| 1. |
- Bayer, R, et al.
(författare)
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Active deformation in Zagros-Makran transition zone inferred from GPS measurements
- 2006
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Ingår i: Geophysical Journal International. ; 165:1, s. 373-381
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Tidskriftsartikel (refereegranskat)abstract
- The Bandar Abbas-Strait of Hormuz zone is considered as a transition between the Zagros collision and the Makran oceanic subduction. We used GPS network measurements collected in 2000 and 2002 to better understand the distribution of the deformation between the collision zone and the Makran subduction. Analysing the GPS velocities, we show that transfer of the deformation is mainly accommodated along the NNW–SSE-trending reverse right-lateral Zendan–Minab–Palami (ZMP) fault system. The rate is estimated to 10 ± 3 mm yr−1 near the faults. Assuming that the ZMP fault system transfers the motion between the Makran–Lut Block and the Arabian plate, we estimate to 15 mm yr−1 and 6 mm yr−1, respectively, the dextral strike-slip and shortening components of the long-term transpressive displacement. Our geodetic measurements suggest also a 10–15 km locking depth for the ZMP fault system. The radial velocity pattern and the orientation of compressive strain axes around the straight of Hormuz is probably the consequence of the subducting Musandam promontory. The N–S Jiroft–Sabzevaran (JS) fault system prolongates southwards the dextral shear motion of the Nayband–Gowk (NG) fault system at an apparent rate of 3.1 ± 2.5 mm yr−1. The change from strong to weak coupling for underthrusting the Arabian plate beneath the Zagros (strong) and the Makran (weak) may explain the dextral motion along the ZMP, JS/NG and Neh–Zahedan fault systems which transfer the convergence from a broad zone in the western Iran (Zagros, Tabriz fault system, Alborz, Caucasus and Caspian sea surroundings) to Makran subduction.
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| 2. |
- Walpersdorf, A, et al.
(författare)
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Difference in the GPS deformation pattern of North and Central Zagros (Iran)
- 2006
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Ingår i: Geophysical Journal International. - 0956-540X .- 1365-246X. ; 167:3, s. 1077-1088
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Tidskriftsartikel (refereegranskat)abstract
- Measurements on either side of the Kazerun fault system in the Zagros Mountain Belt, Iran, show that the accommodation of the convergence of the Arabian and Eurasian Plates differs across the region. In northwest Zagros, the deformation is partitioned as 3–6 mm yr−1 of shortening perpendicular to the axis of the mountain belt, and 4–6 mm yr−1 of dextral strike-slip motion on northwest–southeast trending faults. No individual strike-slip fault seems to slip at a rate higher than ∼2 mm yr−1. In southeast Zagros, the deformation is pure shortening of 8 ± 2 mm yr−1 occurring perpendicular to the simple folded belt and restricted to the Persian Gulf shore. The fact that most of the deformation is located in front of the simple folded belt, close to the Persian Gulf, while seismicity is more widely spread across the mountain belt, confirms the decoupling of the surface sedimentary layers from the seismogenic basement. A comparison with the folding and topography corroborates a southwestward propagation of the surface deformation. The difference in deformation between the two regions suggests that right-lateral shear cumulates on the north–south trending Kazerun strike-slip fault system to 6 ± 2 mm yr−1.
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| 3. |
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| 4. |
- Schreurs, G., et al.
(författare)
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Analogue benchmarks of shortening and extension experiments
- 2006. - 253
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Ingår i: <em> </em>Analogue and Numerical Modeling of Crustal-Scale Processes. - : Geological Society of London. - 1862391912 ; , s. 1-27
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Bokkapitel (refereegranskat)abstract
- We report a direct comparison of scaled analogue experiments to test thereproducibility of model results among ten different experimental modelling laboratories.We present results for two experiments: a brittle thrust wedge experiment and a brittleviscousextension experiment. The experimental set-up, the model construction technique,the viscous material and the base and wall properties were prescribed. However, each laboratoryused its own frictional analogue material and experimental apparatus. Comparisonof results for the shortening experiment highlights large differences in model evolutionthat may have resulted from (1) differences in boundary conditions (indenter or basal-pullmodels), (2) differences in model widths, (3) location of observation (for example, sidewallversus centre of model), (4) material properties, (5) base and sidewall frictional properties,and (6) differences in set-up technique of individual experimenters. Six laboratories carriedout the shortening experiment with a mobile wall. The overall evolution of their models isbroadly similar, with the development of a thrust wedge characterized by forward thrustpropagation and by back thrusting. However, significant variations are observed inspacing between thrusts, their dip angles, number of forward thrusts and back thrusts, andsurface slopes. The structural evolution of the brittle-viscous extension experiments issimilar to a high degree. Faulting initiates in the brittle layers above the viscous layer in close vicinity to the basal velocity discontinuity. Measurements of fault dip angles and faultspacing vary among laboratories. Comparison of experimental results indicates an encouragingoverall agreement in model evolution, but also highlights important variations in thegeometry and evolution of the resulting structures that may be induced by differences inmodelling materials, model dimensions, experimental set-ups and observation location
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