scholarly journals Early Jurassic Rifting of the Arabian Passive Continental Margin of the Neo-Tethys. Field Evidence From the Lurestan Region of the Zagros Fold-and-Thrust Belt, Iran

Tectonics ◽  
2018 ◽  
Vol 37 (8) ◽  
pp. 2586-2607 ◽  
Author(s):  
Stefano Tavani ◽  
Mariano Parente ◽  
Stefano Vitale ◽  
Alessandro Iannace ◽  
Amerigo Corradetti ◽  
...  
Keyword(s):  
Continental Margin ◽  
Early Jurassic ◽  
Passive Continental Margin ◽  
Thrust Belt ◽  
Field Evidence ◽  
Fold And Thrust Belt

The crustal structure in the transition from the on land fold-and-thrust belt to the offshore accretionary prism in the Taiwan arc-continent collision

2020 ◽  
Author(s):  
Joaquina Alvarez-Marrón ◽  
Dennis Brown ◽  
Juan Alcalde ◽  
Ignacio Marzán ◽  
Hao Kuo-Chen
Keyword(s):  
Continental Margin ◽  
Seismic Tomography ◽  
Accretionary Prism ◽  
Crustal Thickening ◽  
Accretionary Wedge ◽  
Thrust Belt ◽  
Deformation Front ◽  
Coast Line ◽  
Transition Area ◽  
Fold And Thrust Belt

<p>The region of Taiwan is undergoing active, oblique arc-continent colision between the Luzon Arc on the Philippine Sea Plate and the continental margin of Eurasia. The Fold-and-Thrust Belt (FTB) in Taiwan passes southwards into a submarine accretionary wedge at the Manila subduction zone. The aim of this contribution is to examine how an on land FTB changes into a marine accretionary prism in the context of an oblique arc-continent collision. The Miocene pre-orogenic sediments of the continental margin are widespread in the FTB ca. 23° latitude while the offshore wedge is built up dominantly by Pliocene to recent syn-orogenic sediments. In the transition area from the marine accretionary wedge ca. 21° latitude to the on land FTB, the thrust wedge is climbing up the slope of the Eurasian continental margin. The deformation front is at sea floor depth of ca. 4 km in the south to less than 1 km as it reaches the coast line. Here we use the island surface geology, marine reflection seismic profiles, and seismic tomography models to construct contour maps of the basal thrust and the depth to the Moho across a transition area from near 23° to near 21° latitude. In this zone, the deformation front draws a convex curvature as the wedge widens from ca. 50 in the north and south, to more than 130 km near 22° latitude. The basal thrust surface shows a scoop shape as its dip changes from southeast near the coast line to east southward. The basal thrust reaches over 7 km deep beneath the rear of the FTB before ramping into de basement and merging into the Chaochou fault at 10 km depth. Offshore, it shows a gentler dip from 7 km to c. 10 km depth before getting steeper towards the east below the Hengchung Ridge. The basal cuts laterally along-strike through the margin’s sedimentary cover to incorporate thicker Miocene pre-orogenic sediments onto its hanging wall as it passes from the offshore wedge to the on land FTB.</p><p>In the offshore area, the Moho (we use a Vp proxy of 7.5 km/s extracted from the seismic tomography) shallows southeastward, from near 25 km depth below the shelf slope break to less than 17 km depth below the offshore wedge near 21.5° latitude before it starts to deep east towards beneath the Taiwan coast. The Moho dips northeast from near 25 km depth below the coast near Kaohsiung, to near 40 depth below the rear of the FTB at 23.5°, latitude. This complex morphology of the Moho may be related to the changes in crustal thickness and the obliquity of the collision. Because of this, crustal thickening is less pronounced beneath southern Taiwan where the thinner part of the margin is colliding with the arc.</p><p>This research is part of project PGC2018-094227-B-I00 funded by the Spanish Research Agency from the Ministry of Science Innovation and Universities of Spain.</p>

scholarly journals How the structural architecture of the Eurasian continental margin affects the structure, seismicity, and topography of the south central Taiwan fold-and-thrust belt

