TY - JOUR
T1 - Remote sensing and structural studies of the Central Asir Shear Zone, Western Arabian Shield
T2 - Implications for the late Neoproterozoic E-W Gondwana assembly
AU - Hamimi, Zakaria
AU - Abdelkareem, Mohamed
AU - Fowler, Abdel Rahman
AU - Younis, Mohammed H.
AU - Matsah, Mohammed
AU - Abdalla, Fathy
N1 - Funding Information:
The authors would like to extend their sincere appreciation to the Guest Editors of the Special Issue, Ahmed Hassan Ahmed, Hassan Helmy and Amara Masrouhi, for their kind invitation to contribute this volume. Dr. Abdalla would like to thank the Deanship of Scientific Research, King Saud University for support through Vice Deanship of Scientific Research Chairs.
Publisher Copyright:
© 2021
PY - 2021/8/1
Y1 - 2021/8/1
N2 - The Central Asir Shear Zone (CASZ) is a N- to NNE-oriented inhomogeneous strain zone parallel to the Nabitah shear belt in southern Saudi Arabia. It is ~200 km long and 20 km wide, and traverses the Asir terrane. The deformed terrains in the vicinity of the CASZ have experienced a prolonged history involving three successive phases of deformation: arc-collision, dextral transpression and sinistral strike-slip faulting. Remote-sensing data analysis and field investigation provide insights into the geological and structural features along the CASZ. Image transformation and enhancement reveal faults and folds, and discriminate between granitoids, metavolcanics, gabbros and younger (Ablah Group) sediments. The obtained evidence points to polyphase deformation of the area, characterized by narrow zones of high strain, folding and shearing enclosing slices of less deformed rocks. Lineament analysis shows predominantly NNE, NNW, N and NE trends of folds and shear zones, and NW, NE and E fracture trends. The CASZ has a >100 m.y. long deformation history, including a change from dextral to sinistral shearing. Both shearing senses are found on the older N-S and younger NW-SE fault systems. N-S oriented shearing was accompanied by intrusion of granitoids and localized hydrothermal alteration along N to NNE trending shear zones. Strain analysis shows low strain in the Ablah basin sediments, consistent with Ablah deposition after the tectonic climax in the region.
AB - The Central Asir Shear Zone (CASZ) is a N- to NNE-oriented inhomogeneous strain zone parallel to the Nabitah shear belt in southern Saudi Arabia. It is ~200 km long and 20 km wide, and traverses the Asir terrane. The deformed terrains in the vicinity of the CASZ have experienced a prolonged history involving three successive phases of deformation: arc-collision, dextral transpression and sinistral strike-slip faulting. Remote-sensing data analysis and field investigation provide insights into the geological and structural features along the CASZ. Image transformation and enhancement reveal faults and folds, and discriminate between granitoids, metavolcanics, gabbros and younger (Ablah Group) sediments. The obtained evidence points to polyphase deformation of the area, characterized by narrow zones of high strain, folding and shearing enclosing slices of less deformed rocks. Lineament analysis shows predominantly NNE, NNW, N and NE trends of folds and shear zones, and NW, NE and E fracture trends. The CASZ has a >100 m.y. long deformation history, including a change from dextral to sinistral shearing. Both shearing senses are found on the older N-S and younger NW-SE fault systems. N-S oriented shearing was accompanied by intrusion of granitoids and localized hydrothermal alteration along N to NNE trending shear zones. Strain analysis shows low strain in the Ablah basin sediments, consistent with Ablah deposition after the tectonic climax in the region.
KW - Arabian Shield
KW - Asir terrane
KW - Central Asir Shear Zone
KW - East African Orogen
KW - Structural analysis
UR - http://www.scopus.com/inward/record.url?scp=85105442178&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85105442178&partnerID=8YFLogxK
U2 - 10.1016/j.jseaes.2021.104782
DO - 10.1016/j.jseaes.2021.104782
M3 - Article
AN - SCOPUS:85105442178
SN - 1367-9120
VL - 215
JO - Journal of Asian Earth Sciences
JF - Journal of Asian Earth Sciences
M1 - 104782
ER -