both velocity and shear wave splitting anisotropy (e.g. Christensen and Mooney, 1995;Gebrande, 1982;Kern, 1993;Weiss et al, 1999a). Seismic refraction measurements showed that the same size of azimuthal variation can be found in Pn-wave velocities near the Moho in both oceanic and continental settings (e.g.…”

Section: Type Of Derivative Lower Crustmentioning

confidence: 99%

Contrasts of seismic velocity, density and strength across the Moho

Rabbel¹,

Kaban

Tesauro

2013

Tectonophysics

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“…Under the assumption that the elastic constants of peridotite aggregate are known from petrophysical studies (see, e.g. Babuška et al 1993; Ben Ismaïl & Mainprice 1998; Weiss et al 1999), this requires two (hexagonal) or three (orthorhombic) spherical angles for unique determination of the orientation of the symmetry axes (Šílený & Plomerová 1996).…”

Section: Problem Formulation: Evaluation Of Seismic Anisotropy In Tmentioning

confidence: 99%

Joint inversion of multiple data types with the use of multiobjective optimization: problem formulation and application to the seismic anisotropy investigations

Kozlovskaya

Vecsey

Plomerová

et al. 2007

Geophysical Journal International

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S U M M A R YIn geophysical studies the problem of joint inversion of multiple experimental data sets obtained by different methods is conventionally considered as a scalar one. Namely, a solution is found by minimization of linear combination of functions describing the fit of the values predicted from the model to each set of data. In the present paper we demonstrate that this standard approach is not always justified and propose to consider a joint inversion problem as a multiobjective optimization problem (MOP), for which the misfit function is a vector. The method is based on analysis of two types of solutions to MOP considered in the space of misfit functions (objective space). The first one is a set of complete optimal solutions that minimize all the components of a vector misfit function simultaneously. The second one is a set of Pareto optimal solutions, or trade-off solutions, for which it is not possible to decrease any component of the vector misfit function without increasing at least one other. We investigate connection between the standard formulation of a joint inversion problem and the multiobjective formulation and demonstrate that the standard formulation is a particular case of scalarization of a multiobjective problem using a weighted sum of component misfit functions (objectives). We illustrate the multiobjective approach with a non-linear problem of the joint inversion of shear wave splitting parameters and longitudinal wave residuals. Using synthetic data and real data from three passive seismic experiments, we demonstrate that random noise in the data and inexact model parametrization destroy the complete optimal solution, which degenerates into a fairly large Pareto set. As a result, non-uniqueness of the problem of joint inversion increases. If the random noise in the data is the only source of uncertainty, the Pareto set expands around the true solution in the objective space. In this case the 'ideal point' method of scalarization of multiobjective problems can be used. If the uncertainty is due to inexact model parametrization, the Pareto set in the objective space deviates strongly from the true solution. In this case all scalarization methods fail to find the solution close to the true one and a change of model parametrization is necessary.

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Seismic, Structural and Petrological Models of the Subcrustal Lithosphere in Southern Germany: A Quantitative Revaluation

Cited by 5 publications

References 60 publications

Evidence for preservation of crustal root beneath the Proterozoic Lapland‐Kola orogen (northern Fennoscandian shield) derived from P and S wave velocity models of POLAR and HUKKA wide‐angle reflection and refraction profiles and FIRE4 reflection transect

Evidence for preservation of crustal root beneath the Proterozoic Lapland‐Kola orogen (northern Fennoscandian shield) derived from P and S wave velocity models of POLAR and HUKKA wide‐angle reflection and refraction profiles and FIRE4 reflection transect

Contrasts of seismic velocity, density and strength across the Moho

Joint inversion of multiple data types with the use of multiobjective optimization: problem formulation and application to the seismic anisotropy investigations

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