The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt

2006 ◽  
Vol 46 (3) ◽  
pp. 201-220 ◽  
Author(s):  
Abdel-Rahman Fowler ◽  
Khaled G. Ali ◽  
Sayed M. Omar ◽  
Hassan A. Eliwa
Keyword(s):  
Shear Zones ◽  
Eastern Desert ◽  
The North ◽  
Ductile Shear Zones ◽  
North Eastern ◽  
Ductile Shear

Structural analysis of ductile shear zones in the North Qinling Orogen and its implications for the evolution of the Proto-Tethys Ocean

2017 ◽  
Vol 52 ◽  
pp. 202-214 ◽  
Author(s):  
Shujuan Zhao ◽  
Sanzhong Li ◽  
Xiyao Li ◽  
Ian Somerville ◽  
Huahua Cao ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Shear Zones ◽  
Qinling Orogen ◽  
The North ◽  
Ductile Shear Zones ◽  
North Qinling ◽  
Ductile Shear ◽  
Tethys Ocean

Strain-induced mineral growth in ductile shear zones and a preliminary study of ductile shearing in western Newfoundland

1988 ◽  
Vol 25 (12) ◽  
pp. 2118-2129 ◽  
Author(s):  
M. A. J. Piasecki
Keyword(s):  
Growth Characteristic ◽  
Shear Zones ◽  
The North ◽  
Mineral Growth ◽  
Inclined Surfaces ◽  
Ductile Shear Zones ◽  
Ductile Shearing ◽  
Preliminary Study ◽  
Ductile Shear ◽  
North And South

In the Fleur de Lys and the Central Gneiss terranes the presence of strain-induced mineral growth characteristic of ductile shear zones within zones of rocks with mylonitic fabrics indicates the existence of major belts of layer-parallel ductile shearing with complex evolutionary sequences. Kinematic markers in several of these shear belts indicate that shearing movements on initially probably gently inclined surfaces, directed not normal to the axial trend of the orogen but parallel to it, are tectonically important in western Newfoundland. The shear belts are in excess of 1 km thick, and one well-exposed example exhibits a pattern in which zones of the highest strain anastomose on the map scale.The base of the Fleur de Lys Supergroup is marked by one such major zone of shearing (décollement) in which kinematic indicators record movements directed to the north and to the south, before the regional attitude of the rocks was steepened. Along the Baie Verte Line, earlier north- and south-directed movements in the Fleur de Lys were succeeded by reverse movements towards the east, over the Dunnage Terrane.

Neoarchean tectonics: insight from the deformation of the Archean basement of North China Craton

2020 ◽  
Author(s):  
Yongjiang Liu ◽  
Jing Li ◽  
Weimin Li ◽  
Sanzhong Li ◽  
Liming Dai
Keyword(s):  
North China Craton ◽  
Tectonic Evolution ◽  
North China ◽  
Shear Zones ◽  
Banded Iron Formations ◽  
The North ◽  
Detailed Structural Analysis ◽  
Ductile Shear Zones ◽  
Ductile Shear ◽  
Iron Formations

<p>The controversy over the Archean tectonic regimes has lasted several decades focusing around horizontal and vertical tectonics, the two classical tectonic models for Archean times. Thus, more studies of the early crustal growth and tectonic evolution are requisite for better understanding geodynamic regimes in the early Precambrian. The North China Craton is one of the major Archean to Paleoproterozoic cratons in the world and oldest craton in China, which preserves a large amount of ancient basement and abundant structures showing the early earth tectonics.</p><p>In this study, we have carried out detailed structural analysis of two down-slip ductile shear zones which developed in eastern Anshan area and provided an example for revealing of Neoarchean vertical tectonics in the study area. There were also develop many structures of dome and keel style in the North China Craton, such as Qian ’an, Qingyuan areas.</p><p>Based on abundant structural evidence and previous studies, we infer that the vertical tectonics is still the dominant model for Neoarchean crust growth and tectonic evolution in Anshan area. The formation of dome and keel structure, and the deformation of the down-slip ductile shear zones may have resulted from the sagduction of the banded iron formations and synchronous Archean granite dome emplacement, supporting a vertical tectonic regime in Archean times.</p>

Indentation tectonics of the Zhongtiaoshan Block in the Trans-North China Orogen

2020 ◽  
Author(s):  
Jiawei Cui
Keyword(s):  
Tectonic Evolution ◽  
North China ◽  
Shear Zones ◽  
Middle Part ◽  
Granitic Gneiss ◽  
Northern Margin ◽  
The North ◽  
Ductile Shear Zones ◽  
Ductile Shear ◽  
Changcheng System

<p><span>The North China (NCC) is one of the oldest cratons in the world. The tectonic evolution processes of the NCC have been debated for decades (Zhao and Zhai, 2013; Zhao, 2007; Zhao et al., 2002, 2003, 2005, 2009; Zhai et al., 2005; Zhai and Santosh, 2011; Wilde et al., 2002, 2005; Kroner et al., 2005; Kusky et al., 2001, 2007; Kusky and Li, 2003; Faure et al., 2007; Trap et al., 2012; Hu et al., 2013; Zhao et al.,2019). The controversy focuses on the time of the formation of the NCC is in the late Paleoproterozoic or the late Archean. The key point of the controversy is that there are serious disagreement about the nature and implications of the late Paleoproterozoic orogen in the NCC. Some researchers thought the NCC underwent compression in 1.85 Ga according to previous researchers (Zhai et al., 2005; Zhai and Santosh, 2011; Zhao et al., 2019). Some researchers even thought that the NCC was finally formed resulted from the collision of the east block and the west block</span><span> (Kusky et al., 2001, 2007; Kusky and Li, 2003; </span><span>Trap et al., 2012; Zhao et al., 2002a, 2003a, 2005, 2009;). Recently, we found that NE-NEE trending extensional ductile shear zones developed in the Paleoproterozoic granitic gneiss (2.4Ga) in the northern margin of the Zhongtiaoshan, the middle part of the NCC. The ductile shear zone was unconformity covered by the Changcheng System and the deformation ages according to the <sup>40</sup>Ar/<sup>39</sup>Ar dating results is 1.92 Ga, which indicate that the deformation time was in the late Paleoproterozoic. Therefore, We propose that that the NCC was in the post-collision extension environment or lateral and vertical extrusion of blocks might have happened after the orogeny</span> <span>in late Paleoproterozioc.</span></p>

LONGEVITY OF DUCTILE SHEAR ZONES FROM DIFFUSION GEOSPEEDOMETRY OF KINEMATICALLY-SENSITIVE MINERAL INCLUSIONS

2019 ◽  
Author(s):  
William O. Nachlas ◽  
◽  
Christian Teyssier ◽  
Donna L. Whitney ◽  
Greg Hirth
Keyword(s):  
Shear Zones ◽  
Mineral Inclusions ◽  
Ductile Shear Zones ◽  
Ductile Shear
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