Strain analysis and deformation history of Zalm area, Arabian Shield, Saudi Arabia
, Kahal, A. Y., Abd El-Motaal, E., Kassema O.M.K. and Al Ghoreiby, A.H.R. . 2019
The present work deals with the strain analysis and deformation of the Zalm area which is located in the central
part of the central Nabitah suture belt, which separates the continental Afif terrane from the ensimatic arc
terranes of the western Arabian Shield. This study carried out through field investigation, strain parameters, and
microscopic examination for understanding the nature of deformation in the Zalm area. On the basis of the field
investigation and the geometry of the contact, it is more likely that the contact between ultramafic rocks and
gabbroic rock complex is low-angle thrust faulting. The granitoid rocks are divided into the quartz monzodiorite,
monzogranite, alkali-feldspar granite and leucocratic-granodiorite. The Rf/ϕ and Fry techniques on feldspar and
mafic grains from 53 samples representative of each rock type were collected in the field. Strain data shows that
the deformation of the granitic, metavolcanic and amphibole schist samples range from high to moderate. The
axial ratios (XZ section) range from 1.60 to 4.10 for the Rf/ϕ method and 2.80 to 4.90 for the Fry method.
Furthermore, the finite strain data does not dispay any significant difference in the deformation behavior between
Rf/ϕ and Fry methods. We concluded that the strain magnitude has the same order of deformation in the
deformed granitoid and amphibole schist rocks. The majority of samples are in a zone of flattening symmetry,
while a few samples are showing constrictional symmetry. In addition, it is noted that the short axes (Z) are subperpendicular related with a sub-parallel foliation. Furthermore, the nappe contact are designed during the
intrusion of plutons associated with faults in the Zalm regions under brittle to semi-ductile deformation conditions.
Bauxite samples from deposits in northern Saudi Arabia were identified in the laboratory using spectral reflectance measurements
(at 0.3–2.5 μm) and X-ray diffraction (XRD). The XRD results…
The Tihamat-Asir area is located in southwest Saudi Arabia between the Asir Mountains and the Red Sea coast.
Herein, the Tihamat-Asir area aeromagnetic data are re-interpreted to explain the…
The present work deals with the strain analysis and deformation of the Zalm area which is located in the central
part of the central Nabitah suture belt, which separates the continental Afif…