Tectonics ◽  
2017 ◽  
Vol 36 (7) ◽  
pp. 1275-1294 ◽  
Author(s):  
Dennis Brown ◽  
Joaquina Alvarez-Marron ◽  
Cristina Biete ◽  
Hao Kuo-Chen ◽  
Giovanni Camanni ◽  
...  
Keyword(s):  
Continental Margin ◽  
Thrust Belt ◽  
The South ◽  
South Central ◽  
Fold And Thrust Belt ◽  
Central Taiwan ◽  
Structural Architecture

scholarly journals The influence of inherited continental margin structures on the stress and strain fields of the south-central Taiwan fold-and-thrust belt

2019 ◽  
Vol 219 (1) ◽  
pp. 430-448
Author(s):  
Cristina Biete ◽  
Dennis Brown ◽  
Björn Lund ◽  
Joaquina Alvarez-Marron ◽  
Yih-Min Wu ◽  
...  
Keyword(s):  
Strain Rate ◽  
Continental Margin ◽  
Displacement Field ◽  
Stress And Strain ◽  
Thrust Belt ◽  
The South ◽  
Strain Fields ◽  
South Central ◽  
Fold And Thrust Belt ◽  
Central Taiwan

SUMMARY In this paper we test whether or not structural and morphological features inherited from the Eurasian continental margin are affecting the contemporary stress and strain fields in south-central Taiwan. Principal stress directions (σ1, σ2 and σ3) are estimated from the inversion of clustered earthquake focal mechanisms and the direction of the maximum compressive horizontal stress (SH) is calculated throughout the study area. From these data the most likely fault plane orientations and their kinematics are inferred. The results of the stress inversion are then discussed together with the directions of displacement, compressional strain rate and maximum shear strain rate derived from GPS data. These data show that there is a marked contrast in the direction of SH from north to south across the study area, with the direction of SH remaining roughly subparallel to the relative plate motion vector in the north, whereas in the south it rotates nearly 45° counter-clockwise. The direction of the horizontal maximum compression strain rate (εH) and associated maximum shear planes, together with the displacement field display an overall similar pattern between them, although undergoing a less marked rotation. We interpret the southward change in the SH, εH and the dextral maximum shear plane directions, together with that of the horizontal displacement field to be related to the reactivation of east–northeast striking faults inherited from the rifted Eurasian margin and to the shelf/slope break. Inherited faults in the basement are typically reactivated as strike-slip faults, whereas newly formed faults in the fold-and-thrust belt are commonly thrusts or oblique thrusts. Eastwards, the stress inversions and strain data show that the western flank of the Central Range is undergoing extension in the upper crust. SH in the Central Range is roughly parallel to the relative plate convergence vector, but in southwestern Taiwan it undergoes a marked counter-clockwise rotation westwards across the Chaochou fault. Farther north, however, there is no significant change across the Lishan fault. This north to south difference is likely due to different margin structures, although local topographic effects may also play a role.

Timing and origin of deformation along the Patagonian fold and thrust belt

2000 ◽  
Vol 137 (4) ◽  
pp. 345-353 ◽  
Author(s):  
M. SUÁREZ ◽  
R. DE LA CRUZ ◽  
C. M. BELL
Keyword(s):  
Continental Margin ◽  
Foreland Basin ◽  
South American ◽  
Thrust Belt ◽  
The South ◽  
Plate Convergence ◽  
Ridge Subduction ◽  
Fold And Thrust Belt ◽  
Chile Ridge ◽  
Oceanic Plates

