scholarly journals Active dextral strike-slip faulting records termination of the Walker Lane belt at the southern Cascade arc in the Klamath graben, Oregon, USA

Geosphere ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 882-900 ◽  
Author(s):  
Trevor S. Waldien ◽  
Andrew J. Meigs ◽  
Ian P. Madin
Keyword(s):  
Strike Slip ◽  
Cascade Arc ◽  
Walker Lane ◽  
Walker Lane Belt ◽  
Dextral Strike Slip

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

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.

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

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.

The Caledonoid faults of northern Lleyn (North Wales)

1970 ◽  
Vol 107 (3) ◽  
pp. 235-247 ◽  
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.

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

1989 ◽  
Vol 26 (9) ◽  
pp. 1764-1777 ◽  
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.

The northern Appalachian terrane wreck model

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.

New Evidence of the Dextral Strike-Slip Movement in the Liaohe Basin, China: Results from Sem Experiments

2001 ◽  
Vol 44 (6) ◽  
pp. 779-784
Author(s):  
Jia-Zeng SHAN ◽  
Hong-Jun SUN ◽  
Qian-Hua XIAO ◽  
Dao-Jing WANG ◽  
Kun XU ◽  
...  
Keyword(s):  
Strike Slip ◽  
Liaohe Basin ◽  
New Evidence ◽  
Dextral Strike Slip ◽  
Strike Slip Movement

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

2016 ◽  
Vol 105 (7) ◽  
pp. 2061-2073 ◽  
Author(s):  
Ercan Türkoğlu ◽  
Gernold Zulauf ◽  
Jolien Linckens ◽  
Timur Ustaömer
Keyword(s):  
Shear Zone ◽  
Strike Slip ◽  
Nw Turkey ◽  
Dextral Strike Slip

Miocene to Messinian deformation and hydrothermal activity in a pre-Alpine basement massif of the French western Alps: new U-Th-Pb and argon ages from the Lauzière massif

2010 ◽  
Vol 181 (3) ◽  
pp. 227-241 ◽  
Author(s):  
Dominique Gasquet ◽  
Jean-Michel Bertrand ◽  
Jean-Louis Paquette ◽  
Jérémie Lehmann ◽  
Gueorgui Ratzov ◽  
...  
Keyword(s):  
Late Miocene ◽  
Shear Zones ◽  
Hydrothermal Activity ◽  
Western Alps ◽  
Strike Slip ◽  
Quartz Veins ◽  
The North ◽  
Slip Regime ◽  
Tectonically Active ◽  
Dextral Strike Slip

Abstract U-Pb and Th-Pb dating of monazite from hydrothermal quartz veins (“Alpine veins”) from the Lauzière massif (North Belledonne) together with Ar/Ar ages of adularias from the same veins constrain the age of the last tectono-metamorphic events that affected the External Crystalline Massifs (ECM). Ages obtained are surprisingly young. The study of the structural context of the veins combined with our chronological data, allow us to propose a tectonic scenario of the northern ECM for the 15-5 Ma period, which was poorly documented so far. The quartz veins are of two types: (i) the oldest are poorly mineralized (chlorite and epidote), flat-lying veins. The quartz fibres (= extension direction) are near vertical and seem to be associated with a subvertical dissolution schistosity superimposed upon an early Alpine deformation underlined by “mini-biotite”. They bear a sub-horizontal stretching lineation; (ii) the youngest veins are very rich in various minerals (anatase, rutile, phénacite, meneghinite, beryl, synchysite, ….). They are almost vertical. Their “en echelon” geometry as well as the horizontal attitude of their quartz fibres show a dextral strike-slip regime. Two groups of Th-Pb ages have been obtained: 11 to 10 Ma and 7 to 5 Ma. They were obtained from the most recent veins (vertical veins) sampled in different areas of the massif. The ca. 10 Ma ages are related to veins in the Lauzière granite and its metamorphic country-rocks at about 2 km from the eastern contact of the massif, while the ages of ca. 5 Ma correspond to veins occurring in mylonites along this contact. Adularias provided Ar/Ar ages at ca. 7 Ma. By contrast, a monazite from a vein of the Pelvoux massif (Plan du Lac) yielded a Th-Pb age of 17.6 Ma but in a different structural setting. Except fission track ages, there are very little ages of this range published in the recent literature on the Alps. The latter concern always gold mineralized veins (NE Mont Blanc and SW Lepontine dome). The last compressive tectonic regime dated between 15 and 12 Ma is coeval with (i) the late “Roselend thrust” event, which is recorded in the Mont Blanc by shear-zones with vertical lineation, (ii) the last movements in the basal mylonites of the Swiss Nappes, (iii) the horizontal Alpine veins from the Mont Blanc and Belledonne massifs (with vertical quartz fibres), which are similar to the early veins of the Lauzière. On the contrary, the vertical veins of the Lauzière, dated between 11 and 5 Ma, correspond to a dextral strike slip regime. This suggests that most of the strike-slip tectonics along the ECM took place during two stages (ca. 10 Ma and ca. 7-5 Ma) and not only at 18 Ma as had been proposed previously. Our ages are consistent with the late Miocene-Pliocene overlap of the Digne thrust to the South and to part of the normal movement along the Simplon fault to the North. Thus, all the external crystalline massifs were tectonically active during the late Miocene. This suggests that tectonic events in the external alpine belt may have contributed to some extent to the geodynamical causes of the Messinian crisis.

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