Seismicity of the northern Upper Rhine Graben — Constraints on the present-day stress field from focal mechanisms

Homuth, Benjamin; Rümpker, Georg; Deckert, Hagen; Kracht, Matthias

doi:10.1016/j.tecto.2014.05.037

Cited by 17 publications

(18 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The predictions of these models are consistent with observations suggesting transtension followed by normal extension in many active or fossil rift systems that formed parallel to ancient collisional belts, such as the East African rift (Bosworth and Strecker, 1997), the Rhine graben (Schumacher, 2002;Homuth et al, 2014), and the rifts leading to the break-up of eastern Gondwana (Powell et al, 1988;Jacob and Dyment, 2014) and the opening of the North Atlantic (Geoffroy et al, 1994). These models also explain the common reactivation of large-scale wrench faults during successive collisional and extensional episodes.…”

Section: Accepted Manuscriptsupporting

confidence: 82%

Heterogeneity and anisotropy in the lithospheric mantle

2015

View full text Add to dashboard Cite

International audienceThe lithospheric mantle is intrinsically heterogeneous and anisotropic. These two properties govern the repartition of deformation, controlling intraplate strain localization and development of new plate boundaries. Geophysical and geological observations provide clues on the types, ranges, and characteristic length scales of heterogeneity and anisotropy in the lithospheric mantle. Seismic tomography points to variations in geothermal gradient and hence in rheological behavior at scales of hundreds of km. Seismic anisotropy data substantiate anisotropic physical properties consistent at scales of tens to hundreds of km. Receiver functions imply lateral and vertical heterogeneity at scales < 10 km, which might record gradients in composition or anisotropy. Observations on naturally deformed peridotites establish that compositional heterogeneity and Crystal Preferred Orientations (CPOs) are ubiquitous from the mm to the km scales. These data allow discussing the processes that produce/destroy heterogeneity and anisotropy and constraining the time scales over which they are active. This analysis highlights: (i) the role of deformation and reactive percolation of melts and fluids in producing compositional and structural heterogeneity and the feedbacks between these processes, (ii) the weak mechanical effect of mineralogical variations, and (iii) the low volumes of fine-grained microstructures and difficulty to preserve them. In contrast, olivine CPO and the resulting anisotropy of mechanical and thermal properties are only modified by deformation. Based on this analysis, we propose that strain localization at the plate scale is, at first order, controlled by large-scale variations in thermal structure and in CPO-induced anisotropy. In cold parts of the lithospheric mantle , grain size reduction may contribute to strain localization, but the low volume of fine-grained domains limits this effect

show abstract

Section: Accepted Manuscriptsupporting

confidence: 82%

Heterogeneity and anisotropy in the lithospheric mantle

2015

View full text Add to dashboard Cite

show abstract

“…regime at present with predominant sinistral-normal kinematics (Schumacher, 2002;Lopes Cardozo and Granet, 2005;Homuth et al, 2014;Bertrand et al, 2018). This makes the URG one of the seismically most active areas in Germany (Henrion et al, 2020; Figure 1C).…”

Section: Introductionmentioning

confidence: 97%

“…The model outcomes are compared to the observed distribution of seismicity ( Figure 1C) in the region (e.g., Homuth et al, 2014;Barth et al, 2015) in an attempt to understand if a causative relationship exists between the resolved variations in crustal rheology and the seismic activity in the area and to derive insights into the interaction of deformation controlling factors across the entire rift.…”

Section: Introductionmentioning

confidence: 99%

Influence of Lithosphere Rheology on Seismicity in an Intracontinental Rift: The Case of the Rhine Graben

et al. 2020

View full text Add to dashboard Cite

“…Şengör et al (1978) were the first to link the main Rhine Graben as a rift structure to the compressional stress orientation induced in the orogenic foreland by the Alpine collision, and to use it as the type example of such structures. The Lower Rhine basin displays evidence for sinistral transtension (Cardozo and Behrmann 2006) but there are numerous normal faults along which significant NE-SW extension has occurred, and earthquake focal mechanisms indicate the current stress field is similarly oriented (Homuth et al 2014).…”

Section: Rhine-type Foreland Magmatism and Extensional Structuresmentioning

confidence: 99%

Magmatism and Extension in the Foreland and Near-Trench Region of Collisional and Convergent Tectonic Systems

