Estimation of crustal viscosities and shear stresses from an extrapolation of experimental steady state flow data

Strehlau, Jurgen; Meißner, R.

doi:10.1029/gd016p0069

Cited by 57 publications

(26 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3C and D). These calculations are in good agreement with those expected in ultramafic rocks at the given temperatures and depths (Strehlau and Meissner, 1987;Goes and Van der Lee, 2002). The observed S-wave anomalies in Fig.…”

Section: Low Angle Subductionsupporting

confidence: 89%

“…2). This suggests that a defect free "wet" dunite rheology would still produce a too high differential stress field in the lithospheric mantle according to Bayerlee's law, which is contradictory to the observed S-wave velocity anomalies (Strehlau and Meissner, 1987;Durinck et al, 2005). Consequently, the water generating the "wetness" of the lithospheric mantle must be located along grain boundaries and two-dimensional defect structures or in hydrous minerals to explain the lithospheric mantle tomography, as seen in this study (Sommer et al, 2008).…”

Section: Implications and Conclusionmentioning

confidence: 54%

“…Fig. 5A shows the S-wave velocities are not anomalous at MOHO depth, suggesting a dry granitic-gneissic continental crust (Strehlau and Meissner, 1987). However, at a depth of 70 km, S-wave velocities are about 350 m/s less than an average of 4.5 km/s in surrounding lithospheric mantle (Figs.…”

Section: Low Angle Subductionmentioning

confidence: 94%

“…The addition of water is known to significantly decrease the viscosity of olivine (Strehlau and Meissner, 1987;Hirth and Kohlstedt, 1996;Dixon et al, 2004). Humphreys et al (2003) have further suggested that hydration of the overriding North American lithosphere may have also promoted magmatic activity after slab rollback by depressing the solidus in the lithosphere.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Hydrating laterally extensive regions of continental lithosphere by flat subduction: A pilot study from the North American Cordillera

Sommer

Gauert

2011

Journal of Geodynamics

View full text Add to dashboard Cite

Section: Low Angle Subductionsupporting

confidence: 89%

Section: Implications and Conclusionmentioning

confidence: 54%

Section: Low Angle Subductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydrating laterally extensive regions of continental lithosphere by flat subduction: A pilot study from the North American Cordillera

Sommer

Gauert

2011

Journal of Geodynamics

View full text Add to dashboard Cite

“…Creep parameters for dry Columbia diabase (Mackwell et al 1998) are the other end member representing a very stiff lower crust. Moreover, the flow law data for a another dry diabase (Strehlau and Meissner 1987) is used as an intermediate rheology which is still considerably stiffer than the reference rheology for a given temperature and strain rate. Background heat flow and radiogenic heat production are adjusted in order to vary the initial surface heat flow from 60 mW/m 2 to 80 mW/m 2 leading to Moho temperatures from 600°C to 700°C and to a maximum depth of the upper crustal faults between 12 km and 18 km.…”

Section: Lower Crustal Rheology and Thermal Conditionsmentioning

confidence: 99%

Evolution and structure of the Upper Rhine Graben: insights from three-dimensional thermomechanical modelling

Schwarz

Henk

2004

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

The evolution and geometry of the Tertiary Upper Rhine Graben were controlled by a continually changing stress field and the reactivation of pre-existing crustal discontinuities. A period of WNW-ESE extension in the late Eocene and Oligocene was followed by lateral translation from the early Miocene onwards. This study utilizes 3D finite element techniques to simulate extension and lateral translation on a lithospheric scale. Brittle and creep behaviour of lithospheric rocks are represented by elastoplasticity and thermally activated power-law viscoplasticity, respectively. Contact elements allocated with cohesion and frictional coefficients are used to describe pre-existing zones of weakness in the elastic-brittle field. Our results suggest that (1) extension is accommodated along listric border faults to midcrustal depth of 15-16 km. Beneath, pure shear stretching occurs without a need for localized shear zones in lower crust and upper mantle. (2) Ductile flow at midcrustal depth across the graben accounts for the pronounced halfgraben morphology. Thereby, the shape of the border faults, their frictional coefficients, and sedimentary loads have profound effects on the rate of ductile flow across the graben. (3) Horizontal extension of 8-8.5 km and sinistral displacement across the rift of 3-4 km are needed to accommodate the observed sediment thickness.

show abstract

Cyclic ductile and brittle deformation related to coseismic thrust fault propagation: Structural record at the base of a basement nappe (Preveli, Crete)

2013

View full text Add to dashboard Cite

[1] The structural record at the base of a basement nappe (Preveli nappe, Crete, Greece) thrust upon sedimentary rocks is investigated, aimed on understanding mechanisms which result in decoupling of the thrust sheet from its original substratum. We identify several superimposed deformation stages, each with characteristic structural style and indications of episodic deformation at initially high differential stress. The final stage involves formation of a matrix supported breccia transected by pseudotachylytes, comprising the lowermost 30 m of the nappe. Brecciation and pseudotachylyte formation occurred in a single event, and structures were not modified afterward. Complete induration of breccia and composition of phengite crystallized during devitrification of pseudotachylytes place the sequence of events into the middle crust. We propose a model relating episodic deformation and cyclic stress history to propagation of a thrust fault in a limited number of seismic events. Terminal brecciation and frictional fusion record passage of the fault front beneath the site of observation and decoupling of the thrust sheet. Absence of discernible further deformation is consistent with negligible basal friction during transport as a nappe. Brecciation and pseudotachylyte formation mark the switch from a history of repeated coseismic loading and postseismic stress relaxation in the plastosphere, driven by seismic events on the approaching thrust fault, to passive transport with deformation localized in a weak thrust plane. For a sequence of superimposed ductile to brittle structures, our model provides an alternative to progressive cooling and exhumation concomitant with deformation over millions of years.Citation: Nu¨chter, J.-A., S. Wassmann, and B. Sto¨ckhert (2013), Cyclic ductile and brittle deformation related to coseismic thrust fault propagation: Structural record at the base of a basement nappe (Preveli, Crete), Tectonics, 32,

show abstract

Estimation of crustal viscosities and shear stresses from an extrapolation of experimental steady state flow data

Cited by 57 publications

References 73 publications

Hydrating laterally extensive regions of continental lithosphere by flat subduction: A pilot study from the North American Cordillera

Hydrating laterally extensive regions of continental lithosphere by flat subduction: A pilot study from the North American Cordillera

Evolution and structure of the Upper Rhine Graben: insights from three-dimensional thermomechanical modelling

Cyclic ductile and brittle deformation related to coseismic thrust fault propagation: Structural record at the base of a basement nappe (Preveli, Crete)

Contact Info

Product

Resources

About