40Ar-39Ar ages of the Louzidian-Dachengzi ductile shear zone near Chifeng, Inner Mongolia and their tectonic significance

2002 ◽  
Vol 47 (15) ◽  
pp. 1292 ◽  
Author(s):  
Xiaohui ZHANG
Keyword(s):  
Shear Zone ◽  
Inner Mongolia ◽  
Ductile Shear Zone ◽  
Tectonic Significance ◽  
Ductile Shear

Tectonic significance of the northeastern Gander Zone, Newfoundland: an Acadian ductile shear zone

1981 ◽  
Vol 18 (1) ◽  
pp. 120-135 ◽  
Author(s):  
Simon Hanmer
Keyword(s):  
Shear Zone ◽  
Strike Slip ◽  
Vertical Shear ◽  
Ductile Shear Zone ◽  
Tectonic Significance ◽  
Southeastern Margin ◽  
Thrust Zone ◽  
Appalachian Orogen ◽  
Geologic Model ◽  
Ductile Shear

Penetrative deformation and granite intrusion in the northeastern Gander Zone, Newfoundland, represent a progressive Acadian event. Interference between ductile, strike–slip shearing along the southeastern margin of the Appalachian orogen and the emplacement of syntectonic granite diapirs results in the formation of a vertical, northeast–southwest strike–slip ductile shear zone where granites come to outcrop and a ductile strike–slip thrust zone where granites are absent at the surface. Sinistral movement along the vertical shear zone is compatible with recent palaeomagnetic models for the Appalachians and the British Caledonides. The constraints that the geologic model places on the symmetry of the Appalachian orogen in Newfoundland and the definition and extrapolation of the Gander tectonostratigraphic zone are discussed.

Structural analysis of the Nanchang-Wanzai sinistral ductile shear zone (Jiangnan region, South China)

1991 ◽  
Vol 6 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Liangshu Shu ◽  
Jacques Charvet ◽  
Yangshen Shi ◽  
Michel Faure ◽  
Dominique Cluzel ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Shear Zone ◽  
South China ◽  
Ductile Shear Zone ◽  
Ductile Shear

40Ar/ 39Ar laser dating of Zongwulong ductile shear zone in northeastern Tibetan Plateau ：Constrains on the closure time of the northmost Paleo-Tethys ocean

2021 ◽  
Author(s):  
Wanli Gao ◽  
Zongxiu Wang
Keyword(s):  
Shear Deformation ◽  
Shear Zone ◽  
Ductile Deformation ◽  
Low Grade ◽  
Ductile Shear Zone ◽  
The South ◽  
Oblique Collision ◽  
Ductile Shear ◽  
Tethys Ocean ◽  
Tectonic Belt

<p><strong><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.67d6c7216eff55356050161/sdaolpUECMynit/12UGE&app=m&a=0&c=5572aca4b392eef83f52919e1be673e9&ct=x&pn=gepj.elif&d=1" alt="">Abstract</strong>：The Zongwulong tectonic belt (ZTB) is located between the northern Qaidam tectonic belt and the south Qilian orogenic belt and contains Late Paleozoic and Early- Middle Triassic strata. Structural features and geochronology of Zongwulong ductile shear zone have key implications for the tectonic property of the ZTB. This study integrated field structure, microscopic structure and <sup>40</sup>Ar/<sup>39</sup>Ar laser probe analysis. The shear zone strikes ~NEE-SWW and dips at a high angle, with a NWW-SEE trending and WE stretching lineation, indicating the shear zone as a thrust- slip shear ductile shear. The asymmetric folds, rotating porphyroclast,structural lens and crenulation cleavage can be seen in the field. Mica fish, S − C fabrics, σ type quartz porphyroclastic and quartz wire drawing structure can also be observed under microscope, indicating that the strike- slip- related ductile deformation and mylonitization occurred under low- grade greenschist facies conditions at temperatures of <em>300° C − 400° C</em>.  The highly deformed<br>mylonite schist yielded <sup>40</sup>Ar/<sup>39</sup>Ar ages <em>(245.8±1.7)Ma </em>and <em>(238.5±2.6)</em>Ma for muscovite and biotite, respectively, indicating that the shear deformation occurred during the Early- Mid Triassic. Combined with comprehensive analysis of regional geology and petrology, the authors hold that the age of ductile shear deformation represents the time of Triassic orogeny in the ZTB. The oroginic activity was probably related to the oblique collision between the South Qilian block and the Oulongbuluke block after the closure of the northermost Paleo-Tethys ocean.</p>

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