Showing papers in "Journal of Structural Geology in 1983"

TL;DR: The application of the technique of balanced section construction, initially developed for areas of compressional folding and faulting, is reviewed with reference to extensional tectonics in this article, where a number of examples are discussed where these techniques have been successfully applied in the North Sea.

TL;DR: In this article, the authors examine the kinematic behaviour of normal fault systems and see what general conditions govern their geometrical evolution, and pay particular attention to seismological and surface data from regions of present day active normal faulting.

TL;DR: In this paper, the formation of deformation bands in porous sandstones has been studied using a constitutive model, and it is shown that the deformation band instability can develop, and strain increments within the zone of deformations can become boundlessly large when the far-field stresses reach critical values.

TL;DR: In this article, the variation of displacement along fifteen traces of minor normal faults was measured in the multilayered Quaternary sediments of Kyushu, Japan, and two distinct types of faults, a cone-shaped L-D pattern (C-type) and mesa-shaped one (M-type), were detected.

TL;DR: In this paper, the Moine thrust zone of Scotland has been studied and it is shown that the variations in strain paths and non-plane strain ellipsoids can be used to delineate zones of extensional and compressional flow and differential movement in the shear zones or thrusts.

TL;DR: In this paper, a new test based on eigenvalue analysis is proposed for randomness in 3D axial orientation data, and the test statistic is S1/S3, the ratio of the largest to smallest eigenvalues of the orientation tensor.

TL;DR: In this article, the central part of the Aar Granite (Aar Valley) shows lens-shaped domains of low strain separated by anastomosing domains of high strain.

TL;DR: In this paper, the geometry of thin-skinned thrust zones, where the thrusts shallow out at depth and of thicker-skinned fault zones where much of the crust is involved, is analyzed.

TL;DR: In this article, displacement along an analogue fault model was examined under conditions of direct shear, and the experimental fracture patterns were then compared with the natural features, and it can be inferred that stresses are reoriented inside the shear zone; the angle between elementary fractures depends on their order of development; transpression and transtension zones occur systematically; and the sheer zone undergoes dilatancy under low normal stresses.

TL;DR: A theory of finite strain variation in contrasting viscous layers is presented in this paper, which is applicable to layers which are oblique to two principal strains, but parallel to the third and is not restricted to plane strain.

TL;DR: The orthographic orientation net as mentioned in this paper is a useful tool for the analysis of rank-2 tensor operations such as deformation and displacement, and it can be used to classify plane deformations.

TL;DR: The Aguilon nappe as discussed by the authors is a fold-nappe, comprising Triassic and older metasedimentary rocks, and the most prominent set of small-scale folds changes from dominantly N-vergent in the upper, right-way-up limb to S-variances in the greatly thinned lower limb.

TL;DR: In this article, the results of an attempt to identify the deformation micromechanisms in the brittle-ductile transition zone of the Alpine fault, New Zealand, were reported.

TL;DR: The foliated and compositionally-banded granitic orthogneisses in the central core of the Maggia Nappe, a Lower Pennine basement nappe of the Central Swiss Alps, are shown to be the sheared equivalent of late-Hercynian age granitic intrusions as discussed by the authors.

TL;DR: In this article, the branch-and tip-lines of a fault surface were analyzed on the Trondheim area to derive a more rigorous section which was also constrained by gravimetric, aeromagnetic and metamorphic data.

TL;DR: The foliation formed in a ductile shear zone can become folded by continuing shear in the zone without the foliation having to enter the shortening sector of the flow field as mentioned in this paper.

TL;DR: In this article, the depth to the floor thrust and shortening within imbricates above this thrust are estimated by a series of partially balanced cross-sections drawn between the synclinal median and the Valais thrust.

TL;DR: In this paper, the compatibility condition in Mohr space is that the circles for A and B should intersect in a point that represents the material line of the A/B boundary.

TL;DR: In this paper, two Hercynian duplexes are developed in Visean limestones in the Basse Normandie quarry, where the lower duplex exposes all the internal thrusts, a reference bed of chalky limestone, the roof and floor thrusts and the duplex tip.

TL;DR: In this paper, the authors described the strain distribution patterns from several naturally occurring ductile shear zone terminations and suggested a two-fold classification of termination patterns: Type I termination patterns show a symmetrical decrease in strain area and intensity, and are associated with very low shear strain (ψ) values in the main shear zones.

TL;DR: In this article, a method of strain analysis is described which takes into account a possible competence difference between the strain markers and the rest of the rock, and limits are placed on the possible effective viscosity contrast between the inclusions and the rock as a whole as well as on the bulk finite strain suffered by the rock.

TL;DR: The Batinah melange as discussed by the authors overlies the late Cretaceous Semail ophiolite in the northern Oman Mountains and comprises mostly sedimentary rocks of deep-water facies, alkalic lavas and intrusives, all of continental margin affinities, together with smaller volumes of Semail Ophiolitic and metamorphic rocks.

TL;DR: In this paper, the authors argue that vein and cleavage geometry support an origin of the veins as tension fractures in a rotated secondary stress field rather than a primary shear origin as advocated by Beach, and conclude that the veins develop in dilational shear zones under high fluid pressure.

TL;DR: In this paper, the length/width ratios of tension fractures were used to estimate the tensile stress (assumed constant along the length of each fracture) at the time of fracture formation.

TL;DR: In this article, the authors show that the technique is basically an improved Euler method for integrating differential equations, and that unstrained elements (parallelepipeds) should therefore be fitted together so that face centres of adjoining elements coincide; or where this is not possible, the interfacial distances should be minimized.

TL;DR: In this article, a finite-strain ellipsoid determination method was applied to deformed gneissic rocks, and the results showed that in some cases effects of a pretectonic fabric can be eliminated.

TL;DR: In this paper, the volume change between the various sectors of the same heterogeneously deformed layer (fold, shear zone) by comparing the chemical composition of deformed sectors with that of a reference sector is presented.

TL;DR: In this article, a review of the patterns of finite strain in some Alpine nappes and thrust sheets are reviewed, together with their tectonic evolution, and the finite-strain pattern resulted from successive diagenetic compaction, multilayer buckling and heterogeneous simple shear.

TL;DR: In this article, the authors proposed a method for estimating cumulative strain in glaciers using numerical methods, which is difficult to measure in ice, but numerical methods provide a good means of estimating cumulative strains.