Dextral strike-slip along the Kapıdağ shear zone (NW Turkey): evidence for Eocene westward translation of the Anatolian plate

The Lardeau Group is a heterogeneous assemblage of lower Paleozoic eugeoclinal strata present in the Kootenay Arc in southeastern British Columbia. It is in fault contact with lower Paleozoic miogeoclinal strata for all or some of its length along a structure termed the Lardeau shear zone. The Lardeau Group was deformed prior to mid-Mississippian time, as manifested by layer-parallel faults, folds, and evidence for early greenschist-facies metamorphism. Regional constraints indicate probable Devono-Mississippian timing of orogeny, and possible juxtaposition of the Lardeau Group over miogeoclinal strata along the Lardeau shear zone at this time. Further ductile deformation during the Middle Jurassic Columbian orogeny produced large folds with subhorizontal axes, northwest-striking foliation and faults, and orogen-parallel stretching lineations. This deformation was apparently not everywhere synchronous, and may have continued through Late Jurassic time northeast of Trout Lake. This was followed by Cretaceous(?) dextral strike-slip and normal movement on the Lardeau shear zone and other parallel faults. While apparently the locus of several episodes of faulting, the Lardeau shear zone does not record the accretion of far-travelled tectonic fragments, as sedimentological evidence ties the Lardeau Group and other outboard units to the craton.

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Structural Overview and Morphotectonic Evolution of a Strike-Slip Fault in the Zone of North Almora Thrust, Central Kumaun Himalaya, India

Journal of Geological Research ◽

10.1155/2016/6980943 ◽

2016 ◽

Vol 2016 ◽

pp. 1-16 ◽

Cited By ~ 5

Author(s):

Lalit M. Joshi ◽

Pitamber D. Pant ◽

Bahadur S. Kotlia ◽

Girish C. Kothyari ◽

Khayingshing Luirei ◽

...

Keyword(s):

Shear Zone ◽

Strike Slip ◽

Strike Slip Fault ◽

Asymmetry Factor ◽

Base Line ◽

Gradient Index ◽

River Channels ◽

Fluvial Terraces ◽

Dextral Strike Slip Fault ◽

Dextral Strike Slip

The aim of the present research is to provide the base line details of the NNW-SSE trending Raintoli fault (RF) which is running parallel to the North Almora Thrust (NAT) along the Saryu valley from Seraghat-Naichun to Seri in the central sector of the Uttarakhand Himalaya, India. The RF is characterized as dextral strike slip fault and behaves as a ductile shear zone within the zone of NAT. The dextral sense of shear movement of RF is delineated by the fabric of the shear zone rocks including microscopically observed indicators such as sigma and delta porphyroclasts, quartz c-axis, and the field structural data. Additionally, in the quaternary period the dextral strike slip fault is reactivated with oblique slip component as characterized by various geomorphic indicators, for example, triangular facets, abandoned river channels, unpaired fluvial terraces, and V-shaped valleys with recurrent seismicity. Further, the morphometric parameters including Valley Floor Width to Valley Height (Vf), asymmetry factor (AF), and gradient index (GI) further prove active nature of RF as suggested by low values of hypsometric integration, V-shaped valley, higher gradient index, and tilting of Saryu basin.

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Kinematic partitioning in the Southern Andes (39° S–46° S) inferred from lineament analysis and reassessment of exhumation rates

International Journal of Earth Sciences ◽

10.1007/s00531-021-02068-y ◽

2021 ◽

Author(s):

Paul Leon Göllner ◽

Jan Oliver Eisermann ◽

Catalina Balbis ◽

Ivan A. Petrinovic ◽

Ulrich Riller

Keyword(s):

