Strain partitioning and relief segmentation in arcuate fold-and-thrust belts: a case study from the western Betics

A. Jiménez-Bonilla; I. Expósito; J. C. Balanyá; M. Díaz-Azpiroz

doi:10.1007/s41513-017-0028-0

Integration of Surface Geological and Seismic Data for Prospect Analysis in Fold and Thrust Belts: Case Study from NW Kurdistan, Iraq

10.1190/ist092012-001.15 ◽

2012 ◽

Author(s):

Peter Keller ◽

Jürgen Hoffmann ◽

Ali Chalabi ◽

Nils Bang

Keyword(s):

Seismic Data ◽

Thrust Belts ◽

Fold And Thrust Belts

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Analogue models of progressive arcs: strain partitioning and localization in fold-and-thrust belts developed over ductile layer of different geometry

10.5194/egusphere-egu2020-7358 ◽

2020 ◽

Author(s):

Alejandro Jiménez-Bonilla ◽

Ana Crespo ◽

Inmaculada Expósito ◽

Juan Carlos Balanyá ◽

Manuel Díaz-Azpíroz ◽

...

Keyword(s):

Strike Slip ◽

Main Trend ◽

Sand Layer ◽

Strain Partitioning ◽

Thrust Belts ◽

Brittle Layer ◽

Analogue Models ◽

Fold And Thrust Belts ◽

Thrust System ◽

Ductile Layer

Although analogue models have successfully simulated many different types of arcuate fold-and-thrust belts, we were able to design a backstop whose curvature ratio diminished and its protrusion grade increased during experiments reproducing several kinematic features of progressive arcs never seen before 2016. General models were made up of an homogeneous silicone layer, where detachments tend to localize, overlain by a sand layer. They accomplished to simulate the overall structure and kinematics of fold-and-thrust belts of Mediterranean Arcs, especially that of the Gibraltar arc: (1) highly divergent thrust transport directions, (2) arc-perpendicular normal and strike-slip faults accommodating arc-lengthening, (3) transpressive and transtensional bands oblique to the main trend located in the lateral zones, (4) vertical axis-rotations up to 70&#186; and (5) block individualization that rotated independently clockwise and counterclockwise in the left and right arc limbs, respectively.However, the ductile layer is neither continuous nor homogeneous in natural cases, such that pinch-outs and diapirs previous to deformation are frequently found across and along strike. Thus, we have modified our original set-up including silicone pinch-outs and different sizes of silicone diapirs. Where silicone pinch-outs were subparallel to the apex movement, differences in the structural style along the foreland thrust-belt occurred. A forward thrust system over frictional detachments (no silicone), or wide, double verging thrust-systems over ductile detachments (with silicone) developed. Differential displacement between both types of thrust-belts was accommodated by transfer zones. Where silicone pinch-outs were perpendicular to the apex movement, the deformation front propagated up to the pinch-out, where it stopped and the thrust-system thickened up to its subsequent collapse. In models with pre-existing diapirs, first thrust and strike-slip faults nucleated close to diapirs and linked them. When deformation proceeded, all diapirs were added and deformed within the fold-and-thrust belts.We also made experiments to analyze the ductile deformation and the influence of the brittle layer (sand) thickness. In only silicone models, a homogeneous deformation was observed at the grid scale, where each square was deformed by mostly simple shear in the lateral parts whilst by mostly pure shear in its most frontal part of the models. When a sand layer was sieved on top of the silicone layer, discrete structures developed. Although all models showed strain partitioning between arc-perpendicular shortening and arc-parallel stretching, as the brittle layer thickness increased, fold wavelength increased.All these models show the high complexity derived from the different strain partitioning modes and the strain localization along and across-strike fold-and-thrust belts in progressive arcs. They can be extremely helpful to better understand this kind of arcuate orogens that are also the most frequent in nature. Even though these models were previously carried out to simulate the evolution of fold-and-thrust belts of Mediterranean arcs, they can also shed lights for the evolution of many others progressive arcs.

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Challenges of structural diagenesis in foreland fold-and-thrust belts: A case study on paleofluid flow in the Canadian Rocky Mountains West of Calgary

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2012.02.014 ◽

2012 ◽

Vol 35 (1) ◽

pp. 235-251 ◽

Cited By ~ 19

Author(s):

Veerle Vandeginste ◽

Rudy Swennen ◽

Melanie Allaeys ◽

Rob M. Ellam ◽

Kirk Osadetz ◽

...

Keyword(s):

Rocky Mountains ◽

Canadian Rocky Mountains ◽

Thrust Belts ◽

Fold And Thrust Belts

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Impact of mechanical stratification on the structural style of the Lublin Basin, SE Poland: results of seismic interpretation and implications for quantification of deformation within the frontal parts of thin-skinned fold-and-thrust belts

International Journal of Earth Sciences ◽

10.1007/s00531-021-02140-7 ◽

2021 ◽

Author(s):

Mateusz Kufrasa ◽

Piotr Krzywiec

Keyword(s):

Seismic Interpretation ◽

Upper Devonian ◽

Strain Partitioning ◽

Se Poland ◽

Structural Style ◽

Thrust Belts ◽

Fold And Thrust Belts ◽

Internal Homogeneity ◽

Lithological Composition ◽

Seismic Reflectors

AbstractWe demonstrate how lithological and mechanical stratification of Ediacaran–Carboniferous sedimentary package governs strain partitioning in the Lublin Basin (LB) which was incorporated in the marginal portion of the Variscan fold-and-thrust belt. Based on the geometry of seismic reflectors, the pre-Permian–Mesozoic sedimentary sequence was subdivided into two structural complexes differing in structural style. The lower one reveals forelandward-vergent imbrication, while the upper one comprises fold train, second-order deformations, and multiple local detachments. Lithological composition of the upper structural complex controlled geometry, kinematics, and position of compressional deformations in stratigraphic profile. System of foreland-vergent thrusts which links lower and upper detachment developed due to efficiency of simple shear operating in heterogeneous clastic-carbonate-evaporitic strata of the Lower–Upper Devonian age. Internal homogeneity promoted the formation of conjugate sets of thrusts in Silurian shales and Upper Devonian limestones. Structural seismic interpretation combined with sequential restoration revealed localised thickening of Devonian strata and up to 5% difference in length of Devonian horizons. This mismatch is interpreted as a manifestation of distributed shortening, including layer-parallel shortening (LPS), which operated before or synchronously to the initiation of folding. The amount of distributed strain is comparable with numbers obtained in external parts of other fold-and-thrust belts. The outcomes derived from this study may act as a benchmark for studying variability in a structural style of multilayered sequences which were incorporated in the external portion of other fold-and-thrust belts.

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