Transected folds and transpression: how are they associated?

Treagus, Susan H.; Treagus, J. E.

doi:10.1016/0191-8141(92)90092-b

Cited by 57 publications

(8 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Locally, the early developed foliation is refolded by synschistose noncylindrical folds with steeply to subhorizontally plunging hinges, which become subparallel to horizontal stretching lineations with increasing finite strain. These features are consistent with progressive folding in transpressional shear zones [ Fossen and Tikoff , 1998; Treagus and Treagus , 1992].…”

Section: Cretaceous Polyphase Structural Evolution: Collisional Stagementioning

confidence: 77%

Cretaceous collision and indentation in the West Carpathians: View based on structural analysis and numerical modeling

2003

View full text Add to dashboard Cite

[1] A model of indentation of a rigid promontory into weak metasedimentary rocks during Cretaceous convergence is suggested for tectonic evolution of southern part of West Carpathians. An early arcuate cleavage fan has developed in front of northward moving southern rigid basement block. The interaction of the moving indenter with western stationary basement promontory is responsible for development of the boundary-parallel shear zone along which the main southern indenter is shifted to the east. This results in development of a new steep transpressional cleavage overprinting the early fabric. Eastward displacement of the southern indenter causes the development of a thrust zone parallel to the margin of the eastern stationary promontory. A proposed numerical model of the deformation of a thin viscous sheet in front of oval rigid indenter reliably simulates the development of the observed deformation pattern. Modeled discrete partitioning between the western promontory and the indenting block fully agrees with the observed secondary cleavage associated with the transpressional shear zone. Our numerical model interconnects this complex kinematic frame with finite strain pattern, which was to date possible only for simple boundary conditions. In addition, the model explains the polyphase cleavage patterns in terms of complex shapes of promontories and changes in movements of indenting blocks.

show abstract

Section: Cretaceous Polyphase Structural Evolution: Collisional Stagementioning

confidence: 77%

Cretaceous collision and indentation in the West Carpathians: View based on structural analysis and numerical modeling

2003

View full text Add to dashboard Cite

show abstract

“…It is at the origin of overlapping folds (Moody & Hill 1956; Wilcox et al 1973; Keller et al 1997). Their orientation generally forms an angle of 45° with the basal discontinuity (Wilson 1970; Graham 1978; Odonne & Vialon 1987; Richard et al 1991) and an angle of 90° with the maximal shortening axis (Flinn 1962; Treagus & Treagus 1992). The overlapping folding observed inside the Herrère plain suggests the presence of a crustal discontinuity located below the southern end of the folds, that is, close to the main spilite outcrops (Figs 3a and 4).…”

Section: Structural Interpretationmentioning

confidence: 99%

A structural model for the seismicity of the Arudy (1980) epicentral area (Western Pyrenees, France)

Dubos-Sallée

Nivière

Lacan

et al. 2007

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YThe Western Pyrenees presents a diffuse and moderate (M ≤ 5.7) instrumental seismicity. It nevertheless historically suffered from strong earthquakes (I = IX MSK). The seismic sources of these events are not yet clearly identified. We focus on the Arudy (1980) epicentral area (M = 5.1) and propose here the reactivation of early Cretaceous normal faults of the Iberian margin as a potential source. The late Cretaceous inversion of this basin, first in a left-lateral strike-slip mode and then in a more frontal convergence, resulted in a pop-up geometry. This flower structure attests of the presence of a deep crustal discontinuity.The present-day geodynamic arrangement suggests that this accident is reactivated in a right lateral mode. This reactivation leads to a strain partitioning between the deep discontinuity that accommodates the lateral component of the motion and shallow thrusts, rooted on this discontinuity. These thrusts accommodate the shortening component of the strain. The distribution of the instrumental seismicity fits well the structural model of the Arudy basin. Whatever the compressive regional context, the structural behaviour of the system explains too the extensive stress tensor determined for the Arudy crisis if we interpret it in terms of strain ellipsoid. Indeed numerical modelling has shown that this concomitant activity of strike-slip and thrust faulting results in an extensive component that can rise 50 per cent of the finite strain.We identify too a 25-30 km long potential seismic source for the Arudy area. The size of the structure and its potential reactivation in a strike-slip mode suggest that a maximum earthquake magnitude of ∼6.5 could be expected. The extrapolation of this model at the scale of the Western Pyrenees allows to propose other potential sources for major regional historical earthquakes.

show abstract

“…6). In all cases observed, the transection is clockwise, suggesting a component of dextral strike-slip (Borradaile 1978;Treagus & Treagus 1992). However, both cleavage and folds show too much variability from place to place for transection to be clearly demonstrable from simple plots of fold and cleavage orientations.…”

Section: Cleavagementioning

confidence: 83%

Transpressional structures on a Late Palaeozoic intracontinental transform fault, Canadian Appalachians

Waldron

Roselli

Johnston

2007

View full text Add to dashboard Cite

The east-west Minas fault zone, separating the Early Palaeozoic Meguma and Avalon terranes of the Appalachians, experienced dextral strike-slip motion during the Carboniferous. Abundant oblique contractional structures indicate localized dextral transpression, immediately south of the zone, probably associated with a restraining bend. Subsurface data indicate that the deformed Horton Group clastic rocks are thrust above younger Windsor Group evaporites.Excellent exposures on wave-cut platforms of the Bay of Fundy show structures developed in transpression, including NE-trending upright and inclined folds; south-verging thrust and reverse faults; and NW-striking normal faults. Northwest-trending boudins, which are perpendicular and slightly rotated in a clockwise sense relative to fold hinges, provide a field indicator for dextral transpression. The earliest folds (F 1 ) are curvilinear and may have formed by deformation of wet sediment. F 2 tectonic folds show weak axial-planar cleavage. Locally, these have been rotated into reclined orientations; spectacular downward-facing folds are probably due to refolding by more east-west F 3 folds. The structures observed are consistent with pure-shear-dominated transpression, with the local angle of convergence a increasing over time. This strain history is compatible with progressive strain partitioning, probably associated with the spreading of topography developed at the restraining bend. Regional geological settingSouth of the Minas fault zone, the Meguma terrane is characterized by a thick (.10 km) succession of Cambrian -Ordovician metasedimentary rocks, the Meguma Group, overlain by a Late Ordovician to

show abstract

Transected folds and transpression: how are they associated?

Cited by 57 publications

References 40 publications

Cretaceous collision and indentation in the West Carpathians: View based on structural analysis and numerical modeling

Cretaceous collision and indentation in the West Carpathians: View based on structural analysis and numerical modeling

A structural model for the seismicity of the Arudy (1980) epicentral area (Western Pyrenees, France)

Transpressional structures on a Late Palaeozoic intracontinental transform fault, Canadian Appalachians

Contact Info

Product

Resources

About