Fault Zone ◽

Vertical Displacement ◽

Strike Slip ◽

Structural Studies ◽

Southern Andes ◽

Plate Convergence ◽

Exhumation Rates ◽

Lineament Analysis ◽

Dextral Strike Slip ◽

Data Call

AbstractThe Southern Andes are often viewed as a classic example for kinematic partitioning of oblique plate convergence into components of continental margin-parallel strike-slip and transverse shortening. In this regard, the Liquiñe-Ofqui Fault Zone, one of Earth’s most prominent intra-arc deformation zones, is believed to be the most important crustal discontinuity in the Southern Andes taking up margin-parallel dextral strike-slip. Recent structural studies, however, are at odds with this simple concept of kinematic partitioning, due to the presence of margin-oblique and a number of other margin-parallel intra-arc deformation zones. However, knowledge on the extent of such zones in the Southern Andes is still limited. Here, we document traces of prominent structural discontinuities (lineaments) from the Southern Andes between 39° S and 46° S. In combination with compiled low-temperature thermochronology data and interpolation of respective exhumation rates, we revisit the issue of kinematic partitioning in the Southern Andes. Exhumation rates are maximal in the central parts of the orogen and discontinuity traces, trending predominantly N–S, WNW–ESE and NE–SW, are distributed across the entire width of the orogen. Notably, discontinuities coincide spatially with large gradients in Neogene exhumation rates and separate crustal domains characterized by uniform exhumation. Collectively, these relationships point to significant components of vertical displacement on these discontinuities, in addition to horizontal displacements known from published structural studies. Our results agree with previously documented Neogene shortening in the Southern Andes and indicate orogen-scale transpression with maximal vertical extrusion of rocks in the center of the transpression zone. The lineament and thermochronology data call into question the traditional view of kinematic partitioning in the Southern Andes, in which deformation is focused on the Liquiñe-Ofqui Fault Zone.

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Coseismic fault-slip distribution of the 2019 Ridgecrest Mw6.4 and Mw7.1 earthquakes

Scientific Reports ◽

10.1038/s41598-021-93521-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yang Gao ◽

HuRong Duan ◽

YongZhi Zhang ◽

JiaYing Chen ◽

HeTing Jian ◽

...

Keyword(s):

Strike Slip ◽

Fault Slip ◽

Slip Distribution ◽

Synthetic Aperture ◽

Seismic Events ◽

Interferometric Synthetic Aperture Radar ◽

The Past ◽

Dextral Strike Slip Fault ◽

Fault Slip Distribution ◽

Dextral Strike Slip

AbstractThe 2019 Ridgecrest, California seismic sequence, including an Mw6.4 foreshock and Mw7.1 mainshock, represent the largest regional seismic events within the past 20 years. To obtain accurate coseismic fault-slip distribution, we used precise positioning data of small earthquakes from January 2019 to October 2020 to determine the dip parameters of the eight fault geometry, and used the Interferometric Synthetic Aperture Radar (InSAR) data processed by Xu et al. (Seismol Res Lett 91(4):1979–1985, 2020) at UCSD to constrain inversion of the fault-slip distribution of both earthquakes. The results showed that all faults were sinistral strike-slips with minor dip-slip components, exception for dextral strike-slip fault F2. Fault-slip mainly occurred at depths of 0–12 km, with a maximum slip of 3.0 m. The F1 fault contained two slip peaks located at 2 km of fault S4 and 6 km of fault S5 depth, the latter being located directly above the Mw7.1hypocenter. Two slip peaks with maximum slip of 1.5 m located 8 and 20 km from the SW endpoint of the F2 fault were also identified, and the latter corresponds to the Mw6.4 earthquake. We also analyzed the influence of different inversion parameters on the fault slip distribution, and found that the slip momentum smoothing condition was more suitable for the inversion of the earthquakes slip distribution than the stress-drop smoothing condition.

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The Caledonoid faults of northern Lleyn (North Wales)

Geological Magazine ◽

10.1017/s0016756800055710 ◽

1970 ◽

Vol 107 (3) ◽

pp. 235-247 ◽

Cited By ~ 4

Author(s):

W. E. Tremlett

Keyword(s):

Volcanic Rocks ◽

Strike Slip ◽

Metamorphic Rocks ◽

Red Sandstone ◽

North Wales ◽

Dextral Strike Slip

SummaryEvidence of substantial dextral strike-slip displacements along the Caledonoid fault-set of northern Lleyn is revealed by the distribution of Pre-Cambrian igneous and metamorphic rocks, Ordovician volcanic rocks and Caledonian ‘early granodioritic’ intrusions. These apparently occurred prior to some smaller sinistral strike-slip movements which left total net dextral displacements of 91/2 km. Both types of movement were completed before the Caledonoid faults were disrupted by NNW sinistral faulting and more intrusions of Lower Old Red Sandstone age were emplaced.

