scholarly journals Age and tectonic evolution of Neoproterozoic ductile shear zones in southwestern Madagascar, with implications for Gondwana studies

Tectonics ◽  
2001 ◽  
Vol 20 (1) ◽  
pp. 1-45 ◽  
Author(s):  
Maarten J. de Wit ◽  
Sam A. Bowring ◽  
Lew D. Ashwal ◽  
Leon G. Randrianasolo ◽  
Vincent P. I. Morel ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Shear Zones ◽  
Ductile Shear Zones ◽  
Ductile Shear

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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