干旱区生态环境知识资源中心(Arid): Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination

Arid

	Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination
	Abd El-Wahed Mohamed; Kamh Samir; Ashmawy Mahmoud; Shebl Aly
来源期刊	Acta Geologica Sinica
ISSN	1000-9515
出版年	2019
卷号	93 期号:6 页码:1614-1646
英文摘要	Transpressional deformation has played an important role in the late Neoproterozoic evolution of the Arabian- Nubian Shield including the Central Eastern Desert of Egypt. The Ghadir Shear Belt is a 35 km-long, NW-oriented brittleductile shear zone that underwent overall sinistral transpression during the Late Neoproterozoic. Within this shear belt, strain is highly partitioned into shortening, oblique, extensional and strike-slip structures at multiple scales. Moreover, strain partitioning is heterogeneous along-strike giving rise to three distinct structural domains. In the East Ghadir and Ambaut shear belts, the strain is pure-shear dominated whereas the narrow sectors parallel to the shear walls in the West Ghadir Shear Zone are simple-shear dominated. These domains are comparable to splay-dominated and thrust-dominated strike-slip shear zones. The kinematic transition along the Ghadir shear belt is consistent with separate strike-slip and thrustsense shear zones. The earlier fabric(S_1), is locally recognized in low strain areas and SW-ward thrusts. S_2 is associated with a shallowly plunging stretching lineation(L_2), and defines ~NW-SE major upright macroscopic folds in the East Ghadir shear belt. F_2 folds are superimposed by ~NNW-SSE tight-minor and major F_3 folds that are kinematically compatible with sinistral transpressional deformation along the West Ghadir Shear Zone and may represent strain partitioning during deformation. F_2 and F_3 folds are superimposed by ENE-WSW gentle F_4 folds in the Ambaut shear belt. The sub-parallelism of F_3 and F_4 fold axes with the shear zones may have resulted from strain partitioning associated with simple shear deformation along narrow mylonite zones and pure shear-dominant deformation in fold zones. Dextral ENEstriking shear zones were subsequently active at ca. 595 Ma, coeval with sinistral shearing along NW- to NNW-striking shear zones. The occurrence of upright folds and folds with vertical axes suggests that transpression plays a significant role in the tectonic evolution of the Ghadir shear belt. Oblique convergence may have been provoked by the buckling of the Hafafit gneiss-cored domes and relative rotations between its segments. Upright folds, fold with vertical axes and sinistral strike-slip shear zones developed in response to strain partitioning. The West Ghadir Shear Zone contains thrusts and strikeslip shear zones that resulted from lateral escape tectonics associated with lateral imbrication and transpression in response to oblique squeezing of the Arabian-Nubian Shield during agglutination of East and West Gondwana.
英文关键词	Arabian-Nubian Shield Ghadir shear belt transpression splay-dominated and thrust-dominated strike-slip shear zones Egypt
类型	Article
语种	英语
收录类别	CSCD
WOS研究方向	Geology
CSCD记录号	CSCD:6632453
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/336229
作者单位	Abd El-Wahed Mohamed, Geology Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Kamh Samir, Geology Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Ashmawy Mahmoud, Geology Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Shebl Aly, Geology Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
推荐引用方式 GB/T 7714	Abd El-Wahed Mohamed,Kamh Samir,Ashmawy Mahmoud,et al. Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination[J],2019,93(6):1614-1646.
APA	Abd El-Wahed Mohamed,Kamh Samir,Ashmawy Mahmoud,&Shebl Aly.(2019).Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination.Acta Geologica Sinica,93(6),1614-1646.
MLA	Abd El-Wahed Mohamed,et al."Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination".Acta Geologica Sinica 93.6(2019):1614-1646.