The Andean orogeny in the Patagonian Cordillera of southern South America reflects the consequences of the Mesozoic and Cenozoic subduction of an oceanic plate beneath the South American continental margin. The geological evolution of the region has been influenced by the Eocene collision and subduction of the Farallon–Aluk Ridge and the Miocene–Recent subduction of the Chile Ridge. Another aspect of plate interaction during this period was two intervals of rapid plate convergence, one at 50–42 Ma, and the other at 25–10 Ma, between the South American and the oceanic plates. It has been proposed that the collision of the Chile Ridge with the trench was responsible for the development, at least in part, of the Patagonian fold and thrust belt. This belt extends for more than 1000 km along the eastern foothills of the southern Andes between 46° and 54° S along the southwestern rim of the Austral Basin. The interpretation of a link between subduction of the ridge and formation of the fold and thrust belt is based on assumed time coincidences between contractional tectonism and the collision of ridge segments during Middle and Late Miocene times. The main Tertiary contractional events in the Patagonian fold and thrust belt took place during latest Cretaceous–Palaeocene–Eocene and during Miocene times. Although the timing of deformation is still poorly constrained, the evidence currently available suggests that there is little or no relationship between the timing of the fold and thrust belt and the collision of ridge segments. Most if not all of the contractional tectonism pre-dated the latest episodes of ridge collision. Collision of a ridge crest with the continental margin has been active for the past 14 to 15 million years. Contrary to the suggestion of a relationship between ridge subduction and compression, the main result of this collision has been fast uplift and extensional tectonism. The initiation of the Patagonian fold and thrust belt in latest Cretaceous or early Tertiary times coincided with a fundamental change in the tectonic evolution of the Austral Basin. Throughout the Cretaceous most of this basin subsided as a broad backarc continental shelf. Only in latest Cretaceous times, and coinciding with the initiation of the fold and thrust belt, the basin underwent a transition to a retro-arc foreland basin. This change to an asymmetrically subsiding foreland basin, with an associated foreland fold and thrust belt, was related to uplift of the Andean orogenic belt in the west.

U–Pb ages for magmatism and deformation in the New Quebec Orogen

1997 ◽  
Vol 34 (5) ◽  
pp. 716-723 ◽  
Author(s):  
N. Machado ◽  
T. Clark ◽  
J. David ◽  
N. Goulet
Keyword(s):  
Lower Limit ◽  
Continental Margin ◽  
Detrital Zircons ◽  
Passive Continental Margin ◽  
Source Rocks ◽  
Sedimentary Sequences ◽  
Deformational History ◽  
Fold And Thrust Belt ◽  
History Of ◽  
Magmatic Event

The New Quebec Orogen is a Paleoproterozoic fold and thrust belt, active from 2.17 to 1.77 Ga, bordering the eastern margin of the Archean Superior Province. The orogen developed on a long-lived, passive continental margin and comprises two volcanic – sedimentary sequences. The ages presented in this study help to bracket the magmatic and deformational history of the orogen. A glomeroporphyritic gabbro from the Hellancourt Formation was dated at 1874 ± 3 Ma and a rhyodacite from the upper Murdoch Formation yielded an identical age of 1870 ± 4 Ma. These data allow the correlation of the two units and indicate that they are 10–14 Ma younger than the estimated age for the Sokoman Formation. These ages, together with already published work, indicate that magmatism related to the younger magmatic event occurred at 1884–1870 Ma. Albitized pelites from the Murdoch Formation contain euhedral detrital zircons 2707–2690 Ma old, indicating that the source rocks were Archean. An undeformed monzonitic intrusion occurring close to Nachicapau Lake is 1813 ± 4 Ma old and is the lower limit for the age of deformation in the central sector of the orogen.

Paleoseismology of a newly discovered scarp in the Yakima fold-and-thrust belt, Kittitas County, Washington

2013 ◽  
Author(s):  
Elizabeth A. Barnett ◽  
Brian L. Sherrod ◽  
Robert Norris ◽  
Douglas Gibbons
Keyword(s):  
Thrust Belt ◽  
Fold And Thrust Belt
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