Emplacement of a radiating dike swarm in western Vinmara Planitia, Venus: interpretation of the regional stress field orientation and subsurface magmatic configuration

1994 ◽  
Vol 66 (2) ◽  
pp. 153-171 ◽  
Author(s):  
Eric B. Grosfils ◽  
James W. Head
Keyword(s):  
Stress Field ◽  
Field Orientation ◽  
Regional Stress ◽  
Dike Swarm ◽  
Regional Stress Field

Stress-field orientation and crustal deformation in the Vienna Basin region (Alpine-Pannonian-Carpathian junction)

2020 ◽  
Author(s):  
Sven Schippkus ◽  
Dimitri Zigone ◽  
Götz Bokelmann ◽  
AlpArray Working Group
Keyword(s):  
Stress Field ◽  
Numerical Modelling ◽  
Crustal Deformation ◽  
Azimuthal Anisotropy ◽  
Field Orientation ◽  
Regional Stress ◽  
Fault Systems ◽  
Lateral Extrusion ◽  
Regional Stress Field ◽  
Insight Into

<p>Gaining insight into the regional stress field and deformation in the crust is challenging. As we cannot measure these directly, we rely on proxy measurements and numerical modelling to infer their orientation. For the Alpine-Pannonian-Carpathian junction, only a limited number of studies exist that provide such insights. They are based on either the interpretation of sparse and point-wise measurements of local stress-field orientations or on numerical modelling that aims to satisfy tectonic and geological constraints.</p><p> </p><p>We infer seismic azimuthal anisotropy that relates to the orientation of the regional stress-field and crustal deformation from ambient-noise-derived Rayleigh waves in the region. This approach provides a spatially broad and independent measurement that complements previous studies. We use Rayleigh-wave group-velocity residuals after isotropic inversion at 5s and 20s center period, which are sensitive to crustal structure at different depths. They allow us to gain insight into two distinct mechanisms that result in fast orientations. At shallow crustal depths (5s), fast orientations in the region are N/S to NNE/SSW, roughly normal to the Alps. This effect is most likely due to the formation of cracks aligned with the present-day stress field. At greater depths (20s), fast orientations rotate towards NE, almost parallel to the major fault systems that accommodated the lateral extrusion of blocks in the Miocene. This is coherent with the expected direction of aligned crystal grains during crustal deformation occurring along the fault systems and the lateral extrusion of the central part of the Eastern Alps.</p>

Two key switches in regional stress field during multi-stage deformation in the Carboniferous−Triassic southernmost Altaids (Beishan, NW China): Response to orocline-related roll-back processes

2021 ◽  
Author(s):  
Zhonghua Tian ◽  
Wenjiao Xiao ◽  
Brian F. Windley ◽  
Peng Huang ◽  
Ji’en Zhang ◽  
...  
Keyword(s):  
Stress Field ◽  
Large Scale ◽  
Electron Backscatter Diffraction ◽  
Volcanic Rocks ◽  
Structural Deformation ◽  
Regional Stress ◽  
Regional Stress Field ◽  
Multi Stage ◽  
Beishan Orogenic Collage ◽  
Roll Back

The orogenic architecture of the Altaids of Central Asia was created by multiple large-scale slab roll-back and oroclinal bending. However, no regional structural deformation related to roll-back processes has been described. In this paper, we report a structural study of the Beishan orogenic collage in the southernmost Altaids, which is located in the southern wing of the Tuva-Mongol Orocline. Our new field mapping and structural analysis integrated with an electron backscatter diffraction study, paleontology, U-Pb dating, 39Ar-40Ar dating, together with published isotopic ages enables us to construct a detailed deformation-time sequence: During D1 times many thrusts were propagated northwards. In D2 there was ductile sinistral shearing at 336−326 Ma. In D3 times there was top-to-W/WNW ductile thrusting at 303−289 Ma. Two phases of folding were defined as D4 and D5. Three stages of extensional events (E1−E3) separately occurred during D1−D5. Two switches of the regional stress field were identified in the Carboniferous to Early Permian (D1-E1-D2-D3-E2) and Late Permian to Early Triassic (D4-E3-D5). These two switches in the stress field were associated with formation of bimodal volcanic rocks, and an extensional interarc basin with deposition of Permian-Triassic sediments, which can be related to two stages of roll-back of the subduction zone on the Paleo-Asian oceanic margin. We demonstrate for the first time that two key stress field switches were responses to the formation of the Tuva-Mongol Orocline.

scholarly journals Recent inversion of the Tyrrhenian Basin

Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 123-127 ◽  
Author(s):  
Nevio Zitellini ◽  
César R. Ranero ◽  
M. Filomena Loreto ◽  
Marco Ligi ◽  
Marco Pastore ◽  
...  
Keyword(s):  
Stress Field ◽  
Driving Mechanism ◽  
Extensional Tectonics ◽  
Seismic Profiles ◽  
Regional Stress ◽  
Regional Stress Field ◽  
Slab Rollback ◽  
New Finding ◽  
Subduction System ◽  
Tyrrhenian Basin

Abstract The Tyrrhenian Basin is a region created by Neogene extensional tectonics related to slab rollback of the east-southeast–migrating Apennine subduction system, commonly believed to be actively underthrusting the Calabrian arc. A compilation of >12,000 km of multichannel seismic profiles, much of them recently collected or reprocessed, provided closer scrutiny and the mapping of previously undetected large compressive structures along the Tyrrhenian margin. This new finding suggests that Tyrrhenian Basin extension recently ceased. The ongoing compressional reorganization of the basin indicates a change of the regional stress field in the area, confirming that slab rollback is no longer a driving mechanism for regional kinematics, now dominated by the Africa-Eurasia lithospheric collision

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