Schoonmaker

Kidd

Ashcroft

2016

View full text Add to dashboard Cite

Foreland magmatism occurs in the lower plate during arc–continent or continent–continent collision, although it is uncommon. Ancient examples are recognized by a stratigraphic section into which mafic lavas and/or shallow sills are emplaced at a level at the top of a passive margin cover sequence, or within the overlying deeper water deposits that include mudrocks and flysch-type turbidites. Extensional structures associated with the emplacement of the volcanic rocks may develop slightly prior to or contemporaneous with the arrival of the approaching thrust front. We have selected twelve examples of magmatism in collisional forelands, modern and ancient, and have compared the tectonic associations of the magmatism with the magmatic geochemistry. Foreland magmatic settings fall into two strikingly distinct geochemical groups: a more enriched alkaline group (Rhine-type) and a more heterogeneous tholeiitic group (Maine-type) that may show traces of prior subduction processes. In the examples where the contemporaneous extensional structures are known, faults and basins develop parallel to the thrust front for the tholeiitic group and have oblique orientations, in several cases at a high angle to the thrust front, for the alkaline group. The geochemical results are quite sufficiently distinct to permit discrimination of these two foreland magmatic rock suites from each other in ancient examples where the foreland setting is clear from geological evidence. However, magmatic products of the same range of compositions can be generated in other tectonic environments (rifts, back-arc basins), so the geochemical characteristics alone are insufficient to identify a foreland basin setting. The alkaline Rhine-type group formed primarily in response to localized upwelling convective activity from the sub-asthenospheric mantle beneath the lower plate during collision while the tholeiitic Maine-type group formed primarily in response to melting of subcontinental asthenospheric mantle during extension of the lower plate by slab pull, and resulting lithospheric detachment. It is possible that there has been a long-term secular decrease in the occurrence of the Maine-type foreland magmatism since the early Proterozoic.RÉSUMÉBien que peu fréquent, il arrive qu’un magmatisme d’avantpays se produise dans la plaque inférieure durant une collision arc-continent ou continent-continent. Des exemples anciens ont été décrits dans une coupe stratigraphique renfermant des laves mafiques et/ou des filons-couches au haut d’une séquence de couverture de marge passive, ou au sein de dépôts de plus grandes profondeurs comme des boues ou des turbidites de type flysch. Des structures d’étirement associées à la mise en place des roches volcaniques peuvent se développer un peu avant ou en même temps que l’arrivée du front de chevauchement. Nous avons choisi douze exemples de magmatisme au sein d’avant-pays de collision, modernes et anciens, et nous avons comparé les associations tectoniques du magmatisme avec la géochimie magmatique. Les configurations magmatiques d’avant-pays se divisent en deux groupes géochimiques très différents : un groupe alcalin plus enrichi (type-Rhin), et un groupe tholéiitique plus hétérogène (type-Maine) et qui peut montrer des traces de précédentes activités de subduction. Dans les exemples où les structures d’étirement contemporaines sont connues, les failles et les bassins se développent parallèlement au front de chevauchement pour le groupe tholéiitique, alors que leurs orientations sont obliques, voire à angles aigus au front de chevauchement pour le groupe alcalin. Les résultats géochimiques sont suffisamment distincts pour permettre de distinguer ces deux suites de roches magmatiques dans les exemples anciens où la configuration d’avant-pays est évidente de par sa géologie. Cependant, des produits magmatiques de même type compositionnel peuvent advenir dans d’autres environnements tectoniques (fosses, bassins d’arrière-arc), et donc, la caractérisation géochimique seule ne permet pas de distinguer une configuration de bassin d’avant-pays. Le groupe alcalin de type-Rhin s’est principalement formé en réponse à une activité d’éruption de convection issue du manteau sous-asthénosphérique sous la plaque inférieure durant la collision, alors que le groupe tholéiitique de type-Maine s’est formé principalement en réaction à la fusion du manteau sous-continental asthénosphérique durant l’extension de la plaque inférieure par étirement de la plaque, et le détachement lithosphérique qui en découle. Depuis le Protérozoïque, est possible qu’il y ait eu une décroissance progressive à long terme des événements magmatiques de type-Maine.

show abstract

Seismicity of the northern Upper Rhine Graben — Constraints on the present-day stress field from focal mechanisms

Cited by 17 publications

References 31 publications

Heterogeneity and anisotropy in the lithospheric mantle

Heterogeneity and anisotropy in the lithospheric mantle

Influence of Lithosphere Rheology on Seismicity in an Intracontinental Rift: The Case of the Rhine Graben

Magmatism and Extension in the Foreland and Near-Trench Region of Collisional and Convergent Tectonic Systems

Contact Info

Product

Resources

About