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Acadian strike-slip tectonics in the Gaspé region, Quebec Appalachians

Canadian Journal of Earth Sciences ◽

10.1139/e89-149 ◽

1989 ◽

Vol 26 (9) ◽

pp. 1764-1777 ◽

Cited By ~ 24

Author(s):

Michel Malo ◽

Jacques Béland

Keyword(s):

Middle Devonian ◽

High Strain ◽

Structural Features ◽

Fault Zones ◽

Strike Slip ◽

Structural Units ◽

Middle Ordovician ◽

Southern Margin ◽

Intense Deformation ◽

Dextral Strike Slip

At the southern margin of the Cambro-Ordovician Humber Zone in the Quebec Appalachians, on Gaspé Peninsula, three structural units of Middle Ordovician to Middle Devonian cover rocks of the Gaspé Belt are in large part bounded by long, straight longitudinal faults. In one of these units, the Aroostook–Percé anticlinorium, several structural features, which can be ascribed to Acadian deformation, are controlled by three subparallel, dextral, strike-slip longitudinal faults: Grande Rivière, Grand Pabos, and Rivière Garin. These faults follow bands of intense deformation, contrasting with the mildly to moderately deformed intervals that separate them.Most of the structural features observed – rotated oblique folds and cleavage, subsidiary Riedel and tension faults, and offsets of markers – can be integrated in a model of strike-slip tectonics that operated in ductile–brittle conditions. A late increment of deformation in the form of conjugate cleavages and minor faults is restricted to the bands of high strain. An anticlockwise transection of the synfolding cleavage in relation to the oblique hinges may be a feature of the rotational deformation.The combined dextral strike slip that can be measured within the three major longitudinal fault zones amounts to 138 km, to which can be added 17 km of ductile movement in the intervals, for a total of 155 km.

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The northern Appalachian terrane wreck model

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2020-0114 ◽

2021 ◽

pp. 1-12

Author(s):

J. Duncan Keppie ◽

D. Fraser Keppie ◽

Jaroslav Dostal

Keyword(s):

Lower Devonian ◽

Strike Slip ◽

Late Devonian ◽

Backarc Basin ◽

Clockwise Rotation ◽

Rheic Ocean ◽

Magmatic Rocks ◽

Younger Age ◽

The Common ◽

Dextral Strike Slip

Ordovician and Siluro-Lower Devonian magmatic rocks in the northern Appalachians south of the Iapetus suture are currently interpreted as distinct belts composed of multiple, small, peri-Gondwanan terranes that amalgamated during the sequential closures of Iapetus (latest Ordovician), the Tetagouche backarc basin (early Silurian), the Acadian seaway (Siluro-Devonian), and the Rheic Ocean (Devono-Carbonferous) (multiple terrane model). Here, the Siluro-Lower Devonian magmatic belts are shown to have slab failure affinities and together with the Ordovician arcs form paired belts parallel to the Iapetus suture, which suggests that they were emplaced along the common, peri-Avalonian margin during pre- and post-collisional processes. The Iapetan suture and the paired belts are inferred to repeat in Atlantic Canada due to dextral, strike-slip processes of mid-Late Devonian or younger age (terrane wreck model). In Newfoundland, the repetition is inferred to be the result of oblique, dextral offset of ca. 250 km. In the Quebec Embayment, the Iapetan paired magmatic belts are repeated twice in the limbs of a Z-shaped orocline related to oblique, dextral offsets of ca. 1200 km of the southern limb. Limited Siluro-Devonian paleomagnetic data indicate no paleolatitudinal differences across the Iapetus suture, however ca. 100° post-mid Silurian clockwise rotation is indicated for the middle fold limb; these data favour the terrane wreck model. The terrane wreck model results in a simple tectonic scenario of southerly subduction of Iapetus beneath a single ribbon continent (Avalonia sensu lato) that was subsequently deformed.

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